OFFICE OF THE FEDERAL COORDINATOR

FOR METEOROLOGICAL SERVICES AND 

SUPPORTING RESEARCH

U.S. DEPARTMENT OF COMMERCE/National Oceanic and Atmospheric Administration

OFCM

WEATHER INFORMATION FOR

SURFACE TRANSPORTATION

NATIONAL NEEDS ASSESSMENT REPORT

FCM-R18-2002
THE FEDERAL COMMITTEE FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

VADM CONRAD C. LAUTENBACHER, JR., USN (RET.), Chairman

Department of Commerce

VACANT

Office of Science and Technology Policy

DR. RAYMOND MOTHA

Department of Agriculture

BRIG. GEN. JOHN J. KELLY, JR., USAF (RET.)

Department of Commerce

CAPT FRANK GARCIA, USN

Department of Defense

DR. ARISTIDES PATRINOS

Department of Energy

DR. ROBERT M. HIRSCH

Department of the Interior

MR. RALPH BRAIBANTI

Department of State

MR. JAMES H. WASHINGTON

Department of Transportation

MR. HENRY L. LONGEST (Acting)

Environmental Protection Agency

MR. ANTHONY LOWE

Federal Emergency Management Agency

DR. GHASSEM R. ASRAR

National Aeronautics and Space Administration

DR. MARGARET S. LEINEN

National Science Foundation

MR. PAUL MISENCIK

National Transportation Safety Board

MR. JACK R. STROSNIDER

Nuclear Regulatory Commission

MR. RANDOLPH LYON

Office of Management and Budget

MR. SAMUEL P. WILLIAMSON

Federal Coordinator

MR. JAMES B. HARRISON, Executive Secretary

Office of the Federal Coordinator for

Meteorological Services and Supporting Research

THE INTERDEPARTMENTAL COMMITTEE FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

MR. SAMUEL P. WILLIAMSON, Chairman

Federal Coordinator

MR. THOMAS PUTERBAUGH

Department of Agriculture

MR. JOHN E. JONES, JR.

Department of Commerce

CAPT FRANK GARCIA, USN

Department of Defense

MR. RICKEY PETTY

Department of Energy

MR. LEWIS T. MOORE

Department of the Interior

MR. JEFFREY MACLURE

Department of State

MR. DAVID WHATLEY

Federal Aviation Administration

Department of Transportation

DR. JONATHAN M. BERKSON

U. S. Coast Guard

Department of Transportation

DR. S. T. RAO

Environmental Protection Agency

MR. JOHN GAMBEL

Federal Emergency Management Agency

DR. RAMESH KAKAR

National Aeronautics and Space Administration

DR. JARVIS MOYERS

National Science Foundation

MR. DONALD E. EICK

National Transportation Safety Board

MS. LETA A. BROWN

Nuclear Regulatory Commission

MS. ERIN WUCHTE

Office of Management and Budget

MR. JAMES B. HARRISON, Executive Secretary

Office of the Federal Coordinator for

Meteorological Services and Supporting Research

Front Cover Photo Credits (clockwise from top left)

Flooded rails: OFCM photo library

USCGC Mackinaw: Courtesy, USCG 9th District

Schoolbus in fog: Courtesy, Mr. Blaine K. Tsugawa

Hurricane evacuation: Courtesy, AP Wide World Photos

Highway crash in morning fog: OFCM photo library
OFFICE OF THE FEDERAL COORDINATOR

FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

8455 Colesville Road, Suite 1500

Silver Spring, Maryland 20910

WEATHER INFORMATION FOR SURFACE TRANSPORTATION

NATIONAL NEEDS ASSESSMENT REPORT

FCM-R18-2002

Washington, DC

December 2002
iii

Foreword

Surface transportation in the United States faces significant weather threats on a nearly

continuous basis. This report provides a compilation of weather information needs across the six

surface transportation sectors--roadway, railway, transit, marine transportation, pipeline systems,

and airport ground operations--and an analysis of these needs. The findings in the report provide

a framework for actions to substantially improve surface transportation operations in the future.

In September 1998, the Federal Committee for Meteorological Services and Supporting Research

(FCMSSR) was briefed on the Office of Federal Coordinator for Meteorology (OFCM) “Look to

the Future.” The briefing identified priority areas, issues, problems, and ideas to improve the

effectiveness of interagency coordination and cooperation. Surface transportation needs

(including ground and marine transportation modes) were emphasized. Weather support for

surface transportation was described as minimal and safety and economic productivity were at

stake. Coordination among the Federal Highway Administration (FHWA), other partners from

the Departments of Transportation and Commerce, state and local entities, and others in the

public and private sectors would be essential for defining requirements and developing tailored

decision aids. The FCMSSR agreed on the importance of addressing users’ needs for weather

information for surface transportation (WIST) through a coordinated effort.

Subsequently, the Interdepartmental Committee for Meteorological Services and Supporting

Research (ICMSSR) directed that a Joint Action Group be formed to address mission needs and

meteorological requirements for surface transportation. Two WIST symposia followed; the first

(November - December 1999) helped to identify WIST user needs, and the second (December

2000) reviewed the progress of compiling and analyzing the data collected over the previous

year. FCMSSR endorsed the continuation of this process in November 2000.

As I review this report in its final form, I want to emphasize four significant points:

• Environmental Support to Homeland Security. Most of the effort to identify, compile,

and analyze WIST needs occurred prior to the tragic events of September 11, 2001.

Nonetheless, there were WIST needs identified in each of the transportation sectors that are

directly relevant to our national resolve to be better prepared for any future acts of terrorism.

For example, airport ground operations will continue to be an important nexus of weatherrelated and security concerns. As a second example, a nationwide network (or

“infostructure”) to collect key transportation performance information, including road

weather data, will support the needs of emergency services personnel for more timely

information. Public and private entities would also be able to use this information to create

more accurate models of atmospheric dispersion, in the event of an atmospheric release of

hazardous materials. WIST will play a critical role in emergency preparedness at all levels of

federal, state, and local planning and response. We have known this for a long time with

respect to preparedness for natural disasters. Now we also need better weather information

to support the emergency response to disasters inflicted on our communities by those who

would do us harm.
iv

• The Twin Values of Safety and Economic Productivity. The report demonstrates how the

sometimes competing values of safety and economic benefits are closely intertwined when

we consider the potential for improving the information available to all those who make

decisions concerning surface transportation systems and activities. From the templates in this

report, we find that many of the impacts that increase costs, slow down a transportation

activity, or divert resources from other tasks result from actions necessary to mitigate risks to

the safety of personnel across the spectrum of transportation sector activities. By meeting the

requirements for provision of WIST to users, as outlined in this report, we can often

increase safety and realize economic benefits at the same time.

• Primary Use for Decision Support. In a sense we have always used weather information as

one input into life’s daily decisions: what to wear, when to plant or harvest, whether to move

up or delay a shipment or a ship. This study corroborates and expands on a key point made in

numerous other technical and program documents on transportation weather. The weather

information provider community must better understand how users can incorporate more

detailed weather information (which is also more accurate and at finer spatial and temporal

scales) in operational decision-making processes. These can be as simple as the new “511”

telephone advisory services for travelers, or any of the prototype demonstration projects

underway today. The ultimate test of these systems will be their acceptance by the users.

• Essential Cooperation among Weather Information Providers. The report stresses that

the broad requirements for provision of weather information to meet surface transportation

needs fall on the weather information provider community as a whole. The specificity and

detail of information needed for individual users speak to important and expanding roles for

private sector providers. The federal agency partners can provide basic weather and

environmental observations and forecasts, encourage the transfer of research results into

operations, and support the fundamental research and technology innovation needed to

advance the state of the art. The report’s use of the term “information provider community”

is not a euphemism. Success in meeting these requirements will entail cooperative efforts

and working partnerships among federal agencies; among federal, state, and “privatepublic” entities; and between the governmental and commercial sectors.

I wish to thank all those who participated and contributed to this report, particularly the many

nonfederal participants, from whom we learned a great deal. The WIST Needs Templates, which

constitute Appendix B of this report, derive much of their value from validation by

representatives of the six surface transportation sectors. I am indebted to the members of the

FCMSSR and ICMSSR for their support and guidance and to the members of the Joint Action

Group for Weather Information for Surface Transportation for their perseverance. Without this

support, our ability to identify and resolve specific, time-critical issues and projects would not

have been possible.

The WIST project does not end with this report. The process is dynamic; support capabilities

mature; and future needs evolve. Even the most successful weather information system requires

nurturing and maintenance to remain healthy and relevant. It remains for us, the readers, and

particularly the weather service providers, to make maximum use of this information on WIST
v

needs and requirements. We must re-invigorate existing support capabilities, initiate creative

new solutions, and exercise judicious use of assets to maximize the cooperative interests of

government and private sector participants for the benefit of the surface transportation public we

serve.

Samuel P. Williamson

Federal Coordinator for Meteorological Services

and Supporting Research
vii

Weather Information For Surface Transportation

Table of Contents

Foreword.............................................................................................................................................. iii

Table of Contents................................................................................................................................ vii

List of Figures...................................................................................................................................... xi

Tables.................................................................................................................................................. xii

Executive Summary ........................................................................................................................ ES-1

1. Introduction and Background ........................................................................................................ 1-1

1.0 Introduction. .......................................................................................................................... 1-1

1.1 Why Should We Be Concerned?........................................................................................... 1-3

1.1.1 Adverse Weather and the Nation’s Streets and Highways........................................... 1-3

1.1.2 Adverse Weather and Other Surface Transportation Sectors ...................................... 1-5

1.2 Exposures, Threats, and Risks are Increasing ....................................................................... 1-8

1.3 Meeting WIST Needs—The Time is Right!........................................................................ 1-11

1.3.1 The Potential for Existing and Emerging Technology to Meet WIST Needs............ 1-12

1.3.2 Expanding the Fundamental Knowledge Base for New Capabilities ........................ 1-17

1.3.3 Aviation Weather and Surface Transportation Weather ........................................... 1-18

1.4 Roles and Responsibilities of Information Users and Providers ......................................... 1-20

1.5 The Path Forward ................................................................................................................ 1-20

1.5.1 Initial Endorsement for a Coordinated WIST Effort ................................................. 1-21

1.5.2 FCMSSR Endorsement for Continuing the WIST Effort .......................................... 1-23

1.5.3 Strategic Thrust Areas and Next Steps in the Coordinated WIST Effort................... 1-23

2. Needs Identification and Validation Process .................................................................................2-1

2.0 Strategy.................................................................................................................................. 2-1

2.1 First WIST Symposium......................................................................................................... 2-1

2.2 Initial Information Gathering ................................................................................................ 2-3

2.3 Follow-up Survey .................................................................................................................. 2-3

2.4 Data Extraction and Analysis for Summary WIST Needs Templates................................... 2-4

2.5 Validation and Verification of Sector-Specific WIST Needs Templates.............................. 2-9

2.6 Second WIST Symposium .................................................................................................... 2-9

2.7 Special-Case Needs Validation Process .............................................................................. 2-10

2.7.1 Long-Haul Railways Sector....................................................................................... 2-10

2.7.2 Pipeline System Sector .............................................................................................. 2-11

3. Organizations Participating in WIST Validation ........................................................................... 3-1

3.0 Overview ............................................................................................................................... 3-1
Weather Information for Surface Transportation

viii

3.1 Federal Entities...................................................................................................................... 3-1

3.1.1 Department of Transportation...................................................................................... 3-1

3.1.2 Department of Energy.................................................................................................. 3-5

3.1.3 Department of Defense ................................................................................................ 3-5

3.1.4 Department of Commerce and National Oceanic and Atmospheric Administration... 3-6

3.1.5 Department of the Interior ........................................................................................... 3-7

3.1.6 Department of Agriculture........................................................................................... 3-7

3.1.7 Other Federal Entities .................................................................................................. 3-8

3.2 State and Local Agencies ...................................................................................................... 3-9

3.2.1 State Departments of Transportation ......................................................................... 3-11

3.2.2 Rural and Urban Transit Authorities.......................................................................... 3-13

3.2.3 Public School Districts............................................................................................... 3-14

3.2.4 Regional Airports—Airport Ground Operations ....................................................... 3-14

4. WIST User Needs—Analysis and Conclusions............................................................................. 4-1

4.0 Overview ............................................................................................................................... 4-1

4.1 User Needs: General Conclusions from the WIST Study ..................................................... 4-1

4.1.1 Users Recognize the Value of Weather Information ................................................... 4-1

4.1.2 Users Want Information Tailored to Their Activities.................................................. 4-2

4.1.3 WIST Needs Cover a Variety of Weather Elements, User Activities, Thresholds

and Lead Times .............................................................................................................. 4-3

4.1.4 Users Differ in Their Knowledge of Weather Impacts and Awareness of

 WIST Sources................................................................................................................. 4-6

4.1.5 Significant Differences Exist Between and Within Transportation Sectors .............. 4-10

4.2 Introduction to Sector-Specific Analyses of Weather Impacts, Mitigation Actions,

 and Information Needs........................................................................................................ 4-11

4.3 Roadway Sector................................................................................................................... 4-12

4.3.1 Sector Activities......................................................................................................... 4-12

4.3.2 Analysis of Activity–Elements .................................................................................. 4-13

4.3.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-15

4.4 Long-Haul Railway Sector.................................................................................................. 4-19

4.4.1 Sector Activities......................................................................................................... 4-19

4.4.2 Analysis of Activity–Elements .................................................................................. 4-20

4.4.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-21

4.5 The U.S. Marine Transportation System............................................................................. 4-25

4.5.1 Sector Activities......................................................................................................... 4-25

4.5.2 Analysis of Activity–Elements .................................................................................. 4-26

4.5.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-27

4.6 Pipeline Systems Sector ...................................................................................................... 4-33

4.6.1 Sector Activities......................................................................................................... 4-34

4.6.2 Analysis of Activity–Elements .................................................................................. 4-34

4.6.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-35
Weather Information for Surface Transportation

ix

4.7 Rural and Urban Transit Sector........................................................................................... 4-40

4.7.1 Sector Activities......................................................................................................... 4-41

4.7.2 Analysis of Activity–Elements .................................................................................. 4-42

4.7.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-42

4.8 Airport Ground Operations..................................................................................................4-48

4.8.1 Sector Activities......................................................................................................... 4-49

4.8.2 Analysis of Activity–Elements .................................................................................. 4-49

4.8.3 Impacts and Mitigation Actions, by Weather Element Group................................... 4-50

4.9 Overarching Themes from the WIST Needs Identification and Validation Activity .......... 4-54

4.10 Summary: Meeting the Needs and Addressing the Concerns of WIST User

 Communities ...................................................................................................................... 4-58

5. WIST Strategic Thrust Areas......................................................................................................... 5-1

5.0 Introduction .......................................................................................................................... 5-1

5.1 Strategic Thrust Area 1: Identifying and Specifying Gaps in Coverage of WIST

User Needs............................................................................................................................ 5-1

5.1.1 Barriers and Challenges in Identifying Unmet WIST User Needs .............................. 5-1

5.1.2 Next Steps for Strategic Thrust Area 1 ........................................................................ 5-3

5.2 Strategic Thrust Area 2: Expanding Coordination Among WIST R&D Programs

and WIST Providers.............................................................................................................. 5-4

5.2.1 Barriers and Challenges to Expanded Coordination of WIST Efforts......................... 5-4

5.2.2 Next Steps for Strategic Thrust Area 2 ........................................................................ 5-5

5.3 Strategic Thrust Area 3: Clarifying and Defining Provider Roles and Responsibilities ....... 5-6

5.3.1 Barriers and Challenges to Clearly Defined Roles and Responsibilities ..................... 5-6

5.3.2 Next Steps for Data Standards and a National Data Collection System, ..................... 5-7

5.3.3 Next Steps for an Open Systems Approach for WIST................................................. 5-9

5.4 Strategic Thrust Area 4: Translating Research Results and New Technologies

into WIST Applications ...................................................................................................... 5-10

5.4.1 Highlights of Applied Research and New Technology with Near-Term

Payoffs for WIST Users ............................................................................................... 5-10

5.4.2 Challenges to Current Technological Capabilities and Understanding ..................... 5-12

5.4.3 Opportunities in Current and Emerging Technologies .............................................. 5-13

5.4.4 Next Steps for Strategic Thrust Area 4 ...................................................................... 5-18

5.5 Strategic Thrust Area 5: Providing the Fundamental Knowledge to Support

Future Technology Development and Application............................................................. 5-18

5.5.1 Highlights of Longer-Term Research Topics ............................................................ 5-19

5.5.2 Barriers and Challenges ............................................................................................. 5-20

5.5.3 Next Step for Strategic Thrust Area 5........................................................................ 5-20

5.6 Strategic Thrust Area 6: Expanding Outreach and Education............................................. 5-21

5.6.1 Barriers and Challenges in WIST Outreach............................................................... 5-21

5.6.2 Next Steps for Strategic Thrust Area 6 ...................................................................... 5-22
Weather Information for Surface Transportation

x

5.7 A Vision for Surface Transportation Weather in the Future ............................................... 5-22

References...................................................................................................................................... Ref-1

Appendices

A. Entities Participating in WIST Needs Identification and Validation

B. WIST Needs Templates by Sector

 B-1 Roadways.

B-1.1 Federal Highways

B-2 Long Haul Railways

B-3 Marine Transportation System

B-4 Pipeline Systems

 B-5 Rural and Urban Transit Systems

B-6 Airport Ground Operations

C. Abbreviations and Acronyms Listing

D. Glossary of Terms

E. Weather Research and Technology Development Required to Meet

 WIST User Needs

F. Federal Entities and Program Activities Relevant to WIST
Weather Information for Surface Transportation

xi

Figures

1-1 Major U.S. ports and waterways .........................................................................................................1-5

1-2 Major refined pipelines of the United States.......................................................................................1-6

1-3 Speed-flow curves for different weather conditions, assuming a free-flow speed of

120 km/hr ...........................................................................................................................................1-8

1-4 OFCM federal partners in defining weather information needs ........................................................1-21

1-5 OFCM infrastructure .........................................................................................................................1-22

2-1 Distribution of desired lead times, all sectors. ....................................................................................2-7

2-2 Spatial grid spacing desired by weather information users. ................................................................2-8

2-3 Railroad network of the United States. .............................................................................................2-11

3-1 NWS regions .....................................................................................................................................3-10

3-2 State and local entities participating in WIST needs validation .......................................................3-10

4-1 Activity–element combinations by sector ...........................................................................................4-4

4-2 Distribution of activity–elements by sector.........................................................................................4-4

4-3 Distribution of lead time categories (Table 4-1) by transportation sector ...........................................4-5

4-4 Bimodal lead time distribution ............................................................................................................4-6

4-5 Sources of weather information reported by respondents ...................................................................4-8

4-6 Roadway activity–elements by weather group..................................................................................4-14

4-7 Railway activity–elements by weather group....................................................................................4-20

4-8 MTS activity–elements by weather group.........................................................................................4-26

4-9 Pipeline systems activity–elements by weather group. ....................................................................4-35

4-10 Transit activity–elements by group. .................................................................................................4-42

4-11 Airport ground operations activity–elements by weather group. .....................................................4-50

5-1 WIST users in each of the transportation sectors. ..............................................................................5-5

F-1 PMA regions .....................................................................................................................................F-13
Weather Information for Surface Transportation

xii

Tables

1-1 Weather Condition at Time of Vehicle Crashes..................................................................................1-4

1-2 Adverse Weather and Deaths by Vehicle Type ..................................................................................1-4

1-3 Federal Budget for Meteorology, Fiscal Year 2003 ..........................................................................1-19

2-1 Weather Elements Identified by WIST Users, Grouped by General Category ...................................2-5

2-2 Participating Users and Entities...........................................................................................................2-9

3-1 Federal Agency Responsibilities and Interests by Transportation Sector ...........................................3-2

4-1 Lead Time Categories .........................................................................................................................4-5

4-2 Roadway Activity Groups.................................................................................................................4-13

4-3 Long-Haul Railway Activities...........................................................................................................4-20

4-4 MTS Sector Activities.......................................................................................................................4-26

4-5 Sector Activities for Pipeline Systems Sector ...................................................................................4-34

4-6 Sector Activities for Rural and Urban Transit Operations ................................................................4-41

4-7 Sector Activities for Airport Ground Operations ..............................................................................4-49

4-8 Activity-Elements with Safety Impacts, by Sector............................................................................4-55

F-1 Interests of DOT Constituencies in Transportation Sectors ................................................................F-3

F-2 Interests of DOE Constituencies in Transportation Sectors ..............................................................F-12

F-3 Interests of DoD Constituencies in Transportation Sectors...............................................................F-15

F-4 Interests of DOC Constituencies in Transportation Sectors ..............................................................F-19

F-5 Interests of DOI Constituencies in Transportation Sectors ...............................................................F-22

F-6 Interests of USDA Constituencies in Transportation Sectors............................................................F-24

F-7 Interests in WIST Transportation Sectors of Constituencies for Other Federal Entities...................F-26
ES-1

Executive Summary

In 1998, a federal interagency committee identified the weather information needs of surface

transportation sectors (including ground and marine transportation systems) as a priority for

coordinated action. In response, the Office of the Federal Coordinator for Meteorological

Services and Supporting Research undertook a study of existing and potential needs for weather

information for surface transportation (WIST).

This report presents a compilation of these

needs and analyzes them in the context of

interests and concerns expressed in two

symposia on WIST, plus many smaller

meetings and interviews. Its purposes are

first, to make the compiled needs accessible

to the many audiences with an interest in

WIST, and second, to suggest next steps in

a coordinated WIST initiative. To achieve

the second purpose, the report draws some

general conclusions about WIST needs that

cut across the six transportation sectors

included in the study. It relates these

conclusions to overarching themes present

in the current transportation environment

(Chapter 1) and confirmed by the compiled

WIST user needs. These conclusions

Surface Transportation Sectors

This report covers six transportation sectors:

Roadway—state and federal highways, roads, and streets

Long-Haul Railway—rail lines providing intercity freight

and passenger service, with their yards, stations, and depots

Marine Transportation System—coastal and inland

waterways, ports and harbors, and the intermodal terminals

serving them

Rural and Urban Transit—bus and van service on streets

and roadways, rail lines for metropolitan subway and

surface “light rail” systems

Pipeline Systems—Above and below ground pipelines for

commodities such as crude oil, refined petroleum products,

and natural gas, plus the storage, transfer, and pumping

facilities for pipelines

Airport Ground Operations—All ground movement of

vehicles, work crews, and passengers.

Weather can increase safety risks and economic costs, while disrupting the efficiency of systems in every surface transportation sector. Among

the threats are (left to right) wing icing on planes before takeoff, hurricane flood damage to railbeds, ice on waterways, and winter weather on

highways.

Copyright AP Wide World Photos

Courtesy WRC-TV, copyright 2002

Copyright AP Wide World Photos

OFCM photo library
ES-2

provide the basis for suggesting next steps in each of six strategic thrust areas for continuing the

WIST initiative.

Why We Should Be Concerned About Transportation Weather

The effects of weather on the nation’s surface transportation systems touch our lives every day.

Weather affects the safety, efficiency, and economic productivity of our transportation systems

and facilities. According to a National Highway Traffic Safety Administration estimate, 7,000

fatalities and 800,000 injuries each year involve weather-related adverse road conditions as a

factor. The Coast Guard attributes 7 percent of recreational boating accidents to weather.

Weather has daily impacts on the goods carried by the nation’s Marine Transportation System

and its intermodal connections to rail, motor carrier, pipeline, and air cargo transportation

systems. These impacts affect the transit time, delivery reliability, efficiency, and cost of all

goods transported by these systems.

Meeting WIST Needs—The Time Is Right!

We cannot control the weather or its effects on vital

transportation systems. What we can do is use

information about the weather more effectively in

managing the operation of transportation systems.

We can mitigate or avoid the negative consequences

of adverse weather for users of those systems, while

getting the most value from benign weather

conditions. Fortunately, the immense advances made

in meteorological and environmental sciences,

coupled with the twin technological revolutions in

computing and digital-based communications,

provide us with powerful new tools for delivering

weather information to potential users across the

surface transportation sectors.

As an example, forecast-activated anti-icing pretreatment has been tested on a 29-mile length of

Idaho highway that is frequently icy in winter. The test resulted in a 62 percent reduction in road

maintenance labor hours, an 83 percent reduction in abrasives used to improve traction, and an

83 percent decrease in crashes. A road weather service system in Finland for both road

maintenance personnel and road users has an estimated cost–benefit ratio of approximately 1 to 5

for snow and ice control.

As these examples show, the answer lies not simply in providing more and more data; the

information conveyed by the data must be useful. It must be timely and accurate enough for

decision makers to rely on it when each decision can be costly in terms of both safety and

economic consequences. These requirements merge in two key challenges to be met by current

and emerging capabilities for delivering WIST to users:

• WIST is for decision support. Transportation system managers, infrastructure

operators and maintenance personnel, vehicle operators, shippers, and travelers—the

Costs of Roadway Weather

Adverse weather is estimated to play a role,

directly or indirectly, in 800,000 injuries and

7,000 fatalities annually resulting from vehicle

crashes. This represents about 28 percent of all

highway crashes and 19 percent of all fatalities.

The estimated annual economic cost, just from

weather-related crashes (deaths, injuries and

property), amounts to nearly $42 billion. A

study of the effects of snow, ice, and fog

estimated that these weather conditions caused

544 million vehicle-hours of delay on highways

in 1999.
ES-3

entire gamut of potential WIST users—need WIST as one factor in often complex

decisions about their actions.

• WIST users have diverse needs. Because the kinds of transportation-related

decisions made by WIST users differ, as do the circumstances in which decisions must

be made, the information content and its attributes vary from user to user.

Identifying and Validating WIST Users’ Needs

This report presents a compilation of needs for weather information that have been expressed by,

and validated by, existing and potential users of that information from the affected surface

transportation communities. Representatives from those communities were asked:

• Which specific weather elements (a weather event or

a condition affected by the weather or related

environmental factors) can affect their activities?

• What information about those weather elements

(spatial scale, thresholds of severity or proximity

important to decisions, timing of onset and duration)

would help the operators and users of those

transportation systems to ameliorate negative

consequences and exploit positive consequences?

• When is the information needed (the lead time of forecasts or the currency of

observations) to be most effective in supporting the decision processes of transportation

system managers, travelers, and others who decide on transportation activities?

Appendix A identifies the entities from the public and private sectors that participated by

providing answers to the above questions through an initial questionnaire and a more detailed

follow-up survey. The data provided by these information users on their existing and potential

needs for WIST were compiled as a set of WIST Needs Templates, which constitute Appendix

B. The draft template for each transportation sector was validated with many of these same

information users. Their comments were used to produce the final set of templates included with

this report and incorporated in the report’s analyses and conclusions.

Cross-Sector Conclusions from Analysis of WIST User Needs

The analyses of the compiled WIST needs (discussed in Chapter 4), together with the detailed

discussions with WIST users during the WIST symposia and the template validation process,

support five conclusions that apply to all six of the transportation sectors for which user needs

were identified.

Conclusion 1. Users recognize the value of weather

information.

During the WIST needs study, decision makers, regulators, and

operators across the spectrum of transportation activities

confirmed the value of appropriate weather information for

This report presents weather information

needs expressed and validated by

existing and potential information users

from surface transportation communities. These user-derived information

needs are compiled in the WIST Needs

Templates in Appendix B.

In a 2002 survey of potential users

of “511” traveler advisory

services, road weather and road

surface conditions were most

frequently identified as the most

critical component for this service.
ES-4

improving safety and enhancing the efficiency and effectiveness of their activities. Highway

maintenance managers concerned about freezing precipitation, pipeline operators worried about

hurricane-induced tidal surge, and vessel captains concerned about keel clearance in shallow

water must take actions whose consequences depend critically on accurate and timely

knowledge of weather and related conditions. The value of accurate and timely weather

information is well recognized throughout the surface transportation user community.

Conclusion 2. Users want information tailored to their activities.

In every transportation sector, users stressed the importance of getting weather information

tailored for the activity or decision-making process for which they are responsible. They want

detailed, location-specific forecasts and situation reports. They also need multiple ways of

getting the information—from radio and television, the Internet and other electronic data links,

and other communications media. Repeatedly, users stated needs for information that is much

more precise, focused, and relevant to their operations. They want higher resolutions, both

spatial and temporal. At the same time, they demand better accuracy in the forecasts.

Conclusion 3. WIST needs cover a variety of weather elements, user activities, thresholds,

and lead times.

The WIST needs validated by the surface transportation user communities encompass many

diverse weather elements, including a range of important environmental conditions that depend

on “the weather” as commonly understood but that are not viewed as meteorological parameters.

Examples include ground surface and

rail temperatures, wave height and tidal

predictions, and air quality. The WIST

needs also cover a broad range of

desired lead times and action

thresholds for various user activities

within each transportation sector.

Conclusion 4. Users differ in their

knowledge of weather impacts and

awareness of WIST sources.

Within each transportation sector, there

were users with a clear understanding

of how information on weather and

weather-related conditions could make

a difference in the efficiency and

effectiveness of their operations, as

well as users with lesser degrees of

awareness. The latter category of users

knew how the weather affected their

operations; they just had not considered how better information about the weather would be

useful. In many instances, once users had an opportunity to discuss the subject, they quickly saw

how timely and more accurate weather information could be of benefit.

Trackwalkers inspect a transit line track switch for warped rails on a

hot day in Massachusetts. Copyright AP Wide World Photos.
ES-5

Users also varied widely in their knowledge of what weather information was available and

where they could get it (information sources). Education of potential WIST users, including

interactions between the users and providers of weather information, must be part of the WIST

service delivery process. Providers must also understand users’ decision contexts and provide

information that supports the real-life decisions to be made.

Conclusion 5. Significant differences exist between and within transportation sectors.

The user groups that participated in the WIST needs study come from across the nation; they

represent the full geographic and climatic spectrum of the United States. Consequently, there is

significant variation in specification of WIST needs, both between the transportation sectors and

within a sector. These variations affect which weather elements are important and the thresholds

at which the user needs information to make key decisions. Chapter 4 includes a sector-by-sector

analysis of what users reported about the impacts of weather elements on their activities and the

mitigating actions they could take.

Goals and Next Steps for WIST Strategic Thrust Areas

Chapter 5 defines one or more goals in each of six strategic thrust areas for continuing a

coordinated WIST initiative. Next steps are suggested to move toward these goals.

Strategic Thrust Area 1: Identifying and Specifying the Gaps in Coverage of WIST User

Needs

The first strategic thrust area for continuing the WIST effort is to determine where there are gaps

in coverage of WIST user needs and how a diverse provider community—comprising both

public and private sector providers—can address them. A joint effort is needed to determine

which needs are not fully met and how the resulting gaps should be addressed.

Goal for Identifying Gaps in Coverage of WIST Needs. Identify validated user needs for

surface transportation weather information that cannot be met with existing information

resources of the public–private provider community. Determine whether technology

development in progress will meet the need or if additional technical development and/or

research is needed.

Next Step 1A. Establish a task force to:

• Ascertain (1) which WIST user needs in the initial baseline compilation are fully met

now, (2) which could be met more fully through improved presentation and

interpretation of current observational and forecast data, and (3) which require data

that are not yet available or that have attributes (e.g., accuracy, spatial and temporal

scale, timeliness) beyond what is now available

• Review and sustain or adjust priorities for research programs and for transitioning

promising tools and other technologies into operations
ES-6

• Support agency processes to validate and update user needs and provider community

programs and approaches for addressing them.

Next Step 1B. Sustain and expand the dialogue between the meteorological community as

information providers and surface transportation communities as information users.

Next Step 1C. Use the baseline of WIST needs represented by the templates developed

during this study as a work in progress, to be refined, extended, updated, and validated by

the participants in a continuing assessment of where capabilities can be delivered that fill

an identified gap or enhance value.

Strategic Thrust Area 2: Expanding Coordination Among WIST R&D Programs and

WIST Providers

To accelerate the application and use of new or emerging technologies and capabilities for WIST

support, technology transfer processes (concepts, capabilities, practices, and tools) linking the

government and private sectors need to be enhanced. Work to be done in this area includes more,

and better, coordination and agreement among federal, state, and local governments and the

private sector on the provision of data and services. The guiding principle for expanded

coordination and partnering must be to transfer the results of research and development (R&D)

programs, typically funded with federal support, to whichever entities are most capable of

implementing effective and efficient delivery of WIST services and products to the users.

Goal for Coordinating R&D and Technology Transfer. Expand and improve the coordination

and communication among both WIST-relevant R&D programs and field implementation

programs and projects aimed at incorporating WIST elements in the decision processes and

decision support systems used by transportation activities in all sectors. New and expanded

partnerships among government entities, the private sector, the academic R&D community, and

public-private entities for provision of WIST services and products should aim at increasing the

efficiency and effectiveness of translating R&D results into operational value for WIST users.

Traffic advisory signs, like this one

in Atlanta, represent an initial step

toward intelligent transportation

systems with route weather

information. Copyright AP Wide

World Photos.
ES-7

Next Step 2A. Coordinate the WIST-related R&D research efforts and technology transfer

programs of federal agencies, including but not limited to the U.S. Weather Research

Program, the national Intelligent Transportation Systems research efforts, and a WIST

R&D Program as proposed in this report. Transfer of research results and technology

demonstrations to operational capabilities, services, and products available to WIST

users should be a major component of this expanded coordination effort.

Next Step 2B. Prepare for and form strategic partnerships and alliances among government

entities (federal, state, and regional/local), the private sector, the academic R&D

community, and public-private entities.

Next Step 2C. To provide the legislative basis and funding support for expanded

coordination, the provider communities, with the support of the WIST user communities,

should give immediate attention to:

• Reauthorization of the U.S. Department of Transportation surface transportation

program under the Transportation Equity Act for the 21st Century (TEA-21).

• Full support for the Marine Transportation System as proposed by the Marine

Transportation System National Advisory Council and the Interagency Committee for

the Marine Transportation System.

Strategic Thrust Area 3: Clarifying and Defining Provider Roles and Responsibilities

The primary roles in providing weather information for surface transportation are shared among

a diverse array of partners in the public and private sectors. In the public sector are federal

entities and a large number of state and local government activities. In the private sector,

commercial entities sell value-added meteorological services and products. An even larger set of

commercial entities provides general information and communication products or services, in

which WIST is now or could be incorporated. Partnerships and alliances are critical in this

environment, where thousands of entities have roles in developing, maintaining, and operating

the nation’s transportation system.

A significant barrier to improving the products and services available to WIST users is that the

roles of federal entities versus those of state and local governments or the private sector are

neither clear nor consistent. Continued cooperative efforts by all parties in the WIST provider

community will be necessary to resolve these conflicts and fill gaps in the service, guidance, and

regulatory structures that influence delivery of weather information to WIST user communities.

Explicit policy guidance on the roles and responsibilities of public and private sector participants

in providing and tailoring weather information would provide a solid basis for expediting

provision of new and improved products and services to WIST user communities.

Data Standards and a National Data Collection System. The means of generating, obtaining,

transferring, and applying weather information are not standardized at present. This lack of

standards significantly hinders dissemination and application. Nonstandard or erratic updates to

observations and forecasts undermine the value of weather information for transportation-related

decision processes and systems.
ES-8

A nationwide collection of local weather data does not exist and has not been mandated. These

data are usually of greatest value locally, but ideally they should then be passed to a national

collection location, where the data can be subjected to quality controls, aggregated, synthesized,

and archived. The Cooperative Observer Network, operated by the National Oceanic and

Atmospheric Administration’s National Weather Service (NWS), is a nationwide weather and

climate observing network that, when modernized, will provide a useful framework for more

extensive national collection and integration of weather and environmental data from regional

mesonets.

Goal for Data Standards. Provide guidance on the roles and responsibilities of the public and

private sectors for various types of observations and networks, particularly in light of better

understanding of the accuracy needed to support the nontraditional weather/environmental

elements and the new higher-resolution observation and modeling products required by WIST

users.

Goal for Nationwide Data Collection. Integrate proliferating surface weather observations and

networks and incorporate their data into a nationwide data system. This data system should

provide access to related geophysical data of value to surface transportation operations. This

effort should address:

• Equipment (measurement/sensor adequacy and

accuracy, siting criteria, calibration, metadata, and

legacy systems)

• Communications protocols and standards

• Data standards for quality control, accessibility,

compatibility, interoperability, and archiving.

Next Step 3A. Determine the roles of NWS and/or other

public and private sector partners in pursuing the

above goal for nationwide data collection.

Next Step 3B. Address issues of observation standards

and protocols, equipment siting, data collection,

processing, archiving, access, and proprietary data

through the use of a task force or similar action group.

Next Step 3C. Examine, test, and implement

operationally current and emerging technologies for

system definition and transition, system optimization,

modal optimization, and environmental considerations.

Value of an Open Systems Approach for WIST. A WIST information network will have many

providers of services and products and will serve a diverse community of consumers. For this

network, there are technical advantages to open systems architectures for communications and

interfaces. Decision support tools can be implemented as an application layer on top of this open-

 The National Weather Service maintains

automated surface observation systems,

like this one, at airports and other

locations across the nation. Local and

regional mesonets provide more detailed

coverage over limited areas. Courtesy

NWS, Medford, Oregon.
ES-9

systems foundation. The national Intelligent Transportation System (ITS) architecture can

provide a starting point for discussing technical issues of data management and accessibility (e.g.

format standards) for WIST communications. There must also be attention to security issues,

including protecting the integrity of shared data resources and managing the risk that open

information will be used in hostile actions.

Goal for Open Systems in WIST Communications. Resolve the technical aspects of providing

open access to weather information in a manner that benefits diverse WIST users fairly, while

providing commercial or mixed public-private value-added suppliers with a level playing field

and reasonable incentives for participating. Address issues of data system security.

Next Step 3D. Work toward full compatibility of transportation-related communications

and information systems with the national Intelligent Transportation Systems

architecture.

Next Step 3E. Establish a task force to develop a security strategy for national weather

information networks, addressing issues of data integrity and the balance between

open access to data and restrictions to avoid hostile use of data systems and resources.

Strategic Thrust Area 4: Translating Research Results and New Technologies into WIST

Applications

A number of currently unmet WIST user needs can be met in the near term (within 5 years)

through applied research or development of technology applications. Some of these technologies

incorporate advances in observing or forecasting meteorological parameters, others involve

weather-affected conditions, such as black ice on highways or railbed ground heave. Still others

involve information technology and software to make WIST data easier to incorporate and apply

in users’ decision processes. For these areas, translating research results and science into

practical information for users is the primary objective.

Decision support systems will need to incorporate techniques for working with the predictive

uncertainty inherent in high-resolution forecasting at longer lead times. For a number of

Icy conditions after a March 9,

2002 storm in Nebraska caused

this trailer truck to jackknife on

Interstate 80. Technology is now

available to detect black ice that

drivers cannot see. Copyright AP

Wide World Photos.
ES-10

activities in the surface transportation sectors, an accurate forecast of favorable weather is often

just as important as a forecast of adverse or mission-limiting weather.

There are significant near-term opportunities to translate technology advances into operations

supporting the Marine Transportation System. One key to reducing risks while increasing

efficiency in this vital transportation system is to invest in the information infrastructure that

supports it. This infrastructure includes weather predictions and forecast models that use both

meteorological and oceanographic data to forecast conditions for navigation.

The U.S. Weather Research Program, a partnership of federal entities with the academic and

commercial communities, plays a key role in providing the fundamental knowledge and

application development that feed the ongoing stream of new meteorological technology from

the modernization of the National Weather Service. This research program has substantial value

as an umbrella program through which all federal entities with weather-relevant program

objectives contribute resources to a coordinated R&D effort. However, the limited portfolio of

the U.S. Weather Research Program, together with its emphasis on research rather than

operational implementation, constrains its capability to serve all the WIST R&D needs of federal

agencies. The range of R&D required, and particularly the specificity of applications tailored to

the needs of the surface transportation communities, argues for a separate WIST R&D program.

This program would address issues relevant to weather impacts on surface transportation (all

sectors) and to improving the capability to move meteorological and other weather-related

information into users’ decision processes.

R&D programs under a number of federal departments and agencies also provide technology for

various surface transportation communities. Greater coordination of the R&D effort across these

intramural programs, in conjunction with an interagency WIST R&D Program, would leverage

the federal investment in improving and expanding WIST. Cooperative planning and

participation by all levels of government, the university research community, and the private

sector can leverage the investments made in research to obtain the greatest benefit for and from

the transportation systems of the future. The WIST R&D Program should include mechanisms

for transitioning research results and new technology into WIST applications. Special attention

should be given to leveraging research that has linkages, synergy, or applications in other high

priority programs such as homeland security.

Goal for Translating R&D into WIST Applications. Establish a WIST R&D Program. This

program should be coordinated with and complement the U.S. Weather Research Program, as

well as other R&D programs in transportation weather, including work in progress, planned, or

funded by federal entities, state and local public sector entities, universities, or private sector

organizations.

Next Step 4A. Users and providers need access to information about the technology

developments and research initiatives relevant to their WIST needs.

• This information must be structured and presented in ways that allow users to

understand how they can best exploit available and emerging technology and

information resources.
ES-11

• Access to the information can be facilitated through interdepartmental

cooperation at the federal level, coupled with strategic partnerships and alliances

within and among the weather information provider communities of the public

and private sectors.

Next Step 4B. The federal partners in the Federal Committee for Meteorological Services

and Supporting Research (FCMSSR) should propose a significant, cohesive research and

development program that will provide the basis for improved, integrated weather

information, tailored to supporting users’ decision processes across all surface

transportation sectors and activities.

Strategic Thrust Area 5: Providing the Fundamental Knowledge to Support Future

Technology Development and Application

There are areas in which our fundamental knowledge of weather phenomena is too limited to

provide all the information WIST users need, when they need it. If these needs are to be met,

fundamental research is needed that is oriented toward filling in the gaps in what we know. Over

the next decade, additional and substantial benefits to the nation, in terms of safety, reduced

economic losses, and increased productivity, are possible with (1) better spatial and temporal

resolution in both forecasts and observations and (2) better forecast accuracy.

The spatial and temporal resolution of weather information needed for surface transportation

applications in general and for decision support systems in particular is typically in the misoscale

horizontally (grid spacing of 40 meters to 4 km) and in a very shallow layer vertically (from

ground level to about 2 meters above it). To meet operational time lines, updates must be rapid—

on a scale of minutes to hours—and coupled with lead times of 48 hours. These spatial and

temporal requirements present formidable scientific challenges. Meeting them will require

improved understanding in areas such as boundary layer meteorology, misoscale

thermodynamics, the effects of small local variations, probability and statistics, high-resolution

numerical modeling that includes land-air-water interactions, the verification and quality control

of nonstandard data, and the preparation and communication of probabilistic forecasts.

Processing data at these finer scales will require expanded computational capabilities.

Goal for Providing the Fundamental Knowledge Base. Identify and support fundamental

research representing a longer-term investment in acquiring the knowledge base needed to meet

important WIST user needs that cannot be fully satisfied on the basis of current knowledge.

Next Step 5a. Include in the coordinated R&D programs for WIST a substantial level of

fundamental research with strategic potential for expanding the fundamental

knowledge needed to meet WIST users’ needs.

Next Step 5b. The federal agency partners in the FCMSSR should present a unified

rationale to Congress and the Administration for the strategic potential of the

fundamental research topics included in the WIST R&D Program and other

coordinated R&D programs, similar to what has been done in the past for the U.S.

Global Change Program.
ES-12

Strategic Thrust Area 6. Expanding Outreach and Education

There are major cultural differences between the meteorology and transportation disciplines.

Users need assistance and training to achieve maximum benefit from applications of weather

information. To help with educating WIST users, universities can offer surface transportation

weather courses in programs for transportation management degrees. Training programs for

users and managers of transportation systems that provide emphasis on weather factors and the

use of weather information will benefit the transportation industry and its consumers.

At the same time, those with training in the meteorological and environmental sciences, as well

as expertise in the technologies and techniques of observing and forecasting weather and related

phenomena of concern to WIST users, must do better at communicating the significance of their

knowledge and technology to the users. Courses in both degree programs and continuing

education programs will help meteorologists and other scientific specialists understand surface

transportation systems and management processes. This formal training in the conceptual

frameworks, operational environments, and technical systems within which transportation

decision makers work can be coupled with direct experience working with the user communities.

As traveler-oriented weather information services evolve, the general public needs to be

informed about them. Broad support for WIST initiatives can be fostered by communicating the

values of WIST, in improving both transportation safety and economic efficiency, beyond just

transportation system managers and operators.

Goals for WIST Outreach and Education. (1) Incorporate mechanisms for education of

potential WIST users, including interactions between the users and providers of weather

information, in WIST service delivery processes. Include current information on WIST

applications and the value of WIST in transportation systems operations in the training for

surface transportation professionals. (2) Provide and promote educational opportunities for

meteorologists and related professionals to learn about surface transportation systems where

weather and related environmental information can improve system performance. (3) Include

information about WIST applications and ways that the public can access and use WIST in their

Hands-on training with state-of-theart meteorological information

systems is part of this course

conducted by the Cooperative

Program for Operational

Meteorology, Education, and

Training (COMET), funded by the

NOAA National Weather Service.

Photo courtesy COMET and NOAA.
ES-13

own transportation activities in “weather education” outreach to the general public and in school

weather education programs.

Next Step 6. Conduct a WIST Education Forum on the status of, and directions for

expanded efforts in, education, training, and outreach for delivery of services and

products to meet WIST user needs. There should be broad participation from the

provider and user communities, as well as from the FCMSSR partners. Include topics

on:

• Mechanisms for education of WIST users

• Opportunities for meteorologists and related professionals to learn about surface

transportation systems

• Outreach to the general public through the media and school programs.
1-1

Chapter 1

Introduction and Background

1.0 Introduction

This report provides a compilation of users’ needs

for weather information—needs that have been

validated with user communities in six surface

transportation sectors. Based on an analysis of these

needs, the report identifies strategic thrust areas for

improving and expanding the weather information

currently available. It suggests next steps in these

areas that will enhance the value of weather

information to the safety, efficiency, and

effectiveness of the nation’s surface transportation

systems.

For this report, needs are defined as weather

data that provide important elements of

information for the decision-making processes

used by travelers, operators, or managers

involved in any surface transportation activity

(the users). A weather information need is

characterized by a weather element, the

transportation activity that requires the

information, the threshold at which the activity

needs information about that element, and the

lead time required for effective planning or

action.

The nation’s surface transportation sectors include (from upper left) rural and urban transit systems, long-haul railroads, the

Marine Transportation System, pipeline systems, and airport ground operations.

Copyright AP Wide World Photos

Copyright AP Wide World Photos

Copyright AP Wide World Photos

Courtesy Office of Pipeline Safety,

Department of Transportation

Copyright AP Wide World Photos
1-2

This chapter highlights some of the important impacts of weather on the nation’s surface

transportation systems and summarizes some of the existing and emerging capabilities for

providing weather information for surface transportation (WIST) to users. Chapter 2 describes

the process by which users’ needs for WIST were identified and validated by developing a set of

WIST Needs Templates. The final version of these templates is included as Appendix B.

Chapter 3 summarizes the interests in WIST of the federal, state, and local organizations that

participated in developing and validating the templates. Each template covers one of the six

transportation sectors: roadways, long-haul railways, the Marine Transportation System (MTS),

pipeline systems, rural and urban transit, and airport ground operations (see textbox below).

Chapter 4 provides a high-level view of the data in the WIST Needs Templates, along with

background information—gathered from the user communities during development of the

templates—that helps in interpreting the template data. Users throughout the surface

transportation communities surveyed for this study need accurate weather information beyond

what is currently available. From highway maintenance managers concerned about freezing

precipitation to pipeline operators worried

about hurricane-induced tidal surge to

river barge captains concerned about

reduced visibility in fog, users, decision

makers, and regulators across the spectrum

of transportation activities confirmed the

value of weather information in

improving safety and enhancing the

efficiency and effectiveness of their

activities.

The economic impact of weather on

transportation systems, its toll on the

safety and health of the public using these

systems, and the increasing demands that

will stress system capacity, environmental

quality, and social equity dictate that

actions be taken to resolve the myriad

weather-related transportation issues

facing our nation. These factors are

reflected in the conclusions from the WIST

needs analysis, presented in Chapter 4.

Chapter 5 suggests the next steps to be taken in six strategic thrust areas for continuing the

coordination of research and development (R&D) programs and for translating research results

and new technology into products and services to meet WIST users’ needs. Chapter 5 also

presents a summary vision of future weather information systems for surface transportation, if

users’ WIST needs are recognized and met.

Transportation Sectors Versus Modes

For this report, the term mode best describes a narrower,

more specific form of transportation, such as automobile,

bus, truck, ferry or subway train. The term sector is broader

in scope and encompasses multiple modes that share a

major characteristic, such as the medium in which they

operate (on water, on roads, on railways, in the air, etc.) or

operation under one management (e.g., transit authorities).

This report covers six transportation sectors:

Roadway—state and federal highways, roads, and streets

Long-Haul Railway—rail lines providing intercity freight

and passenger service, with their yards, stations, and depots

Marine Transportation System (MTS)—coastal and

inland waterways, ports and harbors, and the intermodal

terminals serving them

Rural and Urban Transit—bus and van service on streets

and roadways, rail lines for metropolitan subway and

surface “light rail” systems

Pipeline Systems—Above and below ground pipelines for

commodities such as crude oil, refined petroleum products,

and natural gas, plus the storage, transfer, and pumping

facilities for pipelines

Airport Ground Operations—All ground movement of

vehicles, work crews, and passengers.
1-3

Road Weather Bottom Line:

7,000 fatalities

800,000 injured

$42 billion in economic costs

—each year

Source: NHTSA estimate

(Lombardo 2000).

1.1 Why Should We Be Concerned?

The nation's surface transportation systems touch our lives many times each day. They connect

consumers with resources and enable us to travel where we need or desire to go. Nearly every

citizen uses or relies on these systems daily—including the 3.9 million miles of public roads, 2

million miles of oil and natural gas pipelines, 120,000 miles of major railroads, and over 25,000

miles of commercially navigable waterways. Transportation services are provided at 5,400

airports, throughout the 6,200 miles of urban rail transit, and at 3,750 waterport terminals

(FHWA 1998, p. 17; DOT 1999; TRB 2001). The total value of the national transportation

infrastructure is $1.5 trillion, and 11 percent of the national gross domestic product (GDP), or

about $8 trillion, is related to transportation (TRB 2001, FHWA 2002a). Weather influences

virtually every type of operation or activity involved in these transportation systems and

facilities.

The scale of use of surface transportation systems in the United States is impressive. More than

200 million cars and light trucks use our highways. Commuters number about 115 million, and

34 million of them travel more than 45 minutes each way. Of the more than 9 million recreation

vehicles, 1.1 million are on the road at any given time. Of the more than 3 million truckers, about

1.1 million are long-distance haulers. Rental cars number about 1.6 million (TRB 2001, FHWA

2002a). On the nation’s waterways, ferryboats carry about 134 million passengers each year,

while about 78 million people annually engage in recreational boating. In addition, cruise ships

provide service to 5 million passengers every year (DOT 1999).

Parts of our surface transportation system function at or near their maximum capacity much of

the time, and capacity utilization is increasing. All surface transportation modes have congestion

at critical bottlenecks. Weather reduces the capacity throughout the system, creating new

bottlenecks and exacerbating existing ones. Actions that mitigate these weather effects improve

transportation system safety and efficiency.

1.1.1 Adverse Weather and the Nation’s Streets and Highways

In the United States about 41,000 people die on highway

systems each year. These deaths result from six million crashes

that also cause more than 3 million injuries annually.

According to the National Highway Traffic Safety

Administration (NHTSA), each year, on average, about 1.7

million of these vehicle crashes occur in adverse weather or

weather-related adverse road conditions.1

One estimate from NHTSA is that adverse weather and adverse road conditions related to

weather are directly or indirectly a factor in approximately 800,000 injuries and 7,000 fatalities

resulting from vehicular crashes. That represents about 28 percent of the total crashes and 19

 

1

 Uniform statistics on weather conditions as a factor in accidents are difficult to collect. NHTSA is working on

gathering reliable data on this important factor from state and local public safety authorities, but results were not

available for this report. The numbers cited here for weather-related injuries, fatalities, and costs are estimates

presented by a NHTSA official at the WIST II symposium.
1-4

percent of the total fatalities. The estimated annual economic cost from these weather-related

crashes (deaths, injuries, and property) amounts to nearly $42 billion (Lombardo 2000).

Table 1-1 shows the weather

condition present when vehicle

crashes caused injuries or death.

Table 1-2 compares, by vehicle

type, the deaths during adverse

weather with total roadway deaths.

Note that neither of these tables

includes weather-related adverse

road conditions, which may persist

after the weather clears. Nor does

the presence of adverse weather at

the time of a crash imply that

weather was a causal factor.

Safety and the economic

consequences of accidents are

certainly critical reasons for being

concerned about road weather—the impact on road and highway conditions of weather and

related phenomena. But they are not the only reasons. Rain, ice, snow, fog, and other adverse

weather conditions can directly reduce the effective capacity of roads and highways (Chin et al.

2002). Because of safety concerns and the consequences when an accident occurs, state and local

authorities may impose lower speed limits and partial or complete closures of streets, roads, and

highways. Or they may restrict the vehicles allowed to travel on them. Many effects of weather

on road conditions—for example, standing water after heavy downpours, roadbed weakening

from prolonged excessive soil moisture, potholes after the winter freeze-thaw season, fallen trees

and debris after strong storm winds—can continue to slow or halt normal traffic for hours, days,

and even weeks after the weather itself has turned fair.

Table 1-1 Weather Condition at Time of Vehicle Crashes (1999 Data)

Number of Crashes (percent total) Weather Injuries Deaths

 5,281,000 84% Normal 2,757,000 (85%) 37,107 (89%)

 679,000 11% Rain 364,000 (11%) 3,086 (7%)

 199,000 3% Snow/Sleet 63,000 (2%) 680 (2%)

 47,000 <1% Fog 18,000 (0.5%) 569 (1%)

 72,000 1% Other 34,000 (1%) 275 (<1%)

 6,279,000 100% All conditions 3,236,000 (100%) 41,717 (100%)

Source: Lombardo 2001.

Table 1-2 Adverse Weather and Deaths by Vehicle Type (1989–1999 Totals)

Vehicle Total Deaths

Adverse Weather

Present

Percent

of Total

Passenger Cars 312,620 42,585 13.6

Light Trucks 190,271 26,221 13.8

Large Trucks 56,278 9,346 16.6

Motorcycles 28,537 969 3.4

Buses 3,617 622 17.2

Source: Lombardo 2001.

Winter weather causes a pile-up on Interstate 95 in Virginia. Image

Courtesy of WRC-TV, copyright 2002.
1-5

In one year (1999), an estimated 544 million vehicle hours of delay occurred on freeways and

principal arterial roads, just from fog, snow, and icy conditions (Chin et al. 2002). State, city, and

county highway maintenance agencies spend $2.1 billion per year to treat snow and ice on

roadways—a third of which is spent just for treatment chemicals (FHWA 1998, p. 16; Davies et

al. 2001). The information gathered from transportation system decision makers for this study

suggests that these measurable costs represent merely the tip of an iceberg of total direct and

indirect economic costs incurred each year because of road weather.

1.1.2 Adverse Weather and Other Surface Transportation Sectors

Other surface transportation sectors are also affected by the weather, although the significant

weather conditions and consequences may differ from the more familiar effects on roads and

highways. For most of us, the MTS and the nation’s pipeline systems operate behind the scenes

of our everyday lives. Our road and rail systems are familiar sights, but most of us are unaware

of the extent to which daily commerce depends on waterways and pipelines, as well as on trucks

and trains. Figure 1-1 shows major ports and waterways of the MTS; Figure 1-2 shows just one

of the nationwide pipeline systems in the pipelines sector.

Major U.S. Ports and Waterways

Figure 1-1 Major U.S. ports and waterways. Source: U.S. Army Corps of Engineers
1-6

We are even less aware of the diverse ways that weather affects these essential transportation

sectors. Although these sectors—railroads, waterways and ports, airport ground operations, and

pipelines systems—have far fewer injuries and deaths than occur on roads and highways,

weather still affects safety and economic efficiency. The U.S. Coast Guard lists weather as the

cause of 7 percent of recreational boating accidents (DOT 1999, p. 41). Weather impacts in one

region have consequences that ripple through interconnected transportation networks, causing

bottlenecks, delays in delivery, and imbalances in supply and demand that lead to higher costs

for consumers.

Figure 1-2 Major refined petroleum product pipelines of the United States. See Section 4.6 for additional maps of

U.S. pipelines. Source: AOPL 2002.

The freight community views these transportation assets and infrastructure as an end-to-end

system. This systems viewpoint begins with the goods as they arrive at a port in the United States

aboard a ship; are transferred to truck, rail, or plane assets; and move to distribution centers or

retail centers. To be efficient, this intermodal system requires significant coordination among

many producers and shippers. As the practice of just-in-time delivery (the dependable delivery of

raw materials or goods so that a factory or retailer does not have to maintain a large inventory)

spreads through U.S. industry, shippers must plan for and cope with weather of all types and

severity.
1-7

The MTS offers a telling illustration of how these essential transportation systems can be

affected by weather. This system comprises the nation’s navigable waterways, ports, and

harbors, as well as the connections to railroad, roadway, and pipeline systems. It enabled the

United States to become the world’s leading maritime trading nation; over 95 percent of U.S.

foreign trade tonnage is shipped by sea (DOT 1999), and more than 38 percent of intercity

freight is carried on inland waterways and pipelines (Coyle et al. 2000). On February 27, 2001,

fog closed the Houston ship channel to inbound traffic, causing long delays for vessels using this

waterway. Similar conditions caused a backlog of almost 80 ships earlier in the month. Houston

and neighboring ports are home to the nation’s largest oil and petrochemical plants. Fog along

the Gulf Coast was cited as the main reason for a huge, 12 billion barrel decline in the output of

U.S. refineries that week. (Reuters 2001).

Another incident, this one involving an Amtrak passenger

train derailment, illustrates how weather conditions can

cause problems specific to a transportation system’s

infrastructure and operations. July 29, 2002, was an

excessively hot day in the Mid-Atlantic region. As the

Capitol Limited sped through Kensington, Maryland, the

engineer applied the train’s emergency brakes after

spotting an area of misshapen track ahead. The multiple

car derailment 45 seconds later left bleeding passengers

crawling out the windows of overturned cars. A total of

101 passengers were injured, with one still in serious

condition the next day. Experts considered the most likely cause of the 30-inch misalignment of

the welded track to be buckling due to the hot weather. A heat order issued that day had reduced

the posted speed for freight trains from 55 to 45 miles per hour (mph), but not the 70 mph speed

limit for passenger trains. The line remained closed to all traffic until the derailed cars could be

In October 1994, a major flood on the

San Jacinto River near Houston

undermined numerous pipelines. Eight

pipelines ruptured, igniting petroleum

spills into the river. More than 500

people suffered burn injuries. Effects of

weather phenomena are the second-most

frequent contributor to pipeline damage

or failure.

Source: NTSB 1996

Reduced visibility from fog slows traffic on the MTS.

Photo courtesy NOAA Photo Library.
1-8

removed and the damaged track replaced. Although the number of derailments due to heat

buckling of rails has declined, there were 44 accidents attributed to this weather-related condition

in 2001 (Manning 2002).

1.2 Exposures, Threats, and Risks are Increasing

The economic and safety impacts of adverse weather and weather-related road conditions on

highway carrying capacity will multiply as traffic approaches the effective carrying capacity of

the system (Figure 1-3). Since 1982, while the U.S. population grew just 20 percent, the time

Americans spend in traffic jumped an amazing 236 percent (U.S. News and World Report 2001).

In major American cities, the length of the combined morning–evening rush hours doubled, from

under three hours in 1982 to almost six hours today. The average driver now spends the

equivalent of nearly a full workweek each year stuck in traffic. Congestion costs Americans $78

billion a year in wasted fuel and lost time—up 39 percent since 1990. In Houston, traffic jams

cost commuters on the Southwest Freeway and West Loop 610 an average of $954 a year in

wasted fuel and time. In New Jersey's Somerset County, congestion costs the average licensed

driver $2,110 a year (U.S News and World Report 2001).

The Federal Highway Administration projects that, over the next 10 years, the number of

vehicle-miles traveled is estimated to increase by 24 percent. In 20 years, it is expected to

increase by 53 percent (FHWA 2002a). As more people and more freight travel more miles on

FIGURE 1-3 Speed-flow curves for different weather conditions, assuming a

free-flow speed of 120 km/h. As traffic density (flow rate) increases, adverse

weather has a greater impact on average vehicle speed. Pc = passenger car, ln =

lane.
1-9

the same streets and highways, adverse weather and weather-related road conditions will

increase the strain on the roadway system.

Travelers are certainly aware of the risks associated with road

weather. In March 2002, the Gallup Organization reported the

results of a public opinion survey on the information most

important to potential users of “511” traveler advisory

services. Reports on weather-related and road surface

conditions were most frequently identified as the most critical

component for a 511 service, ahead of accident and road

incident reports, construction updates, and even congestion

levels on freeways. Forty percent of the respondents identified

weather and road conditions as most critical (ITSA, 2002b).

To the extent that capacity-reducing weather variations can be anticipated and communicated,

and more precise mitigation measures can be implemented, system efficiency can be improved

while operating costs and the number of crashes can be reduced. A recent literature review found

no comprehensive studies of costs and benefits for an implemented road weather information

system (RWIS) in North America (Boon and Cluett 2002, p. 39). However, there are numerous

case studies of how limited RWIS deployments, combined with an anti-icing program, have

decreased costs and improved efficiencies for both road maintenance management and travelers.

The costs and benefits of forecast-activated anti-icing pretreatment have been studied on a 29-

mile stretch of U.S. Highway 12 in Idaho. This study showed a 62 percent reduction in road

maintenance labor hours, an 83 percent reduction in use of abrasives to improve traction, and an

83 percent decrease in accidents (Breene 2001). Case studies prepared for the FHWA’s

RoadSavers program include the following results reported by state and local highway agencies

using an RWIS (FHWA 2002c):

• In the first winter of using an RWIS in decisions on deploying crews for de-icing, the

Massachusetts Highway Department saved over $53,000, one-fourth from lower labor

costs and the rest from reduced use of equipment, salt, and sand.

• The West Virginia Parkways Authority installed four RWIS units along a 153-km stretch

of the West Virginia Parkway in 1989. The savings in salt use were estimated at $6,500

per storm, with labor savings of an additional $2,300 per storm.

• The Dallas, Lubbock, and Amarillo districts of the Texas Department of Transportation

installed RWIS stations beginning in 1990. Maintenance managers reported cost savings

in materials, equipment, and labor that paid for the installations after the first two or three

storms. The RWIS stations have also proved useful in scheduling construction work in

fair weather. The RWIS sensors are being evaluated for use in flash-flood warnings

during the summer thunderstorm season.

• The New Jersey Department of Transportation began installing RWIS stations in the

1980s and plans to build up to a system of 50 to 60 stations providing statewide coverage.

Savings in chemicals, labor, and equipment costs are estimated to reduce expenses for

snow and ice control by 10 to 20 percent or more, statewide.

Call “511” for Road Weather!

40% of potential users of 511 travel

advisory services identify road

weather and surface conditions as

the “most critical” component of

this growing transportation

information service.
1-10

A road weather service system in Finland for both road maintenance personnel and road users

has an estimated cost–benefit ratio of approximately 1 to 5 for snow and ice control (DOT 2002).

A 1 to 5 ratio of costs to benefits has also been estimated for full implementation of RWIS and

related operational efficiencies in Washington State (Boon and Cluett 2002, p. 39). Thus, a wellinformed "weather response" has a high economic payoff, as well as decreasing the risks to

persons, goods in transit, and transportation assets.

Risks from exposure to adverse weather conditions are increasing in other ways as well. Certain

elements of the population, such as those who are elderly, disabled, or have a low income, are

more severely affected by weather impacts on their modes of transportation than the average

citizen may be. In the 2000 census, persons 65 and older were 12.6 percent of the population.

The Census Bureau expects this fraction to rise to 20 percent by 2030 (Kinsella and Velkoff

2001, pp. 133-134). Many of the elderly rely on rural and urban transit systems, which are

subject to delays and cancellations in adverse weather. As a second example, the Census Bureau

reports that one fifth of all Americans and nearly half of all senior citizens over age 65 have

some level of disability (McNeil 1997). The routine of scheduled, accessible transit operations is

a key factor in enabling people with disabilities to find and accept employment and to participate

in other daily life activities. Because the number of people with disabilities is likely to increase

as the population ages, the total risk from adverse weather impacts on their modes of

transportation will increase.

A third example of increasing risks is the shipment of hazardous materials. Hazardous materials

are shipped via many modes of transportation in the roadway, rail, MTS, and airport ground

operations sectors covered in this study. If a release of hazardous materials occurs, atmospheric

transport and diffusion of hazardous substances becomes an immediate concern of the public

safety and emergency response teams involved. Major arteries may be closed, and populated

areas at risk of exposure may need to be evacuated quickly. The weather may or may not play a

role in causing a hazardous release. However, emergency response managers always need to

Richard Raczynski, Chief Engineer

for the New Jersey Turnpike, with

one of the RWIS stations installed

along that state’s highways.

Copyright AP Wide World Photos.
1-11

know how the weather will affect the dispersion of materials and their plans for containing the

damage and recovering.

1.3 MEETING WIST Needs—The Time is Right!

We cannot control the weather or its effects on vital transportation systems. What we can do is

use information about the weather and weather-related conditions to manage the operations of

our transportation systems more effectively, in preparing for and responding to whatever the

weather may bring. Fortunately, the immense advances made in meteorological and

environmental sciences, coupled with the twin technological revolutions in computing and

digital-based communications, provide us with powerful new tools for delivering weather

information to potential users across the surface transportation sectors.

However, the answer lies not simply in providing more and more data. The information

conveyed by the data must be useful. It must be timely and accurate enough for decision makers

to rely on it when their decisions can be costly in terms of both safety and economic

consequences. Just as important, the information must be readily assimilated into the decision

processes and procedures that potential WIST users already rely upon—or will use in the

future—to make their decisions, implement them operationally, and reassess those operations for

continuing correction and improvement. Two key challenges should be kept in mind when

assessing current and emerging capabilities for delivering WIST to users:

• WIST is for Decision Support. Transportation system managers, infrastructure

operators and maintenance personnel, vehicle operators, shippers, and travelers—the

entire gamut of potential WIST users—need WIST as one factor in often complex

decisions about their actions. Meeting those needs requires understanding how the

information could affect the user’s decision process: What information does the user

need? When is it needed? How accurate does it need to be to make a difference?

• WIST Users have Diverse Needs. Because the kinds of transportation-related decisions

made by WIST users differ, as do the circumstances in which decisions must be made,

the information content and its attributes vary from user to user. This report recognizes

the diversity of information needs by referring to multiple “user communities” even

within a transportation sector. At a general level, a weather map in the newspaper or the

weather report on the evening television news provide some useful information to many

of these communities. But the potential benefits of our scientific knowledge and

technological capabilities can only be realized by tailoring WIST at a much more detailed

level, across a broader spectrum of diverse user communities, than has ever before been

done.

Section 1.3.1 highlights some of the most promising tools to meet this challenge. Section 1.3.2

describes future opportunities that further research and development can provide. In Section

1.3.3, the current situation in coordinating technology implementation for WIST—with the R&D

to support it—is compared with the progress made in aviation weather during the past decade.
1-12

1.3.1 The Potential for Existing and Emerging Technology to Meet WIST

Needs

Collecting Observations and Preparing Forecasts

Many of our existing national science and technology assets can be applied to the challenges of

meeting WIST user needs. The National Weather Service (NWS) within the National Oceanic

and Atmospheric Administration (NOAA) is the main federal provider of weather information.

The recently completed NWS modernization of observing and information systems has already

greatly improved high-resolution weather information through more and better weather

observations, improved weather analysis and forecast models, a wider range of forecast

information, and broader dissemination of products and services. In addition to providing

weather data and services to the nation around the clock, every day of the year, the NWS also

partners with other federal programs, academia, and the private sector in research and

operational areas.

A recent initiative growing out of the NWS modernization is the National Digital Forecast

Database (NDFD). The mission of NDFD is to increase the benefits of government weather

forecasts, primarily through providing digital weather information to “drive” custom applications

developed by partners in the weather information provider community. The database is intended

to be a “seamless mosaic of NWS digital forecasts” including weather, water, and climate

forecasts from Weather Forecast Offices, River Forecast Centers, and the National Centers for

Environmental Prediction. It will begin with 5-km spatial grids prior to 2003, with the aim of

improving resolution to 2.5 km nationally after that. Temporal resolution will be 6 hours for days

1 to 3 prior to 2003, migrating to 3 hours for days 1 to 3. Temporal resolution for days 4 through

The suite of observing systems used by the

modernized NWS includes weather satellites

in geostationary orbit (GOES), Doppler

weather radars (NEXRAD), automated

surface observing systems (ASOS), and

automated rain gauge and stream gauge

networks (HYDRO). Courtesy NWS.
1-13

7 will be 12 hours. NDFD will be available to all users and partners in the public and private

sectors (Ruth 2002).

Supplementing the suite of NWS data and services, the private sector provides specialized or

value-added weather information to a wide range of WIST users. Commercial providers already

provide specialized processing of observational data from the NWS systems, mesonets, and

specialized observing systems, as well as preparing

special-purpose analyses and forecasts (many of which

are developed for surface transportation or aviation

users). A key role for the private sector in the WIST

delivery systems of the future will be information

technology applications for specialized weather services,

including value-added graphics and data dissemination

formats suitable as input for specific users’ display or

decision support systems (Smith 2001).

Intelligent Transportation Systems (ITS) and WIST

The ITS concept has been defined as “the application of computers, communications, and sensor

technology to surface transportation.” An intelligent transportation system can be viewed as a

physical transportation infrastructure supported by a communication and information network.

An objective of ITS is to provide highway and transit systems with communication capabilities

that are already part of air and maritime transportation. These capabilities include controlling

elements of the physical infrastructure, dispatching resources, and informing users (ITSA 2002).

ITS as a guiding concept for surface transportation traces back to research authorized under the

1991 Intermodal Surface Transportation and Efficiency Act (ISTEA). The Department of

Transportation administers the resulting research and subsequent deployment programs through

the ITS Joint Program Office, but ITS programs are overseen by various agencies with

responsibilities for surface transportation. Academic and private-sector organizations are

involved in much of the work. In practice, ITS programs have to date primarily covered the

highway and transit transportation sectors, with little application yet to other sectors of surface

transportation.

The connection between ITS and WIST, in essence, is that ITS provides a means to

communicate WIST to anyone connected to an intelligent transportation system’s

communications network. The National ITS Program has established a functional standard for

ITS communication networks called the national ITS architecture.2

 This architecture, based on

the concept of open systems, currently defines 32 user services and the interfaces between them.

WIST information would be one of the information types flowing into some of these user

services, for example the Maintenance and Construction Operations service. User-oriented

information tools—such as graphical display systems or decision support systems—that are

connected to an ITS-compliant system can be designed to make use of WIST data available on

 

2

 The national ITS architecture can be accessed in full at <http://itsarch.iteris.com/itsarch/>.

“The provision of weather information in

the United States is essentially a

partnership between the public sector and

the private sector.”

Jimmie Smith

Chair, AMS Board of

Private Sector Meteorology

Source: Smith 2001, p. 76.
1-14

that system. Thus, the ITS architecture provides a technical foundation for delivering WIST in a

form relevant to the diverse needs of users.

An ITS communications architecture can also aid in gathering WIST observation data. For

instance, the Environmental Sensor Station interface standard in the national ITS architecture can

be used to pick up observations from environmental sensor stations along roadsides or railbeds.

WIST and Surface Transportation Decision Support Systems

A decision support system, as this term is typically used, means a computer-based information

processing and display system (hardware and software) that incorporates a variety of data inputs

and processes them into an information product (e.g., a graphical display, an audio message, or a

printed report) useful to a subsequent decision process. This decision process may occur in the

thinking of a system manager or operator, or it could be automated as another computer-based

application. Typically, though, current decision support systems are designed to aid human

decision makers by giving them highly pertinent information in a form the user can understand

quickly.

Decision support systems that incorporate WIST input data can be as simple as roadside traffic

advisory signs or a 511 telephone number service for recorded traffic advisory information.

Advanced traveler information systems (ATISs) have proven successful in giving travelers

alternative routes to avoid congestion and incidents. Studies of recent ATIS deployments have

found that they: (1) help drivers make better-informed choices; (2) assist drivers in avoiding

congestion and unexpected delays; and (3) reduce the time spent driving (Lappin 2000). These

systems show that reliable and timely information about current and future weather conditions

enables people to make better decisions about their particular activities and contributes to their

safety, as well as increasing the efficiency of those activities. Three examples of current decision

support systems that incorporate WIST are described below.

ATWIS. One example of current technology for providing in-vehicle information on road

conditions and weather forecasts is the Advanced Transportation Weather Information System

(ATWIS). ATWIS began as a means of providing route-specific road condition reports and

nowcasts (forecasts from the current time through the next six hours) by cellular telephone to

rural travelers in the northern Great Plains. The weather forecasts, which are updated hourly,

Courtesy Intelligent

Transportation Society of

America.
1-15

provide information from a traveler’s present location (specified by saying the interstate highway

mile marker and direction of travel) to approximately 60 miles down the traveler’s route. Road

weather observations, including road surface conditions, are acquired through coordination with

the state departments of transportation (Owens 2000).

By 2000, ATWIS had expanded to three states (North and South Dakota and Minnesota),

covering 96,000 miles of highway. Surveys conducted by an independent evaluator found that

94.3 percent of travelers who knew of the service believed it would benefit their safety in the

future. The system also provides departments of transportation in the three states with a simple

text message and 48-hour forecast tailored to each transportation district. The surveys found that

nearly all maintenance crew supervisors read the reports daily. Ninety-five percent said that the

daily forecasts were helpful in their planning, and 75 percent altered plans or assignments as a

result of the forecasts. A commercial partner has now joined the project (Owens 2000). During

2002, the commercial deployment of this system was enhanced and expanded to include 511

service available to both land lines and cellular telephones in South Dakota and Montana.

Extension of the 511 service is planned for additional states. Additional service options are being

added on a state by state basis (Osborne 2002b).

FORETELL. FORETELL is a multi-state initiative covering the Upper Mississippi Valley

region and funded in part by the Federal Highway Administration (FHWA). The goal of the

FORETELL program is a RWIS integrated with a wider set of ITS services to enhance safety

and facilitate travel. FORETELL provides detailed weather forecasts, generated four times per

day for the next 24 hours, with hourly updates, available to users via the public Internet. Spatial

resolution is on a 10-km grid, and the forecasts are mapped to interstates and highways to predict

pavement conditions. It also collects atmospheric and road condition observations from roadside

sensors and mobile platforms, processing them into “plain English” descriptions for users. A

field operational test of the RWIS has been completed in Missouri, Iowa, and Wisconsin (FHWA

2002b). A final report is forthcoming.

FORETELL forecasts include precipitation, temperature, cloud cover, wind direction and speed,

weather radar imagery, atmospheric pressure, pavement temperatures, and 24-hour precipitation

accumulation. They also predict ice conditions and provide information on drifting snow and

roadway temperature. The FORETELL display can provide users with route-by-route

information about the specific weather parameters required to conduct their operations. For

example, it can be configured to flag sections of roads that are affected by frost, drifting snow,

ice, or snow accumulation (Sheffield 2000).

MDSS and the STWDSR Initiative. The FHWA’s Office of Transportation Operations is

sponsoring a multi-year, multiphase initiative to develop Surface Transportation Weather

Decision Support Requirements (STWDSR) as part of the Road Weather Management Program.

Early documents produced under STWDSR developed a needs analysis for decision support to

winter road maintenance managers, as a first step toward a conceptual WIST Decision Support

System (WIST-DSS). A prototype system aimed at winter road maintenance, called the

Maintenance Decision Support System (MDSS), has been developed for the FHWA by a team of

national research centers (NCAR 2002):
1-16

• Massachusetts Institute of Technology–Lincoln Laboratory and the National Center for

Atmospheric Research, representing the university research community

• The Forecast Systems Laboratory, and National Severe Storms Laboratory of NOAA

(Department of Commerce)

• The Cold Regions Research and Engineering Laboratory of the U.S. Army Corps of

Engineers

The MDSS work is guided by an Operational Concept Description, which is the high-level

specification for the WIST-DSS (Nelson 2001, p. 7). The MDSS project goal is to develop a

prototype capability that:

1. Capitalizes on existing road and weather data sources,

2. Augments data sources where they are weak or where improved accuracy could

significantly improve the decision-making task,

3. Fuses data to make an open, integrated and understandable presentation of current

environmental and road conditions,

4. Processes data to generate diagnostic and prognostic maps of road conditions along road

corridors, with emphasis on the 1- to 48-hour horizon,

5. Provides a display capability on the state of the roadway,

6. Provides a decision support tool, which provides recommendations on road maintenance

courses of action, and

7. Provides all of the above on a single platform, and does so in a readily comprehensible

display of results and recommended courses of action, together with anticipated

consequences of action or inaction.

(Mahoney 2001).

The priorities of the MDSS include developing capabilities for improving diagnostic and

prognostic weather information, supporting operational-scale road treatment decisions, and

tailoring the interface for use by winter road maintenance managers (NCAR 2002). Release 1 of

an MDSS functional prototype was made available to the public in September 2002. This

functional prototype is designed to be a template for future operational capabilities in winter road

maintenance decision support. The design is modular, so that components can be modified and

improved by organizations responsible for winter maintenance operations. The developers

In the future, snow removal operations will be

guided by road weather data from

maintenance decision support systems. Photo

courtesy Ohio Department of Transportation.
1-17

anticipate that the private sector and transportation departments at the state and local level will

jointly develop operational versions of the system (Mahoney 2002).

1.3.2 Expanding the Fundamental Knowledge Base for New Capabilities

As the preceding section illustrates, a great deal is being done with the current state of

knowledge in atmospheric and environmental sciences, as well as the state of the art in

technologies for observing systems, information analysis, modeling and forecasting, and

information visualization and communication. However, there are areas in which our

fundamental knowledge of weather phenomena is too limited to provide all the information

WIST users need, when they need it. If these needs are to be met, fundamental research must be

done to fill the gaps in what we know. The goal of such research should be to expand the

understanding of the causal factors responsible for weather elements that affect surface

transportation systems.

Weather and related information of interest to surface transportation includes conditions

throughout the boundary layer (to about 1 km altitude, higher for some weather radar

applications). But the consequences that affect the first 2 meters vertically are particularly

relevant to surface transportation. These effects include the interaction of weather with structures

above ground level and ground-surface-subsurface geophysical conditions related to weather. In

each of these domains, there are issues of the temporal and spatial resolution required to reflect

climatic and physiographic variations at the scales relevant to different transportation activities.

To provide this information, atmospheric science must be extended through better physiographic

characterization, more complete observation of the weather and weather-related elements of

interest at relevant spatial and temporal scales, and improved modeling to predict future states of

these elements. Appendix E contains a detailed list of the needed research, gathered during the

WIST needs identification process described in Chapter 2.

The observational issue is partly a matter of integrating diffuse capabilities (e.g., the variety of

nontraditional surface/subsurface observing systems) and extending other environmental

observing capabilities (e.g., higher resolution remote sensing at ground level) and new spacebased remote sensing techniques. Heat balance modeling for road temperature is a good example

of how weather modeling concepts can be applied, but further extension of current geophysical

modeling capabilities is needed before the potential benefits of this and other modeling concepts

can be reaped through technological applications.

Many environmental prediction techniques are related in their common use of observations, the

sequential processing of environmental information, or the fusion of parallel kinds of

information. Integrating these techniques to meet WIST user needs will require an open system

of environmental information (incorporating observational data and short-term extrapolations

from observations, as well as forecasts based on model outputs) that can also disseminate

information products to end users in user-friendly formats.

WIST-related research must include more than environmental sensing stations and

meteorological modeling. There must also be investigations into new remote-sensing
1-18

technologies, such as using differential Global Positioning System data to provide water vapor

information. Also needed is work in cognitive structures and knowledge representation, to guide

development of information structures that communicate useful information more effectively and

quickly to transportation system managers and crews, vehicle/vessel operators, and other

transportation decision makers. Finally, research is needed on what motivates users to pay

attention to weather information and incorporate it in the decisions that guide their daily actions.

1.3.3 Aviation Weather and Surface Transportation Weather

The situation for WIST now is reminiscent of the situation for aviation weather a decade ago. A

1994 report from a National Research Council study committee, Weather For Those Who Fly,

described the significant impacts that weather has on safety and efficiency in different aviation

sectors (air carriers, commuters and air taxis, general aviation). It presented a vision of how

technology could marry recent advances in weather observation and prediction with information

communication and visualization to provide diverse communities of aviation weather users with

information that would be far more useful and relevant to their operational decisions (NRC

1994).

A year later, a second study committee of the National Research Council shook up the status

quo. It called on the Federal Aviation Administration (FAA) to “provide leadership, establish

priorities, and ensure the funding needed to improve weather services for aviation weather users

and to strengthen related research” (NRC 1995, pg. 1). This report, Aviation Weather Services: A

Call For Federal Leadership and Action, decried the fragmentation of federal R&D programs for

aviation weather and recommended a coordinated federal effort to seize the opportunities that

science and technology were offering.

In the years after these reports were published, the FAA, NOAA/NWS, the aviation weather

services in the Department of Defense, and other agencies did embark on a much more vigorous

initiative to improve aviation weather. They clarified roles and responsibilities of key players,

including the private sector, in providing aviation weather services. The information providers

worked with the academic research community and user communities in the aviation sectors to

find a pragmatic balance between technology push and (user) requirements pull. User needs were

National Aviation

Weather Program

National Aviation

National Research Council Report, 1995 National Research Council Report, 1995

National Aviation Weather

Strategic Plan, 1997

National Aviation Weather

Strategic Plan, 1997

National Aviation

Weather

Initiatives, 1999

National Aviation

Weather

Initiatives, 1999

Reports from the National Research Council

spurred a federal interagency strategic plan for

aviation weather, leading to initiatives that are

now producing operational results.
1-19

validated, and the federal partners defined and adopted a coordinated set of requirements, to be

addressed by programs within and among the partners. These efforts not only coordinated R&D

programs but also implemented projects to transfer research results and innovative technology

into aviation operations. The fruits of this initiative are now improving the safety and costeffectiveness of day-to-day operations. Thus, the series of steps taken to improve aviation

weather provides a useful case study for the effort required to address WIST needs.

In some respects, however, the situation for WIST is even more challenging than it was for

aviation weather a decade ago. By 1994, the importance of aviation weather to the aviation

industry and the nation had already been recognized for fifty years, dating back to the importance

of weather services during World War II and every military action since. The vulnerability of the

first commercial services to adverse weather made aviation weather a priority for both the air

carriers (cargo and passenger) and the National Weather Service. Many Weather Service

Forecast Offices were co-located with an airport. By contrast, at a June 2001 meeting on the

future of intelligent transportation systems, surface transportation weather was described as “a

niche industry for the past thirty years that has received little attention from the meteorological

community” (Osborne 2001).

Compared with the more mature status of aviation weather, WIST-related R&D is still in its

early, tentative phase, as is federal agency support for implementing WIST in operational

systems. This difference is reflected in federal budget outlays (Table 1-3). Within the

Department of Transportation, weather-related operations in fiscal year 2003 totals $456 million

and is supported by $30.8 million in R&D programs. However, nearly all (97 percent) of the

operations are in aviation weather, as is 94 percent of the supporting research. The $2 million

R&D budget in the FHWA represents just 6.5 percent of the total DOT budget for weather

research.

Table 1-3 Federal Budget for Meteorology, Fiscal Year 2003

Annual Budget

Weather

Operations

Supporting

Research

Total DOT: $59.3 billion $456 million $30.8 million

 Aviation $443 million $28.8 million

 FHWA $0 $2 million

All Federal Entities:

$2.84 billion for meteorology $2.46 billion $384 million

Source: OFCM 2003

Of course, much of the federal presence in weather-related operations and in R&D for

atmospheric sciences is in other departments and agencies, particularly in NOAA/NWS, as

indicated by the bottom line in Table 1-3. A coordinated effort to develop WIST-related

applications of existing and emerging science and technology can be leveraged from this large

investment in general meteorological services and the R&D to support it. Given the significant

role that surface transportation plays in the nation’s economy and public safety, a similar table

for the federal budget in 2012 could show significant growth not just in WIST-related R&D but

also in WIST operations—but only if a coordinated WIST effort can follow the trail blazed by

aviation weather.
1-20

1.4 Roles and Responsibilities of Information Users and Providers

The primary roles in providing weather information for surface transportation are shared among

a diverse array of partners in the public and private sectors. In the public sector are federal

entities and a large number of state and local government activities. In the private sector,

commercial entities sell value-added meteorological services and products (often referred to as

VAMS). There is an even larger (in numbers and in market presence) set of commercial entities

that provide general information and communication products or services, in which WIST is now

or could be incorporated. (Broadcast and cable television news, commercial radio, newspapers,

and Internet service providers are just a few examples in this second category.) Participating in

both the public and private sector provider activities are the academic research community and a

growing number of “public-private” entities, often established with public support at the state

level.

Federal entities generate most of the general weather information and services for public use, as

well as providing regulatory guidance for both providers and users of WIST. Federal entities are

also major WIST users in their roles as regulators of, or service providers to, the surface

transportation communities. State and local entities augment federal WIST services with local or

specific types of observations and transportation-oriented weather decision aids. These entities

also constitute major WIST user communities, particularly those with direct responsibility for

maintaining infrastructure or operating transportation systems (state departments of

transportation, city and county street/highway departments, regional transit and airport

authorities, school districts, and more). The private sector includes substantial WIST user

communities, including any commercial entity involved with transporting goods or people in any

of the surface transportation sectors, as well as the VAMS and general information disseminators

on the provider side.

Partnerships and alliances are critical in this environment where thousands of entities have roles

in developing, maintaining, and operating the nation’s transportation system. The framework for

successful partnering, particularly where the federal agencies are involved, is shifting toward

more inclusive participation. There is greater consideration of multiple goals, as well as

recognition of the diverse priorities present in local, regional, national and international

activities, plans, and markets. Leadership will be essential to facilitate the changes required, but

the leaders must be willing and able to listen to and work with their partners. Building

constructive relationships will go a long way toward overcoming the obstacles to introducing

innovative ideas and technologies and proliferating their beneficial use throughout the nation.

1.5 The Path Forward

The Office of the Federal Coordinator for Meteorological Services and Supporting Research

(OFCM) has collaborated with representatives of its 15 federal partners (Figure 1-4) to sponsor

meetings and symposia to identify the weather support needs of national transportation systems.

These gatherings highlighted the need for, and merits of, coordinating the federal R&D effort to

provide a programmatic focus dedicated to weather information for surface transportation. This

effort would address the needs of users in all surface transportation sectors. An initial task
1-21

defined in the meetings was to identify, compile, and validate existing and potential needs for

WIST of the transportation communities among the constituencies of the OFCM federal partners.

Figure 1-4 OFCM federal partners in defining weather information needs.

1.5.1 Initial Endorsement for a Coordinated WIST Effort

Federal programs that include assessment of WIST user needs trace back at least as far as the

formation of a Weather Team by the FHWA, under the Intelligent Transportation System

program within the DOT (DOT 1998, p. 1). The effort to coordinate the federal effort on WIST

began the following year. On September 22, 1998, the Federal Coordinator for Meteorology and

Supporting Research presented a “Look to the Future” to the Federal Committee for

Meteorological Services and Supporting Research (FCMSSR). The FCMSSR, which is a multiagency committee of senior-level representatives from seven cabinet-level departments, six

independent agencies, and two offices within the Executive Office of the President (Figure 1-4),

was established to provide policy guidance to OFCM (Figure 1-5).

The “Look to the Future” report identified priority areas, issues, problems, and ideas to help

improve the effectiveness of interagency coordination and cooperation. Surface transportation

needs (including ground and marine transportation modes) were highlighted for attention.

Support for WIST was described as minimal, relative to the unmet needs of travelers,

transportation maintenance and traffic management operations, and transportation industries.

Both safety and economic productivity were emphasized as benefits to be gained. Coordination

among the FHWA, other partners from the Departments of Transportation and Commerce, state

and local entities, and others in the public and private sectors would be essential for defining

requirements and developing tailored decision aids. The FCMSSR agreed on the importance of

addressing WIST user needs through a coordinated effort.

 OFCM PARTNERS

Departments of: Independent Agencies:

Agriculture Environmental Protection Agency

Commerce Federal Emergency Management Agency

Defense National Aeronautics and Space Administration

Energy National Science Foundation

Interior National Transportation Safety Board

State Nuclear Regulatory Commission

Transportation 

Executive Office of the President

Office of Management and Budget

Office of Science and Technology Policy
1-22

Federal Committee for Meteorological Services and

Supporting Research (FCMSSR)

Interdepartmental Committee for Meteorological

Services and Supporting Research (ICMSSR)

Federal Coordinator for Meteorology

Standing Committees

Program Councils

National Space

Weather

Program

National Aviation

Weather

Program

Environmental

Services, Operations,

and Research Needs

Operational

Processing Centers

Environmental

Information Systems

and Communications

Integrated Observing

Systems

Climate Monitoring and

Services

Cooperative Research

Coordinating Infrastructure Coordinating Infrastructure

Working Group

for

Environmental

Support to

Homeland

Security

Figure 1-5 OFCM infrastructure.

Subsequently, in December 1998, the director of DOT’s ITS Joint Program Office spoke before

the Interdepartmental Committee for Meteorological Services and Supporting Research

(ICMSSR) on the connection between ITS and WIST. This presentation concluded with a

recommendation that a relationship be established between the FHWA and NOAA for surface

transportation weather, similar to that between the Federal Aviation Administration and NOAA

for aviation weather. In response, the ICMSSR tasked the OFCM to establish a Joint Action

Group to address mission needs and meteorological requirements for surface transportation

weather.

In June 1999, the OFCM sponsored an interagency meeting with 35 participants representing key

federal entities. The meeting, which focused on the federal entities’ views on WIST needs and

potential requirements, featured presentations by users, providers, and research organizations.

The participants supported an effort to identify and publish WIST needs that could be identified

by the federal entities, state and local governments, trade associations, and commercial and

private enterprises. In addition, the group endorsed the ICMSSR direction to establish a Joint

Action Group.

Also in June 1999, the OFCM formed an interagency Joint Action Group for Weather

Information for Surface Transportation (JAG/WIST). The JAG/WIST consisted of

representatives from 15 federal entities whose mission areas give them regulatory or operational

responsibility in four surface transportation sectors. The JAG/WIST met in July 1999 and began
1-23

planning for a symposium on WIST (the First WIST Symposium), which was held in December

1999 under the joint sponsorship of the OFCM and the FHWA.

To cover the spectrum of current and potential WIST users, the needs identification effort

gathered perspectives from intermodal, interstate, national, and international transportation

entities; the public and private sectors; and local and regional organizations. Organizing and

validating the needs submitted from these sources required extensive coordination with federal,

state, and local transportation agencies; metropolitan planning organizations; the transportation

industry; the transportation research community; resource agencies; law enforcement and

emergency response agencies; educational institutions; public interest groups; and others

committed to quality transportation. This process is discussed in detail in Chapter 2.

A second symposium (WIST II) was held in December 2000 to report on progress in identifying

and validating WIST user needs and plan next steps. (See Chapter 2 for the role of both WIST

symposia in the needs identification and validation process.)

1.5.2 FCMSSR Endorsement for Continuing the WIST Effort

The FCMSSR met on November 14, 2000, to focus on issues relevant to the transition team for

the newly elected administration. To improve road weather information, the committee

recommended investments in expanding observing networks and developing decision support

systems. The FCMSSR thus endorsed continuation of the objectives of the WIST effort it had

initiated in September 1998.

1.5.3 Strategic Thrust Areas and Next Steps in the Coordinated WIST Effort

Because of the great diversity of roles and responsibilities in the WIST provider community, a

validated set of WIST user needs does not automatically generate a corresponding set of

requirements. Understanding the needs of users is an initial step in an ongoing process. The

analysis of WIST needs in Chapter 4 supports both cross-sector and sector-specific conclusions.

In Chapter 5, these conclusions, informed by all the information gathered during this study,

provide the basis for defining the next stage of a coordinated WIST effort. Next steps are

recommended for each of six strategic thrust areas.

The opportunities for improving safety and economic efficiency across all surface transportation

sectors are burgeoning. We also have good reason to invest resources, time, and talent to pursue

those opportunities. But we must find the will and the way—politically, fiscally, and

programmatically—to seize them.
2-1

Chapter 2

Needs Identification and Validation Process

2.0 Strategy

Early in the WIST needs assessment, a decision was made to include a broad spectrum of surface

transportation sectors. Each sector was to be treated equally with respect to its information needs.

The initial sectors selected for assessment were roadways, railways, the Marine Transportation

System (MTS), and pipeline systems. Sectors for transit (metropolitan/regional transit systems)

and airport ground operations were added as the sampling process evolved.

The process began by creating a model for identifying weather information that might be needed

or useful in operating surface transportation systems in these sectors. The model included

identification of mission statements, weather factors, time scales, weather information providers,

and information delivery methods. The Joint Action Group for Weather Information for Surface

Transportation (JAG/WIST) coordinated the federal initiative. Individual members of the

JAG/WIST coordinated their agencies’ responses and provided guidance for subsequent steps in

the needs assessment.

Identification of WIST needs began with broad characterizations of transportation sectors,

without attempting to capture the nuances and variations within these sectors. The starting

objective was to identify as many weather characteristics as possible that affect surface

transportation. Then, as the needs identification process passed through successive iterations,

subsectors were identified and refined with respect to substantive differences in their weatherrelated impacts or potential actions in response to weather information. These subsectors were

eventually termed “activities” within a sector, and the term “activity” is used in Chapter 4 and in

the WIST needs templates. The rationale for delineating an activity within a sector was either the

uniqueness of the activity’s needs and requirements or differences in institutional operations

among activities within a sector.

2.1 First WIST Symposium

The goal of the first WIST Symposium, held in December 1999, was to establish national needs

and requirements for weather information associated with decision-making actions involving

surface transportation (OFCM 2000). This goal was consistent with a major theme of the historic

Transportation Equity Act for the Twenty-First Century. Former Secretary of Transportation

Rodney E. Slater, in his summary message describing this important legislation, stated that

... transportation is about more than concrete, asphalt, and steel: it is about people, and

providing them with the opportunity to lead safer, healthier, and more fulfilling lives.

Implicit in Secretary Slater’s statement was recognition of the effects weather has on the safety,

health, and productivity of the nation’s citizens. Actions to be taken in response to this

legislation included expanding the coordinated response to identified national needs. More than

120 transportation and weather professionals attended the plenary sessions and three workshops.
2-2

They represented federal entities, state and city governments, urban and rural transportation

agencies, professional and trade organizations (with member corporations), and weather service

providers (government and commercial). The sessions focused on:

• Department of Commerce and Department of Defense services and capabilities for

surface transportation decision support

• Commercial weather information production capabilities and services

• Federal entity weather information needs

• State and local weather information needs

• Weather information needs of professional and trade organizations

• Research and technology innovation for decision support.

Not surprisingly, the symposium produced some shared themes. The participants emphasized

weather events that trigger decisions, spatial and temporal dependencies, standards and formats,

decision-making authorities, user and provider capabilities and responsibilities, new initiatives,

and implementation. They emphasized both the importance of weather observations relevant to

surface transportation and the current lack of observations suited to the needs of transportation

decision makers. The attendees also overwhelmingly supported a proposal to establish a

nationwide baseline of weather information needs for surface transportation and endorsed the

pursuit of solutions that would meet their specific mission needs.

U.S. DEPARTMENT OF COMMERCE/National Oceanic and Atmospheric Administration

OFCM OFFICE OF THE FEDERAL COORDINATOR FOR

METEOROLOGICAL SERVICES AND SUPPORTING RESEARCH

PROCEEDINGS

FOR THE

WEATHER INFORMATION FOR SURFACE TRANSPORTATION:

DELIVERING IMPROVED SAFETY AND EFFICIENCY FOR TOMORROW

November 30 - December 2, 1999

Holiday Inn

Silver Spring, Maryland

Copyright University of North Dakota, Regional Weather Information Center

SYMPOSIUM

Cover from WIST I proceedings.
2-3

2.2 Initial Information Gathering

The process of identifying and building a nationwide baseline of weather information needs

began in earnest shortly after the WIST I symposium. The first stage was to identify the agencies

and activities that had a stake in this information resource. The next stage was to implement a

process to collect and validate data on WIST user needs.

To identify existing and potential WIST users, the study staff sent a letter to request

participation, with a questionnaire, to surface transportation professionals from federal, state, and

local governments and from the commercial sector. The questionnaire solicited comments on

agency missions, identification of operations impacted by weather elements, actions and

decisions taken in response to weather elements, and general information on availability of

weather information to meet user needs. This last category included sources and communications

media such as newspaper, radio, and television. The distribution list for this initial contact letter

was compiled with the help of the JAG/WIST members and other staff from the WIST-relevant

programs of the FCMSSR federal partners.

The request letter and questionnaire were sent to more than 700 persons, of which about 500

were transit managers across the United States. The 108 responses provided the basis for

expanded sampling of weather information needs from entities of transportation modes that

represented a cross-section of geographical areas and regional concerns. In addition to the data

from the replies, the staff, with assistance from members of the JAG/WIST, conducted one-onone interviews with representatives of the FCMSSR federal partners and with operations and

management officials of metropolitan transit authorities in the local area. The responses to the

initial request for participation provided two kinds of information for continuing the WIST needs

identification process. First, interested individuals from across the target transportation sectors

were identified for participation in subsequent steps of identifying and validating WIST needs.

For sectors in which there were few responses or in which major activities within the sector had

few responses, additional names were sought for and request letters were sent out.

Second, the responses to the initial questionnaire and the staff interviews were used to refine and

expand the data gathering model. Overall, the responses confirmed that weather is indeed a

factor in many phases of transportation operations. The responses also reinforced the view that

more accurate, timely, and mission-specific information about current and forecast weather will

conserve resources and enhance operational effectiveness, efficiency, and safety. Two

shortcomings of currently available weather information also emerged from these responses:

1. A lack of definitive information at the spatial and temporal scales required for many

users’ decision processes

2. A lack of specific thresholds at which information on identified weather elements was

needed.

2.3 Follow-up Survey

To address the limitations in the first questionnaire and to build upon the information obtained

from the First WIST Symposium, the questionnaire responses, and the agency interviews, OFCM
2-4

staff, with the assistance of the JAG/WIST, prepared a follow-up survey. The survey was sent to

recipients of the original WIST questionnaire, plus others identified over the course of the first

year of information gathering. More than 750 surveys were distributed.

The extended survey sought details on the time and distance scales, thresholds, and operational

decisions and actions important for each weather element of potential interest to the respondent.

The survey form was formatted as a table shell, or template, with weather elements as the rows

of the table and columns for thresholds, lead times, impacts, and mitigating actions for each

weather element.

2.4 Data Extraction and Analysis for Summary WIST Needs Templates

Data extracted from the initial questionnaires and the follow-up survey were used to identify

transportation activities (subsectors) within the six major sectors, weather elements and

thresholds, mitigating actions and key decisions, and time and spatial scale sensitivities. These

data were incorporated into summary tables of draft WIST needs, with one table for each

transportation sector. The summary tables, called WIST Needs Templates, were used in the

validation phase. The final seven templates for the six major sectors, representing all the needs

identified and validated during the study, are reproduced in Appendix B. In addition to a general

Roadways template, a template specifically for federal highways was prepared to capture the

scope and interests of programs within the Federal Highway Administration. Tracking

information for participants’ organizations and administrative data, along with general

comments, was also collected and maintained, although these data are not included in the WIST

Needs Templates.

Weather Elements

A weather element is a particular weather condition or a consequence of weather conditions that

WIST participants identified as affecting (1) transportation system operations (e.g., road or

railway maintenance; traffic management on rail, road, or marine transportation systems) or (2)

the safety, economic value, or efficiency (time as well as cost) of transportation activities using

those systems (e.g., ship or barge movement on the MTS, truck and car movement on roadways).

The categories of weather elements that emerged from the initial data gathering and the first

WIST Symposium are precipitation elements; temperature-related elements; thunderstormrelated elements; winds; visibility; tropical cyclone, sea state, and ice (on waterways); and

miscellaneous elements. Table 2-1 lists the individual weather elements, as identified by the

respondents, in each of these categories.

This list of WIST weather elements contains many traditional meteorological parameters. But it

also contains some unique and nontraditional elements for which the weather information

provider community has not routinely provided information to their customers in the past. For

example, freezing precipitation is a standard element, but “ice accumulation on structures, in

inches” is not. Likewise, air temperature is a standard element, but air temperature change rate,

rail temperature, and subsurface temperature are not. Some of the elements desired by WIST

users are clearly not meteorological in nature and would be characterized by environmental

scientists as hydrologic, geophysical, or oceanographic data. However, the users view all these
2-5

elements as conditions about which they need information and which, to them, are intrinsically

linked to the impact of weather on their operations.

Table 2-1 Weather Elements Identified by WIST Users, Grouped by General Category

Precipitation Elements

Freezing precipitation (ice)

Structure ice accumulation (inches)

Pavement ice accumulation (inches)

Frozen precipitation (snow, inches)

Snow accumulation observation

(inches)

Roadway snow depth observation

(inches)

Roadway snow pack depth observation

(inches)

Adjacent snow depth observation

(inches)

Snow/ice bonding observation (inches)

Drifting snow (inches)

Snow drift levels observation (inches)

Blizzard

Liquid precipitation

Precipitable water vapor observation

(inches)

Soil moisture

Flooding

Water course flow volume (cubic

meters per second)

Water body depths (feet)

Thunderstorm Related

Thunderstorms with lightning

(includes microburst event;

proximity to route or operations, in

miles)

Thunderstorm with hail (proximity to

route or operations, in miles)

Thunderstorms with tornado

(proximity to route or operations, in

miles)

Severe storm cell track (location,

direction, speed, severity, proximity

to route or operation area)

Temperature Related

Air temperature (°F)

Air temperature including maximum and

minimum (°F)

Air temperature (°F) first occurrence of

season

Air temperature change rate (°F per 24

hours)

Air temperature (°F relative to freezing) to

include trend (rising or falling)

Dew point temperature (°F)

Wet bulb temperature (°F)

Relative humidity (percent)

Rail temperature (°F)

Pavement temperature

Pavement freeze point temperature with dew

point temperature

Pavement condition

Chemical concentration (in-road sensor or

mobile infrared)

Water temperature

Soil temperature

Wind chill

Heat index

Cooling or heating degree days

Air stability

Winds

Wind (speed and direction), includes

microburst event

Wind—head, tail, cross (speed)

Upper air winds

Visibility

Visibility (statute miles) to include

restriction (e.g., fog, haze, dust, smog)

Sun glare

 Tropical Cyclone, Sea State, Ice

Tropical cyclone or hurricane (winds, sea

state, storm surge, flooding)

Seas (wave height in feet)

Wind wave height (feet)

High surf

Freezing spray (seas and low

temperature)

Storm surge/abnormal high or low tides

Tsunami, tidal surge

Inland ice coverage

River ice/ice gouging

Open water sea ice

Miscellaneous

Seismic activity, earthquakes (any land

motion, land slides, avalanches, etc.)

Nuclear, biological, or chemical hazard

dispersion

Atmospheric transport and diffusion

Air quality (characterization/code)

Fire and fire weather

Total sun (insolation hours per day)

Cloud cover forecast

Fair weather

Avalanche danger

Volcanism

Volcanic ash

Space weather (e.g., solar flares)

Several respondents and symposium participants commented that meteorological information

available today is heavily biased toward (1) the protection of life and property (e.g., severe

convective, winter, and tropical storms) and (2) aviation forecasts and observations. Several

expressed the belief that surface transportation weather products and services will one day be on

a par with aviation weather products. The “nonstandard” elements in Table 2-1 provide insight

into the information content that will be needed in WIST products and services to meet these

expectations in the user communities.
2-6 

Thresholds

As noted, the responses to the initial WIST questionnaire emphasized the importance of specific

thresholds at which a weather element affects a transportation activity or (in the case of multiple

thresholds) affects it differently. In some cases, any occurrence of a weather element has impacts

and requires action. For other elements, thresholds are critical to defining the users’ information

need.

Scale Factors

The data requested on scale factors included topography, time (forecast lead time required to

affect decisions or and actions), and spatial resolution.

Topography. The questionnaire and survey allowed users to comment on an agency’s area of

responsibility and the regional topography. Responses on regional topography ranged from

coastal marine environments and waterway marshlands to deserts and mountain forests.

Forecast Lead Time Required for Action-Decision. One of the most critical factors in

supporting surface transportation with weather information is, “How much lead time does the

user need?” For the WIST needs identification, lead time was defined as the advance warning

prior to an event. This advance warning gives the decision maker the time needed to make the

necessary preparations to minimize the effects of the weather on the specified event or activity.

The survey used a decision time line to solicit users’ responses on the lead times they require.

A plume of nitric acid fumes rises from an industrial accident site. Atmospheric transport

and diffusion is among the nontraditional weather elements important to WIST users.

Copyright AP Wide World Photos.
2-7 

The query was designed to focus on three conventional support cycles for weather information:

planning (climatology, historical probabilities), preparation (forecasts in near-term), and action

(nowcasting in near real-time).

When the data for the three support cycles were consolidated, four specific time segment

maxima were evident (Figure 2-1). For the planning cycle, a major response spike occurs at 3–6

months and a smaller spike occurs at 7–10 days. For the preparation cycle, a major maximum

occurs at 1–3 days. For the action cycle, a peak occurs at 1–3 hours, but the response distribution

is fairly evenly dispersed from the 6–12 hour threshold to the actual event. The distribution of

user responses along this timeline suggests that, to provide the greatest benefits, planning

information should be available up to 6 months before the weather event is likely to occur. Nearterm forecast information is needed for preparation actions three days in advance of a weather

event. Near-real-time nowcast information is needed for final implementation decisions

throughout the 12-hour period just prior to an event.

Figure 2-1 Distribution of desired lead times, all sectors.

0

20

40

60

80

100

120

140

160

0-1 hr

1-3 hrs3-6 hrs

6-12 hrs0-12 hrs

12-24 hrs

1-3 days3-5 days5-7 days

7-10 days

1 - 2 weeks

> 2 weeks

1-3 months3-6 months

> 6 months

Number of Responses

Spatial Resolution. Spatial scale refers to the spatial distribution or density of information that

users need—or would prefer to have—to support decisions in response to weather events. The

weather forecast community typically uses three broad categories to describe spatial scale:

• Synoptic scale is the scale of a typical continent-wide weather map showing features

that cover hundreds of kilometers horizontally, such as high-pressure and lowpressure systems and their associated fronts.

• Mesoscale is the scale of meteorological phenomena that range in size from a few

kilometers (horizontal scale) to about a hundred kilometers. Typical mesoscale

phenomena include local winds, thunderstorms, and tornadoes. Meteorologists

sometimes differentiate between the meso-β-scale and meso-γ-scale, where the
2-8 

former discriminates phenomena ranging from 20 to 100 kilometers in the horizontal

and the latter discriminates phenomena ranging from 2 to 20 km. (Kluzek 1999).

• Misoscale phenomena range in size from a few meters (horizontal scale) to about 4

kilometers. Typical misoscale phenomena include whirlwinds, dust devils, small

waterspouts, and channeling or funneling of winds around buildings and overpasses

or through tunnels.

Of the 262 responses received from participants in the needs identification survey, 100 included

information on spatial scale. The extracted data on spatial scale are represented by Figure 2-2.

The pattern of responses suggests two required levels of resolution; a synoptic scale and a very

strongly supported mesoscale. Not surprisingly, users want refined levels of analyses and

predictions beyond what is now available. Of the 100 responses that included scale information,

57 desired data resolution at 5 km or less.

Administrative Information

The administrative data on survey respondents includes the following information:

• Agency name Office title, e.g., Federal Highway Administration

• Organization Type of agency, e.g., federal, state, commercial, university

• Transportation mode Mode and sector distinction, e.g., Roadway, Railway

• Agency mission Narrative description of the agency’s mission

• Action-decision Narrative of the action or decision to be made that is affected by

weather

• Address(es) Mailing, office codes, email, phone numbers, etc.

Chapter 4 discusses and analyzes the responses from the questionnaire and the survey in detail,

as the basis for drawing conclusions about WIST needs.

0

5

10

15

20

25

30

35

40

< 1 km < 5 km < 10 km 10-30 km 30-70 km > 70 km

Scale of Information

Number of Responses

Figure 2-2 Spatial grid spacing desired by weather information users. A

30–70-km grid represents the state of current global atmospheric model

technology. A grid with less than 10 km spacing represents the state of

the art for modeling mesoscale phenomena.
2-9 

2.5 Validation and Verification of Sector-Specific WIST Needs Templates

The first drafts of the summary WIST Needs

Templates were distributed to surface transportation

professionals in each sector for verification and

validation. Over 165 agencies and user groups

provided inputs to the templates, answered

supplemental questions during the study, and

coordinated on validating the templates for one or

more modes of transportation within the sectors

(Table 2-2). Appendix A lists all the participants and

the transportation sectors of interest to them. Their

responses were consolidated into the appropriate

template, and a final agency validation or concurrence

was obtained for each summary template. The final

versions from this validation process are the templates in Appendix B.

2.6 Second WIST Symposium

While the First WIST Symposium focused on identifying the wide range of weather information

needs for the nation's surface transportation activities, the goal of the second symposium (WIST

II) was to provide a framework for improving weather information for those who make

operational decisions about surface transportation systems. The symposium's theme reflected

this goal: “Preparing for the Future: Improved Weather Information for Decision-Makers”

(OFCM 2001a).

The objectives of WIST II were to:

• Summarize activities and progress over the 12 months since the first WIST

symposium

• Present and discuss the status of the needs and analysis represented by the

WIST Needs Templates

• Solicit feedback on the WIST needs identification and validation process

• Identify initiatives and programs that were relevant to identifying or meeting

WIST needs and either underway at the time of WIST II or planned

• Illuminate strategic thrust areas where additional effort was required

• Identify next actions or other steps toward improving weather information for

decision makers.

WIST II brought together key stakeholders from federal entities, private industry, and the

academic research community. Reports and briefings showed significant progress in improving

weather information for surface transportation decision makers. Nevertheless, by the conclusion

of WIST II, it was clear that certain areas still require concerted attention and action. Further

actions are needed to ensure advances in technical knowledge, implementation of new

technologies, and validation of the weather information needs of surface transportation activities

in the various transportation sectors. The participants agreed on a list of actions, to be taken by

the OFCM and other participants, which would foster further improvements. Chapter 5 uses the

Table 2-2 Participating Users and Entities

24 federal agencies

15 FCMSSR partners

 9 other federal agencies

26 state departments of transportation

40 rural/urban transit authorities

13 public school districts

20 regional airports

26 trade associations

 4 airline companies

 8 railroad companies

 7 petroleum/natural gas companies

 2 government corporations
2-10 

results of the WIST needs validation process to provide a foundation for the strategic thrust areas

and next steps that emerged from WIST II.

2.7 Special-Case Needs Validation Processes

This section describes how the WIST needs data were collected and compiled for two sectors

that differed to some extent from the general process described in Sections 2.2 and 2.3.

2.7.1 Long-Haul Railways Sector

For rail transportation, the information obtained from the questionnaire and survey showed that

there are two distinct operational entities: long-haul railways versus rail as a component of local

or regional transit operations. Transit operations include bus and van service on streets and

roadways, as well as railways, such as surface “light rail” and metropolitan subway lines, which

are principally oriented toward moving people. The long-haul railways, which operate on more

than 144,000 miles of track (see Figure 2.3), provide primarily cargo services, moving over 1.8

billion tons of freight annually.1

 These long-haul railways also provide intercity passenger

service through Amtrak. The differences in operational settings, impacts, and actions of the two

types of rail transport were distinct enough to define them as separate transportation sectors for

the purposes of WIST needs identification.

 

1

 Rail mileage and freight statistics for long-haul railways are from the “Railroads and States—1999” web page of

the Association of American Railroads, available at <http://www.aar.org/rrstates1999.nsf>.

WIST II showed that significant progress had

been made to improve weather information for

surface transportation decision makers but, also

identified strategic areas that require concerted

attention and action.
2-11 

The original questionnaire and survey included 47 responses that addressed rail operations in

both categories. However, the absence of information from long-haul carriers was a concern, so a

special effort was made to seek participation from several of the major long-haul rail companies.

After the WIST II conference in December 2000, OFCM staff set up a draft WIST Needs

Template for long-haul railways and met with the Association of American Railroads (AAR), a

railway trade association, to review the weather-related information needs of the long-haul

railway sector. The AAR reviewed the draft template with its members, and their suggestions

were incorporated in a revised version. This revised template was distributed to the AAR

members, and their comments were incorporated to complete the validation step of the process.

The final WIST Needs Template for long-haul railways is in Appendix B-2.

2.7.2 Pipeline System Sector

The design of the WIST project included pipeline systems as a surface transportation sector.

Surface transportation sectors were defined as activities supporting the safe, efficient and

economical transport of people, goods, and services, so pipelines fall under the definition.

Direct and Indirect Effects of Weather Elements on Pipeline Systems

Even though pipelines are a controlled, closed system, weather elements do affect their safe,

economical, and efficient operation. The weather elements that factor into impacts and actions

Figure 2-3 Railroad network of the United States. Source: AAR 2002.
2-12 

for this sector are rarely the primary meteorological parameters such as precipitation air

temperature. For example, in October 1994, a major flood on the San Jacinto River near Houston

undermined numerous pipelines. Consequently, eight pipelines ruptured, igniting petroleum

spills into the river. More than 500 people suffered burn injuries. (The most frequent factor in

pipeline damage or failure is third-party excavations, e.g., utility trenching and digging by

private homeowners.)

The WIST Identification and Validation Process for the Pipeline System Sector

The pipeline system sector was by far the most difficult of the surface transportation sectors

about which to acquire WIST user information. Of the questionnaires and surveys distributed,

only four responses were received for pipeline systems.2

 Only one of the responses addressed

weather issues for pipeline systems and the impacts and actions related to weather elements. The

response received from the Department of Transportation’s Office of Pipeline Safety (OPS) and

information gleaned from the Code of Federal Regulations (CFR 193–195) were used to create a

follow-on survey for this sector. Few recipients of the second survey form responded until a

baseline WIST Needs Template was drafted, which incorporated the concerns of other surface

transportation sectors and the input from OPS.

The OFCM staff identified commercial pipeline companies and contacted them individually to

foster interest in participating in the WIST needs process. In addition to pipeline companies,

several pipeline trade associations were contacted. The trade associations proved an invaluable

aid in reaching the industry. The American Petroleum Institute (API) distributed the draft WIST

Needs Template for pipeline systems to its client members. API also invited OFCM staff to the

52nd Annual API Pipeline Conference, held on April 17–18, 2001, in San Antonio, to discuss the

WIST project during ad hoc meetings. This effort allowed the data gathering phase to be

completed and initiated a successful validation phase.

After the API conference, an updated pipeline template was distributed to pipeline companies

and trade association clients. This template was overwhelmingly approved and accepted as the

benchmark for weather information needed to support pipeline operations. In particular, key

personnel in one operational control center (of the Buckeye Pipe Line Company) graciously

reviewed the template and concurred with the contents.

 

2

 The vast majority of surface transportation responders were associated with the roadway and railway sectors. Only

a small segment identified pipelines as a concern.
3-1

Chapter 3

Organizations Participating in WIST Validation

3.0 Overview

This chapter presents an overview of the agencies and organizations that participated in the study

process described in Chapter 2. The partners in the Federal Committee for Meteorological

Services and Supporting Research (FCMSSR), plus the U.S. Postal Service, are described in

Section 3.1. The programs of these agencies have been and will continue to be the focus for

federal WIST technology transfer activities, as well as supporting research and development

(R&D). Section 3.2 describes state and local agencies that participated with the FCMSSR

partners in validating the weather information for surface transportation (WIST) needs compiled

in the templates in Appendix B.

3.1 Federal Entities

The federal partners in FCMSSR have constituencies that they serve, whether through regulation,

oversight, inspection, management, operations, or assistance. For this report, these various

constituencies have been grouped according to the transportation sector of predominant interest

to them. The assessment of WIST needs for which each agency has mandated responsibility or a

mission interest was also segregated by transportation sector. Table 3-1 shows this relationship

for all the participating federal entities. As this summary table illustrates, the interests and

responsibilities of most of the federal entities cut across multiple transportation sectors.

The major surface transportation and weather-related agencies, offices, and programs of the

federal entities shown in Table 3-1 are introduced briefly below. More detailed descriptions,

provided by the federal entities for this report, are in Appendix F.

3.1.1 Department of Transportation

As the federal entity with primary responsibility for shaping and administering policies and

programs to protect and enhance the safety, adequacy, and efficiency of transportation systems

and services, the Department of Transportation (DOT) has broad and deep involvement with

WIST user communities in all six of the surface transportation sectors covered by this study. As

Table 3-1 indicates, operating administrations within DOT that have constituencies in these

sectors are the Federal Highway Administration (FHWA), National Highway Traffic Safety

Administration (NHTSA), Federal Transit Administration, Federal Railroad Administration,

Federal Aviation Administration (FAA), Maritime Administration, Saint Lawrence Seaway

Development Corporation, Research and Special Programs Administration (RSPA), the U.S.

Coast Guard, and the Transportation Security Administration (TSA).

Federal Highway Administration. The roads and highways of the United States are planned,

built, and operated through a division of responsibilities between the federal government,

represented by the FHWA, and the states. The FHWA performs its mission through two main

programs. The Federal-Aid Highway Program provides federal financial assistance to the states
3-2

to construct and improve the National Highway System, urban and rural roads, and bridges. The

Federal Lands Highway Program provides access to and within national forests, national parks,

the Tribal nations, and other public lands.

Table 3-1 Federal Agency Responsibilities and Interests by Transportation Sectora

Federal Entities Transportation Sectors

Department-Agency Road Rail MTS Pipeline Transit

Airport

Ground Ops

Department of Transportation

Center for Climate Change X X X

Federal Aviation Administration X

Federal Highway Administration X

Federal Railroad Administration X

Federal Transit Administration X X X X

Maritime Administration X

National Highway Traffic Safety Admin. X X

Research & Special Programs Administration X X X X X X

Office of Emergency Transportation X X X X X X

Office of Hazardous Materials Safety X X X X X

Office of Pipeline Safety X

St. Lawrence Seaway Corporation X

Transportation Security Administration b X X X X X X

U.S. Coast Guard b X

Department of Energy

National Transportation Program X X X X

Power Marketing Administrations X

Department of Defense

Defense Logistics Agency X

U.S. Air Force X X

U.S. Navy X X X

U.S. Transportation Command X X X X X

Military Traffic Mgmt Command X X X X X

Department of Commerce (NOAA)

National Ocean Service X

NOAA Corps X

National Weather Service X X X X X X

Department of the Interior

Bureau of Indian Affairs X X X X X X

Bureau of Land Management X X X X X X

Bureau of Reclamation X X

Fish and Wildlife Service X X X

National Park Service X X

U.S. Geological Survey X

Department of Agriculture

Agricultural Marketing Service X X X X X X

Farm Service Agency X X X X X X

Forest Service X X X X X X

Office of the Chief Economist X X X X X X

Environmental Protection Agency X

Federal Emergency Management Agency b X X X

National Aeronautics and Space Administration X X X

Nuclear Regulatory Commission X X X

U.S. Postal Service X X X a

 An“X” in the matrix indicates an agency responsibility or interest in that sector.

b Entities designated for transfer to the new Department of Homeland Security.

The FHWA develops regulations, policies, and guidelines for federal-aid funding, with the aim

of achieving FHWA goals for mobility, safety, productivity, the human and natural environment,

and national security. It also manages a national research, development, and technology program

that includes the Intelligent Transportation System (ITS), through the ITS Joint Program Office.

In 1997 the Rural ITS program began a focus on road-weather information. This effort has
3-3

evolved into the Road Weather Management Program (RWMP) within the FHWA 0ffice of

Operations. The RWMP includes work on road-weather sensing related to prediction techniques,

dissemination of road-weather information through ITS, the development of decision support

applications that use information on weather threats, and the improvement of transportation

operations to respond to threats. It has been the FHWA lead office for interagency coordination

concerning road-weather information.

Federal Transit Administration. Through its funding program, the Federal Transit

Administration assists in developing improved mass transportation systems for cities and

communities across the country. Beyond typical bus and rail systems, it supports other forms of

public transportation, including commuter ferryboat, trolleys, and people movers. Through its

technology programs, it supports research on intelligent transportation systems, alternative fuels,

and new communication technologies. Programs and technologies such as the Bus Rapid Transit

Initiative and communication-based train control help transit services meet the current and future

needs of the traveling public.

National Highway Traffic Safety Administration. NHTSA sets and enforces safety

performance standards for motor vehicles and equipment. Through grants to state and local

governments, it enables them to conduct effective local highway safety programs. The statistics

on highway accidents, including injuries and economic consequences of accidents, cited in this

and most other WIST-related reports originate from NHTSA databases.

Federal Railroad Administration. The Federal Railroad Administration promotes safe and

environmentally sound rail transportation. It employs safety inspectors to monitor railroad

compliance with federally mandated safety standards, including track maintenance, inspection

standards, and operating practices. It conducts tests to evaluate research and development

projects that support its safety mission and enhance the railroad system as a national

transportation resource.

Maritime Administration. The Maritime Administration promotes development and

maintenance of an adequate, well-balanced, U.S. merchant marine, sufficient to carry the nation's

domestic waterborne commerce and a substantial portion of its waterborne foreign commerce. It

also seeks to ensure that the United States enjoys adequate shipbuilding and repair service,

A winter storm in the nation’s capital.

Snowplows work to clear Roosevelt

Bridge while passenger cars struggle to

cross on the inbound lanes. Copyright AP

Wide World Photos.
3-4

efficient ports, effective intermodal water and land

transportation systems, and reserve shipping capacity in time

of national emergency.

Saint Lawrence Seaway Development Corporation. In

tandem with the Saint Lawrence Seaway Authority of Canada,

the Saint Lawrence Seaway Development Corporation

oversees operations safety, vessel inspections, traffic control,

and navigation aids on the Great Lakes and the Saint

Lawrence Seaway.

U.S. Coast Guard. The Coast Guard ensures safe and secure

transportation on America’s waterways and protection of the marine environment. Its mission

includes seasonal ice observation and Ice Patrol service whenever icebergs threaten primary

shipping routes between Europe, the United States, and Canada.

Research and Special Programs Administration. The RSPA oversees rules governing the safe

transportation and packaging of hazardous materials by all modes of transportation, excluding

bulk transportation by water. It also assists local and state authorities with training for hazardous

materials emergencies. It operates the Volpe National Transportation Systems Center in

Cambridge, Massachusetts, which is dedicated to enhancing the effectiveness, efficiency, and

responsiveness of other federal organizations with critical transportation-related functions.

Within the RSPA are three offices with special relevance to WIST needs and applications. The

Office of Emergency Transportation performs coordinated crisis management functions for

multimodal transportation emergencies, including natural disasters. Natural disasters include

severe weather events such as hurricanes, tornadoes, major flooding, and similar events that

cause disruptions in transportation systems. This office also works with other federal and state

agencies to ensure relationships are in place before the stress of disaster response begins. The

functions of the Office of Hazardous Materials Safety include regulatory development,

enforcement, training and information dissemination, domestic and international standards, and

interagency cooperative activities. The Office of Pipeline Safety develops regulations and other

approaches to risk management, to assure safety in design, construction, testing, operation,

maintenance, and emergency response of pipeline facilities.

Federal Aviation Administration. The FAA oversees the safety of civil aviation by certifying

airports that serve air carriers and enforcing regulations under the Hazardous Materials

Transportation Act for shipments by air. It operates a network of airport towers, air route traffic

control centers, and flight service stations; develops air traffic rules; allocates the use of airspace;

and provides security control of air traffic. At air terminals, the FAA is responsible for

Freight trains travel at reduced speed during a high-heat day, when

rail buckling is a potential threat. Copyright AP Wide World Photos.
3-5

coordinating or controlling operational movements on the ground. It supports the collection of

weather information for aviation and other uses through automated observing systems and

human weather observers at critical locations. It also supports R&D on aviation weather.

Center for Climate Change and Environmental Forecasting. This DOT-wide virtual

organization coordinates Departmental strategies and policies for mitigating transportation’s

contribution to greenhouse gas emissions and assessing the effects of climate change on the

transportation system. Projects sponsored by the Center include impacts of climate change on

transportation, fuel options, and data analysis and modeling for transportation greenhouse gases.

Transportation Security Administration. The primary objective of the TSA is to stop terrorist

incidents before they can be implemented. Although protecting the traveling public in airports

and on airplanes may be the most visible responsibility of the TSA, it also has lead responsibility

for security of the nation’s highways, waterways, seaports, railways, public transit, and pipelines

(DOT 2002b).

3.1.2 Department of Energy

The roles of the Department of Energy (DOE) in surface transportation include the transportation

of nuclear materials, through the National Transportation Program, and access by repair crews of

the Power Marketing Administrations to electric transmission lines. The National Transportation

Program supports infrastructure and coordinates transportation activities for all nonclassified

shipments of hazardous materials, including radioactive materials, mixed wastes, and

commodities such as coal, other fuels, maintenance materials, and supplies. Within the scope of

the WIST study, the information needed by the Power Marketing Administrations is mostly

limited to weather elements that affect the ability of repair crews to service power transmission

lines.

3.1.3 Department of Defense

In addition to being a consumer of transportation weather information, the Department of

Defense (DoD) is also one of the nation’s principal producers of weather information. The Air

Force and Navy have responsibilities for weather and climate observation and forecasting

support, including severe weather warnings, for military installations and military airports,

training and maneuver areas, and wherever military operations are underway worldwide.

(Civilian/military joint use airports have different arrangements for weather support.)

• The U.S. Transportation Command is designated the single manager of the Defense

Transportation System. Strategic mobility allows the United States to act upon the

world stage at whatever level is chosen by the national leadership. The Military

Traffic Management Command, which is the overland lift component and primary

traffic manager for the U.S. Transportation Command, provides global surface

transportation to meet national security objectives in peace and war.

• Within the U.S. Air Force, Air Force Weather has the mission of providing timely,

accurate, and relevant mission weather and space environmental information to meet
3-6

Air Force, Army, Joint, and other defense and intelligence community needs

worldwide.

• The U.S. Navy has the military requirement to provide meteorological products and

services to support Navy, Marine, and Joint forces. It also provides oceanographic

support to all elements of the DoD. Operational support within the Navy is provided

by elements of the Naval Meteorology and Oceanography Command.

Air Force Weather, the Naval Meteorology and Oceanography Command, and the National

Oceanic and Atmospheric Administration (NOAA) have long cooperated in providing weather

services and continue to identify new areas of cooperation.

3.1.4 Department of Commerce and the National Oceanic and Atmospheric

Administration

NOAA, the nation’s primary civilian agency for weather data, is dedicated to predicting

environmental change and protecting the environment. NOAA provides services to the nation

through five major divisions and numerous special program units. The major divisions are

NOAA’s National Ocean Service, National Marine Fisheries Service, National Weather Service,

Office of Oceanic and Atmospheric Research, and National Environmental Satellite Data and

Information Service. NOAA also includes the nation's seventh, and smallest, commissioned

service, the NOAA Corps.

As the nation's principal advocate for coastal and ocean stewardship, NOAA’s National Ocean

Service develops the national foundation for coastal and ocean science, management, response,

restoration, and navigation. It provides nautical charting products for safe navigation to the

marine community and conducts research on the health of the coastal environment. Activities

authorized by the Coast and Geodetic Survey Act of 1947 and the 1998 Hydrographic Services

Improvement Act include programs for Mapping and Charting, Hydrographic Surveys, Geodesy,

and Tide and Current Data. These programs, along with critical weather services described in the

next paragraph, are the backbone of the information infrastructure for the U.S. Marine

Transportation System (MTS).

NOAA’s National Weather Service (NWS) provides weather, hydrologic, and climate forecasts

and warnings for the United States, its territories, and adjacent waters and ocean areas, for the

protection of life and property and the enhancement of the national economy. The NWS

maintains a constant vigil to provide warnings and forecasts of hazardous weather, including

thunderstorms, floods, hurricanes, tornadoes, winter weather, tsunamis, and climate events. It is

the sole official federal voice for issuing warnings during life-threatening weather situations. The

NWS broadcasts life-saving information to the public during severe weather events and other

hazardous situations through the NOAA Weather Radio network. Section 1.3.1 opens with a

discussion of the technological advances made through the NWS Modernization and the

importance of NWS products and services as the foundation for meeting WIST user needs.
3-7

3.1.5 Department of the Interior

Within the Department of the Interior are a number of bureaus and offices with interests related

to WIST. These include the Bureau of Indian Affairs, Bureau of Land Management, Bureau of

Reclamation, Fish and Wildlife Service, U.S. Geological Survey, and the National Park Service.

• The Bureau of Indian Affairs is responsible for 50,000 miles of road on Tribal

lands. An additional 25,000 miles of Indian Reservation Roads, which are public

roads that provide access to and within Tribal reservations, trust land, restricted Tribal

land, and Alaskan native villages, are under the jurisdiction of the Bureau of Indian

Affairs and the Tribal nations.

• The Bureau of Land Management manages 266 million acres of federal land and

570 million acres of subsurface federal mineral resources. On these public lands, it

administers about 85,000 right-of-way authorizations, including a variety of

transportation-related systems for roads, railroads, and pipelines. It maintains and

manages an additional 81,000 miles of roads for public use on the public lands. and

180,000 miles of rivers and streams running through them.

• The Bureau of Reclamation has constructed more than 350 large dams and

reservoirs in the 17 western states, including Hoover Dam on the Colorado River and

Grand Coulee Dam on the Columbia River. These dams affect major inland

waterways and lakes, particularly for recreational boating.

• The Fish and Wildlife Service operates the National Wildlife Refuge System, which

comprises 10,000 miles of roadway, about half of which is open to the public. It

maintains 10,000 miles of dikes and 23,000 water control structures to maintain

habitat.

• The National Park Service is responsible for roadways and navigable waterways

within the National Park System, which comprises 384 areas covering more than 83

million acres in 49 states, the District of Columbia, American Samoa, Guam, Puerto

Rico, Saipan, and the Virgin Islands.

• The U.S. Geological Survey (USGS) serves the nation as an independent fact-finding

agency that collects, monitors, analyzes, and provides scientific understanding about

natural resource conditions, issues, and problems. The USGS collects surface-water

data, such as gauge height (stage) and streamflow (discharge), which, along with data

collected by the U.S. Army Corps of Engineers, are used by the NWS River

Forecasting Centers to make critical flood forecasts throughout the nation.

3.1.6 Department of Agriculture

The U.S. agricultural sector is the largest user of freight transportation, accounting for nearly

one-third of all freight transportation services in the Unites States. Trucks are the primary

movers of agricultural products, accounting for 45 percent of all commodity transport, mainly for

short hauls. Rail is the predominant transportation mode for long hauls in regions far from bargeloading locations. Railways transport 32 percent of agricultural products. Barges, which account

for 12 percent of agricultural transport, handle large volumes of field crops, fertilizer, and
3-8

pesticides. The remaining 11 percent of agricultural commodities are transported by pipelines, air

freight, and other modes.

• The purpose of the Agricultural Marketing Service is to ensure an efficient

transportation system for rural America, beginning at the farm gate. This system

moves agricultural and other rural products on the nation’s highways, railroads,

airports, and waterways and into the domestic and international marketplace. The

program supplies research and technical information to producers, producer groups,

shippers, exporters, rural communities, carriers, government agencies, and

universities.

• The Farm Service Agency arranges for commercial ocean, ground (motor carrier and

rail), and air transportation to deliver agricultural commodities domestically and

worldwide.

• The Forest Service manages public lands in National Forests and National

Grasslands. Forest roads and recreational boating within these public lands are under

its jurisdiction.

• The Office of the Chief Economist advises the Secretary of Agriculture on the

economic implications of policies and programs affecting the U.S. food and fiber

system and rural areas, including issues related to transport of agricultural products.

3.1.7 Other Federal Entities

Five additional federal entities have WIST-related interests and participated in the WIST needs

identification and validation process:

The U.S. Environmental Protection Agency (EPA) ensures that environmental protection is an

integral consideration in U.S. policies concerning natural resources, human health, economic

growth, energy, transportation, agriculture, industry, and international trade. The EPA also

ensures that human health and safeguarding the environment are considered in establishing

environmental policy. Because air quality and water quality are major EPA responsibilities, the

effects of surface transportation systems on air and water pollution come under the EPA’s

regulatory authority.

Two primary areas of Federal Emergency Management Agency (FEMA) responsibility with

implications for WIST are evacuation management and response to nuclear, biological or

chemical (including hazardous materials, or HAZMAT) incidents. Evacuation management

includes the movement of people and resources such as emergency equipment and relief supplies

in response to major catastrophic events such as earthquakes, flooding, fires, and hurricanes.

Response to nuclear, biological, or chemical events includes evacuation of people and care for

victims. To respond effectively to these events, FEMA incorporates atmospheric transport and

diffusion information into emergency decision-making processes.

The principal WIST-related interests of the National Aeronautics and Space Administration

(NASA) involve the ground transport of spacecraft, vehicles, and equipment from one facility to

another, particularly to launch facilities. The most prevalent mode of transportation is by truck.
3-9

In addition, NASA research and development facilities provide substantial support for remote

sensing technologies, including applications for remote observation of weather and related

conditions relevant to WIST user needs.

In addition to regulating nuclear energy facilities and radioactive materials in the United States,

the Nuclear Regulatory Commission regulates the transport, storage, and disposal of nuclear

materials and nuclear wastes. From a transportation perspective, the Commission is important in

approving the packaging designs and quality assurance programs for transport of high activity

radioactive materials and spent nuclear fuel. It coordinates and develops guidance with other

U.S. government and international agencies on storage and transportation policy and safety

issues.

Transportation responsibilities of the U.S. Postal Service range from long-haul interstate

movements to local delivery. The delivery of postal services has supported development of

national transportation and communication infrastructures. It has linked urban and rural

economies and has led to the creation of the country's physical address system.

3.2 State and Local Agencies

The next tier of organizations that validated the WIST Needs Templates, after the federal entities

described above, consists of state and local government agencies. Unlike the federal agencies,

whose roles are primarily regulation, policy making, and oversight, the state and local agencies

are largely WIST users; they make operational decisions that are affected by weather. The chief

examples are the state departments of transportation, with their road and highway operation and

maintenance responsibilities. Among the WIST transportation sectors, the one with the most

types of weather-impacted activities is the roadway sector. A large percentage of the specific

At the command center for

the U.S. Postal Service,

electronic weather displays

help to keep the mail

moving during the

December pre-holiday

surge. Copyright AP Wide

World Photos.
3-10

weather information needs in the WIST template for the roadways sector were put forward by

the state transportation departments.

The interests of state departments of transportation in WIST applications have been a major

driver for university research and private-sector application development. One WIST II

participant estimated that the total

funding support from the states

specifically for WIST R&D

probably exceeds that of all federal

programs combined (Osborne

2002).

For the validation of WIST user

needs, the continental United

States was divided into four

regions, coinciding with the four

geographic regions used by the

NWS (see Figure 3-1). This

division aligns the state and local

participants in the validation

process with the NWS organizations that provide them with

regional weather information products and services. Within each

NWS region, a geographic distribution of participants was sought to represent major climatic

variations (Figure 3-2).

In addition to the state transportation departments, this section addresses rural and urban transit

authorities, public school districts, and regional airports. Figure 3-2 includes the distribution of

NWS Administrative Organization Regions

Figure 3-1 NWS regions.

Transits

State DOTs

Schools

Airports

Figure 3-2 State and local entities participating in WIST needs validation.
3-11

these state and local entities that participated in validating the WIST templates. The distribution

was designed to include locales that experience almost every kind of weather that occurs in the

United States, as well as covering the full range of transportation environments, from the vast

open spaces of the West to the densely packed urban corridor of the East Coast. (Note that the

map is only a rough representation; icon placement is only approximate. Where there are

multiple entities of the same type within the same geographic area, a single icon for that type of

entity is shown, to reduce clutter.)

3.2.1 State Departments of Transportation

Although there are some differences among the

various states, in general the core functions of the

state departments of transportation are similar and

can be expressed as a generic mission statement.

Their mission is to provide, operate, and maintain

safe, environmentally sound, and reliable

transportation systems and public facilities costeffectively. These state agencies design, construct,

operate, and maintain state transportation systems,

buildings, and other facilities. Their

responsibilities include maintaining and operating

thousands of miles of roads and thousands of

bridges. They test and license millions of drivers

and register thousands of motor vehicles, boats,

and aircraft. They assist in developing, preserving, and improving hundreds of public airports

and thousands of miles of railroads and multi-use trails. The state departments of transportation

also promote river navigation, provide financial and management assistance to public transit

systems, support safe transport of

commodities through thousands of miles of

pipeline, maintain harbor facilities and ferry

systems, and regulate intrastate commercial

carriers.

Winter Road Maintenance

A brief look at several areas important to state departments of transportation underscores the

imperative to move forward in meeting WIST needs. The first area is winter road maintenance;

state and local agencies spend more than $2 billion on snow and ice control operations each year

(FHWA 1998, p. 16). Timely decisions on snow and ice control can prevent roads from being

closed and reduce the number of accidents. Accurate decisions prevent unnecessary deployment

of vehicles and material—a crucial advantage in areas where each deployment represents a

sizeable portion of the local road maintenance budget.

In addition to resource costs, there is also a productivity cost to bear. In any given year, half of

the U.S. population has a 5 percent or greater chance of being affected by a hurricane; 69 percent

of the of the population lives in areas that normally have more than 5 inches of snowfall each

Participating State Departments

of Transportation

Western Region

Alaska, Arizona, California, Idaho, Nevada, Utah,

Washington

Central Region

Iowa, Illinois, Kentucky, Minnesota, North

Dakota, South Dakota

Southern Region

Arkansas, Louisiana, Mississippi, Tennessee

Eastern Region

Connecticut, Maryland, Maine, New Hampshire,

New York, Pennsylvania, South Carolina,

Virginia, Vermont

The primary interest in weather information of the state

transportation departments is road and highway

maintenance to ensure safe movement of traffic and

roadway integrity.
3-12

year. Seventy-four percent of the National Highway System is in the nation’s snow belt. A oneday highway shutdown due to snow costs a metropolitan area between $15 million and $93

million in lost time wages, retail sales, and taxes (Johnson 2001).

Tropical Cyclone Evacuation

A second area of great concern to

the state departments of

transportation, as well as to FHWA

and FEMA, is hurricane evacuation

of coastal areas. In 1993, 35 million

people lived in 22 coastal counties.

By 2010, this number will increase

to 76 million, and no new roads are

planned. Nearly 60 percent of the

deaths attributed to Hurricane Floyd

were drownings involving vehicles. During this one hurricane, approximately 3 million people

were evacuated from Florida, Georgia, and North and South Carolina, resulting in record

congestion problems. Because emergency center managers with the South Carolina Department

of Transportation and the State Highway Emergency Patrol had not agreed on a lane reversal

plan prior to the hurricane, lane reversal was not employed during the evacuation. Travel times

from the coastal area to inland safe havens increased by factors of two to seven times longer than

Snow removal is a major road

maintenance cost for many

states. Better WIST implementation can help reduce these

costs, while improving service

and safety for highway users.

Copyright AP Wide World

Photos.

Hurricane evacuation proceeds

more quickly by using both sides

and all lanes of a coastal highway.

Copyright AP World Wide Photos.
3-13

normal. The average travel time of 30 minutes from Savannah to I-95 became 3 hours, and the

two-to-three hour trip from Charleston to Columbia, South Carolina, grew to between 14 and 18

hours (FHWA 2002d). These consequences, in terms of both safety and economic costs,

highlight the critical importance of accurate forecasts with lead times long enough to make

decisions to evacuate and then carry out the evacuation efficiently.

3.2.2 Rural and Urban Transit Authorities

Transit authorities, both urban and rural,

provide a basic transportation network and

commuter resource that is an alternative to

the private automobile. Transit authorities

build, operate, and maintain these transit

systems. While buses and rail vehicles are

the most common types of public

transportation, other types are commuter

ferryboats, trolleys, inclined railways,

subways, and people movers.

In many areas, rural transit operators

provide services to a diverse clientele that

often is spatially dispersed and includes the

elderly and the medically or physically

challenged. In inclement weather, safe and

reliable operation becomes even more

important to these travelers. Unfavorable

road conditions, vehicle delays, or failure

to make pick-ups as scheduled can mean

that medical appointments and other

essential routines of daily life are missed.

These consequences add complexity to

rural operations. Timely and accurate

weather data complements real-time

decision-making and allows for more

comprehensive transit planning, adding

significant value in ensuring clients are

picked-up promptly and arrive safely at

their destinations.

Forty transit authorities (see text box)

participated in WIST project and specified

weather information needs for systems

ranging from ferryboats serving

Bremerton, Washington, to traditional

buses in Omaha, Nebraska.

Participating Rural and Urban Transit Authorities

Western Region (including Alaska and Hawaii)

People Mover Anchorage Public Trans., AK

Fairbanks, AK

City of Phoenix, AZ

METROLINK South. Calif. Regional Rail Authority, Los

Angeles, CA

Bay Area Rapid Transit, Oakland, CA

Sacramento Regional Trans Authority, CA

Honolulu Transit, HI

Great Falls Transit District, MT

Cherriots Salem Area Mass Trans, OR

Salt Lake City Transit Authority, UT

Kitsap Transit, Bremerton, WA

Central Region

Denver Regional Transportation District, CO

Rockford Mass Transit District, IL

South Central Illinois Mass Transit District, Centralia, IL

Grand Rapids Area Transit Authority, MI

Metro Transit (Minneapolis/St. Paul), MN

Kansas City Area Transportation Authority, MO

Omaha, NE

Milwaukee County Transit System, WI

Cheyenne Public City Bus, WY

Southern Region

Birmingham-Jefferson County Transit Authority, AL

Palm Beach County Transit (PalmTrans), FL

Metro Atlanta Rapid Transit Authority, GA

Oklahoma City Metro Transit, OK

Memphis Area Transit Authority, TN

Corpus Christi Regional Transportation Authority, TX

Fort Worth Transportation Authority, TX

Eastern Region

Greater Hartford Transit District, CT

Massachusetts Bay Transportation Authority, Boston, MA

Montgomery County Dept. of Public Works and Transportation,

MD

City of Charlotte, Dept. of Transportation, NC

Research Triangle, NC

New Jersey Transit, Newark, NJ

New York City Dept. of Buses and Rails, Brooklyn, NY

The Greater Cleveland Rapid Transit Authority, OH

Miami Valley Regional Transportation, Dayton, OH

Southeastern Pennsylvania Transportation Authority,

Philadelphia

Charleston Area Regional Transportation Authority, SC

Hampton Roads Transit, VA

Potomac & Rappahannock Transportation Community, VA
3-14

3.2.3 Public School Districts

Whether large or small, whether rural, suburban, or urban,

the transportation interests of public school districts are

generally the same: the safe and efficient transportation of

their students to and from school. Most districts operate

fleets of buses, similar in many respects to transit authorities.

Fairfax County, Virginia, for example, currently transports

more than 104,000 students every day, covering more than

5,000 routes with 1,428 school buses.

In addition, many rural and suburban school systems have

another dimension to their transportation problem, which

they take seriously. This aspect is the large number of

inexperienced, young drivers who drive privately owned

vehicles to school. As expected, school systems place the

safety of their students first when considering inclement weather decisions. That policy often is

reflected in decisions that serve to keep students off the roads during peak traffic periods if road

conditions are unfavorable. Prime examples include

delaying the opening of schools or dismissing students

early, both of which limit students’ exposure on the

roads during the peak commuter travel times, whether

the students are in buses or private autos.

3.2.4 Regional Airports—Airport Ground Operations

Discussions with airport operations personnel for the WIST study covered a wide range of

weather support issues, driven largely by variations in climate associated with the geographic

location of the airport. However, even with the diversity in the details received, it was possible to

find ranges of values for thresholds and lead times that could be applied to the meteorological

events of concern. Further, operational users of weather information were able to concur in the

way their individual concerns were treated in the groupings presented in the WIST template for

airport ground operations.

Early in the discussions between the OFCM staff and the airport operational personnel,

agreement was reached on how to use the terms “advisory” and “warning.” An advisory is an

alert to the possibility of a particular weather event, including its expected magnitude and

duration. In general, advisories have their greatest utility when issued 12 to 24 hours before the

weather event occurs. They provide time for planning and marshaling resources to deal with an

impending weather event. A warning is issued closer to the start of an event, when the

meteorological data support a more accurate analysis and forecast with regard to start time, type

of event, magnitude, and duration. Warnings generally have their greatest utility when issued 3

Participating Public School

Districts

Western Region

Bozeman, MT

Phoenix, AZ

Salem, OR

Salt Lake City, UT

Central Region

Chicago, IL

Kansas City, MO

Minneapolis, MN

Southern Region

Atlanta, GA

Jackson, MS

New Orleans, LA

Eastern Region

Charlotte, NC

Cleveland, OH

Fairfax County, VA

The WIST interests of school districts are similar to transit

authorities, with an added concern for young, inexperienced

drivers commuting to schools as students.

“Safety is primary in all decisions.”

Greg Clemmer, Charlotte-Mecklenburg

Schools, NC
3-15

to 6 hours in advance of an event’s occurrence. Warnings typically trigger specific actions to

ensure that all the right preparations have been taken by the time the weather event is likely to

occur, so that the event is dealt with efficiently and effectively.

The FAA issues advisory circulars to provide guidance

to airport owners and operators in developing

procedures to deal effectively and efficiently with

different situations. A number of the existing advisory

circulars treat a variety of situations affected by

weather elements. The FAA office responsible for

issuing these circulars is FAA/AAS-100. Within the

framework of guidance provided by the advisory

circulars, each airport establishes policies and

procedures for dealing with weather-related events.

While a great deal of commonality exists, allowances

are made for geographic location, climate, volume of

traffic, number of runways, and other characteristics

specific to a given airport. In all cases, close

coordination must exist between airport operations and

air traffic control, as well as between airport operations

and all airport tenants.

In the area of current weather support, the WIST study

found that virtually every airport operations center

contacted derives its weather information from the

following sources: the local weather observation taken

at the airfield, a service provided by a commercial

vendor, the Weather Channel, the local TV station, and to some degree, sources on the Internet.

Some airport operations centers continue to work closely with the nearest NWS Weather

Forecast Office, even though some of these offices have recently moved away from the airport in

order to be collocated with a NEXRAD weather radar site. New technology will contribute to

improved weather data displays and to increased accuracy of forecasts, nowcasts, and

observations. These improvements are eagerly anticipated by airport operations personnel. They

recognize that they can help their situation by a more rigorous and articulate expression of their

WIST needs.

Additional opportunities to address WIST needs for airport ground operations include extending

the application of existing DOT/FAA investments in weather information technologies and

services. Examples include the Integrated Terminal Weather Systems and Weather Support to

De-icing Decision Making, both of which are operational technologies.

List of Participating

Regional Airports

Western (including Alaska and Hawaii)

Seattle-Tacoma, WA

Los Angeles, CA

Salt Lake City, UT

Phoenix, AZ

Anchorage, AK

Central

Minneapolis-St. Paul, MN

Chicago-O’Hare, IL

Denver, CO

Grand Forks, ND

Omaha, NE

Offutt AFB, NE

Southern

Dallas-Ft. Worth, TX

Atlanta, GA

Miami, FL

Eastern

John F. Kennedy, NY

Charlotte, NC

Washington-Reagan, VA

Washington-Dulles, VA

Andrews AFB, MD

Boston, MA
4-1

Chapter 4

WIST User Needs—Analysis and Conclusions

4.0 Overview

This chapter summarizes the results of, and

draws general conclusions from, the analysis

of the user-validated WIST needs compiled

in the templates in Appendix B. General

conclusions, which cut across the sectors,

are discussed first, followed by sectorspecific results. The chapter ends with four

overarching themes about the potential benefits from meeting users’ needs for improved weather

information and the utility of the WIST templates for guiding this significant national effort.

Chapter 5 uses these conclusions and themes as the basis for suggested next steps in six strategic

thrust areas for continuing a coordinated interagency initiative on WIST implementation and

supporting research.

4.1 User Needs: General Conclusions from the WIST Study

The general analysis of the WIST data across all transportation sectors supports some general

conclusions and underscores a set of basic information needs. The four conclusions, which are

discussed in the remainder of this section, can be summarized as follows:

• Users recognize the value of weather information.

• Users want weather information tailored to their activities.

• Users’ WIST needs cover a broad range of weather elements, thresholds, and lead times.

• Within transportation sectors and subsectors, users differ in their knowledge of how

improved weather information could affect their activities and their awareness of WIST

sources.

Beyond these general conclusions, the analysis found significant differences in specific user

needs among and within the transportation sectors. (As noted in Chapter 1, for this report a user

need is defined as a specific combination of weather element, user activity, threshold, and lead

time.) These differences provide the basis for the sector-specific analyses in Sections 4.3 through

4.8.

4.1.1 Users Recognize the Value of Weather Information

The value of accurate weather information is well recognized throughout the surface

transportation user community. Highway maintenance managers concerned about freezing

precipitation, pipeline operators worried about hurricane-induced tidal surge, and vessel captains

concerned about keel clearance in shallow water must take actions whose consequences depend

critically on accurate and timely knowledge of weather and related conditions. Decision makers,

regulators, and operators across the spectrum of transportation activities confirmed the value of

The conclusion that emerged most clearly and

prominently from the WIST study is that weather

information that better meets the sector and activityspecific needs of users will reap benefits in improved

safety and increased cost-effectiveness of surface

transportation activities.
4-2

appropriate weather information for improving safety and enhancing the efficiency and

effectiveness of their activities. New technologies can improve information systems,

maintenance tools, and road weather management practices. This will help transportation

officials reduce weather-related costs, provide more accurate and up-to-date information to the

public, and decrease the number of weather-related traffic injuries and fatalities.

4.1.2 Users Want Information Tailored to Their Activities

Transportation decision makers want detailed,

location-specific forecasts and situation reports. They

also need multiple ways of getting the information—

from radio and television, the Internet and other

electronic data links, and other communications

media. In every transportation sector, users stressed the importance of getting weather

information tailored for the activity or decision-making process for which they are

responsible. This manifested itself in several ways. Users said that large-scale, general-area

weather information was inadequate for their needs. Repeatedly they stated the need for

information that is much more precise, focused, and relevant to their decision thresholds. The

general analysis of user needs shows that they want higher resolutions, both spatial and temporal.

At the same time, they demand better accuracy in the forecasts, especially for the longer ranges

(from 12 hours out to many days).

An important point made by a number of users is worth emphasizing: a forecast of favorable

weather is often just as valuable as a forecast of adverse or mission-limiting weather. This

point is sometimes lost on the weather information supplier community, where the focus has

been on correctly forecasting the onset, duration, and intensity of “bad” weather. The road

maintenance community provides a salient example. In most states, road maintenance is

performed by the same crews and trucks that clear, plow, and sand roads in the winter. To

perform maintenance work, the trucks must be physically reconfigured from their wintertime

duties. Operations managers in these states must be assured of a stretch of “good” weather—at

least 5 to 7 days—before they can risk starting a maintenance project.

Another important point about user-specific needs is that observations of current weather (the

current values of certain key parameters) are as important to some users as the forecasts for those

same parameters. For example, current observations of ice and snow accumulations,

temperatures, and severe convective weather are particularly important for road maintenance,

school and commercial bus operators, and transit authorities.

These needs for current observations are relevant to two other topics. First is the broad issue of

coordinating regional weather/environmental observing networks, sometimes called mesonets,

which are proliferating around the country. Although each network may be effective and useful

for its original purposes, there is no common standard for the attributes and formats of the data

collected from them. This lack of coordination on data compatibility undermines the potential

value of “mesonet” data as a finer-scale complement to the national observing systems. For

WIST needs in particular, where finer spatial and temporal scales are often critical to meeting

users’ decision support requirements, these regional observing systems represent a potential

Repeatedly, users stated needs for information

that is much more precise, focused, and

relevant to their operations.
4-3

wealth of high-resolution weather data. The potential economic value to tailored WIST

applications (i.e., applications developed and distributed primarily through commercial

providers) could provide an incentive for agreement on voluntary standards, with appropriate

leadership on this issue. This topic will be addressed further in Chapter 5.

The second issue related to weather observations is more conceptual for the near term, but it

could have important consequences in the longer term. In many cases where users want to know

current conditions, they do not actually require observations. Rather, they only require weather

information that is accurate, valid for the current time, and at the scale and resolution that

matches their activity. At some point in the future (although not yet), high-resolution, very fine

scale forecasts and nowcasts prepared for these users will meet at least some of these needs.

For example, a state or county highway department that needs to know the current depth of snow

accumulation along rural highways could use a model-based interpolation of the snow depth

along the roadway, based on “anchoring” observations taken at key locations along the road. To

the extent that such a model also supports prediction of conditions, even for one to several hours

after the latest observations, such nowcasts provide a substitute for strictly observational data.

The Advanced Transportation Weather Information System (ATWIS) is providing short-range

nowcasting of this kind already (Owens 2000, pp. 11-13). In essence, the users’ requirement is

for weather information that accurately describes current conditions. Provided that short-range

nowcast information is reliably accurate for the time that a user’s decision must be made, it

should not matter to the user whether the information comes directly from an observation or a

forecast (based on observational inputs).

4.1.3 WIST Needs Cover a Variety of Weather Elements, User Activities,

Thresholds, and Lead Times

Taken as a whole, the WIST needs elucidated by the surface transportation community

encompassed many different weather elements, including a range of important environmental

conditions that depend on “the weather” as commonly understood but are not always viewed as a

part of the weather. Examples include ground surface and rail temperatures, wave height and

tidal predictions, and air quality. The WIST needs also cover a broad range of desired lead times

and thresholds, as defined in Chapter 1, for various user activities within each transportation

sector.

The Weather Elements

Table 2-1 groups the weather elements identified by WIST users during the identification and

validation process into seven categories. As noted in Section 2.4, this list contains many

traditional meteorological parameters, but it also contains “weather elements” that have not been

included in conventional weather reporting and forecasting. “Ice accumulation on structures, in

inches” and “rail temperature” are just two examples of these nontraditional elements. Although

environmental scientists might categorize these elements as hydrologic, geophysical, or

oceanographic data, the users view all of them as need-to-know information intrinsically linked

to the impact of “weather” on their operations.
4-4

Analysis of Activity–Element Combinations

An “activity” is a grouping of functionally similar or identical WIST users within a

transportation sector. For example, WIST user activities within the roadways sector include road

maintenance operations, bus operations, state police, and others. The long-haul railways sector

has activities for railroad stations and depot operations. Among the activities in the U.S. Marine

Transportation System (MTS) are inland waterway recreational boating and open water

cargo/freight operations.

The combination of a weather element

and a sector activity is a useful level of

aggregation for discussing WIST user

needs. For example, freezing

precipitation (ice) is a weather element

that affects 11 roadway sector activities,

including road maintenance, truck

operations, fleet utility and transport

vehicle operations, bus operations, and

private vehicles. In the remainder of the

report, these combinations of the sector

activities impacted by a weather element,

as defined in the WIST needs templates

in Appendix B, will be called “activity–

elements.” Each activity–element thus

includes all the WIST needs (i.e.,

combinations of element, sector activity,

threshold, and lead time) for one sector activity and weather element. Figure 4-1 shows the count

of activity–elements for each of the transportation sectors represented in the WIST needs study.

Figure 4-2 shows the distribution of activity–elements among the element groups defined in

Table 2-1, for each of the six transportation sectors. Although all the transportation sectors are

subject to the same weather

conditions, the sectors vary

with respect to which groups

of weather elements

comprise larger or smaller

shares of the sector’s total

weather information needs.

The distribution of activity–

elements among the weather

groups for each transportation sector will be discussed

in detail in Sections 4.3

through 4.8. A few general

observations about the

distribution, as shown in

Figure 4-2, are made here.

Figure 4-1 Activity-element combinations by sector.

256

129 141

38

128

188

0

50

100

150

200

250

300

Roadway

LongHaul Rail

Transit

Airport

Gnd Ops

Pipeline

MTS

Acrtivitiy-Element Count

Figure 4-2 Distribution of activity-elements by sector.

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Roadway

LongHaul Rail

Transit

Airport

Gnd Ops

Pipeline

MTS

Percentage of Element-Activity Combinations

Precipitation

Thunderstormrelated

Wind

Visibility

Temperaturerelated

Trop Cyc & Sea

State, Ice

Miscellaneous
4-5

A surprising result is the relatively high proportion that tropical cyclone and sea state conditions

represent among the activity–elements for the pipeline systems sector. The importance of this

group reflects the crucial nature of physical components of the pipeline transportation system

that are vulnerable to tropical cyclone–induced weather, including pipeline segments that are

buried underwater or in vulnerable flood plains, pumping stations and storage facilities in coastal

areas, and similar factors. The small proportion of thunderstorm-related activity–elements for

pipelines reflects the fact that most of a pipeline system is below ground and therefore relatively

impervious to thunderstorm activity.

The high proportion of long-haul railway activity–

elements that are temperature-related illustrates the

temperature sensitivity of steel rail—a critical and

ubiquitous structural component of the rail transportation

system. Finally, conspicuously absent from airport

ground operations is the tropical cyclone category. The

explanation is that none of the airports that participated

in validating the needs templates happened to be in

coastal locations where the storm surge or flooding

associated with tropical cyclone conditions would be expected. The airports accounted for the

impacts of weather elements associated with inland tropical cyclones, such as high winds, heavy

precipitation, and low visibility, under the other weather element groups.

Lead Time Analysis

Another way to examine the similarities and differences among the WIST needs of the

transportation sectors is to look at the lead times required by the activities in each sector. The

lead time is the amount of advance notice of a weather-related event or condition that a user

needs to plan or respond effectively. For

this analysis, the lead times specified by

each sector activity for each weather

element were grouped into the six

categories shown in Table 4-1. Note that

the first category includes data or

information required from “now” up to

three hours in advance, which means this

category includes current weather

observations, as well as forecasts with lead

times up to three hours. The last category

includes all WIST needs for which the

requested lead time was 48 hours or more.

Figure 4-3 shows the distribution of lead

times among the six categories, by

transportation sector. Each bar is

normalized to 100 percent of the element–

activity–lead-time combinations requested

by users within that sector. (The actual

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Roadways

Long-Haul Rail

Transit

Airport Gnd Ops

Pipeline

MTS

Figure 4-3 Distribution of lead time categories 

(Table 4-1) by transportation sector.

48

24

12

6

3

1

Table 4-1 Lead Time Categories

 1 = Current to less than 3 hours

 (includes observations)

 3 = 3 to less than 6 hours

 6 = 6 to less than 12 hours

12 = 12 to less than 24 hours

24 = 24 to less than 48 hours

48 = 48 hours or more
4-6

Figure 4-4 Bimodal Lead Time Distribution

0

20

40

60

80

100

120

140

1 3 6 12 24 48

Lead time category (Table 4-1)

Element-activity-lead time 

combinations

Roadways

Long Haul Rail

Transit

Airport Gnd Ops

Pipeline

MTS

counts of these combinations vary widely from sector to sector, ranging from 333 for roadways

to 82 for airport ground operations.) One important pattern that can be seen in the graph is the

dominance of the block with lead times of 12 to less than 24 hours. For three sectors (roadways,

transit, and MTS), the second largest lead-time category is the first, from current observations to

less than 3 hours. The lead-time requirements for these sectors have a bimodal character,

reflecting a pattern in which users need WIST data with 12 to 24 hours lead time to prepare for

an event. They can follow up with execution decisions and operations for which more immediate

information (0 to 6 hours) is useful.

Another interesting aspect of Figure 4-3 is the small proportion of WIST needs, in every sector,

for lead times of 48 hours or more. This suggests that the decision processes now prevailing in

surface transportation communities could be better served by highly accurate and timely

forecasts out to 2 days (48 hours) than by longer-term forecast services and products with lower

forecast skill.

The bimodal character of the lead time distribution becomes more apparent when the counts of

element–activity–lead-time combinations by transportation sector are plotted against the lead

time categories, as in Figure 4-4. All sectors except pipeline system operations show a bimodal

pattern, although the trough between the preparation peak at 12-24 hours and the shorter-term

operational decision peak is shifted in some sectors. For airport ground operations, the lead-time

for influencing operational decisions appears to be somewhat longer, peaking at 3 to 6 hours,

although the preparation peak at 12-24 hours still holds.

4.1.4 Users Differ in Their Knowledge of Weather Impacts and Awareness of

WIST Sources

Several significant observations on users’

knowledge about weather impacts and sources of

WIST emerged from the needs identification and

validation effort. First, even within a sector

activity, users varied in their understanding of

how weather information could affect their

Users vary in their understanding of how

weather information could affect their

operations, and thus in their ability to

articulate that understanding in specific WIST

needs.
4-7

operations and thus in their ability to articulate that understanding in specific WIST needs. With

the exception of highway maintenance operations (in which users from many states had a goodto-excellent grasp of their weather information needs), this variability occurred across all the

transportation sectors. Within any given sector, there were users with a clear understanding of

how information on weather and weather-related conditions could make a difference in the

efficiency and effectiveness of their operations, as well as users with lesser degrees of awareness.

The latter category of users knew how the weather affected their operations; they just had not

considered how better information about the weather would be useful. In many instances, once

users had an opportunity to discuss the subject, they quickly saw how timely and more accurate

weather information could be of benefit.

A second observation is that users varied widely in their knowledge of what weather information

was available and where they could get it (information sources). Many users were fully attuned

to the wealth of information sources, ranging from dedicated Internet suppliers (including

commercial providers) to National Weather Service sources, to simply watching the weather on

television. However, other users were unaware that weather information useful for their

transportation activities was available from sources other than the commercial radio and

television reports.

Closely related to this second observation is a third: There is a tremendous range in users’

sophistication in exploiting weather information and products. Examples at one end include users

(e.g., airline companies) that have meteorologists on-staff who are an integral part of the

organization’s planning and daily operations. Others purchase sophisticated decision-assistance

products from commercial weather service providers. At the other end of the spectrum are users

who rely on the information in the weather report during the evening news on television.

An important general conclusion from these observations is that understanding how weather

affects an activity does not automatically give users an understanding of how better weather

information can benefit that activity. Education of potential WIST users, including interactions

between the users and providers of weather information, must be part of the WIST service

delivery process. A second conclusion is that, the more sophisticated the decision process is for

responding to weather information, the more beneficial periodic interaction between information

provider and consumer becomes. These interactions promote understanding of both the users’

needs and the capabilities that the provider can offer, as well as increasing awareness, by both

sides, of the value of weather information that is accurate, timely, and tailored to users’ specific

needs.

Weather Information Sources and Communications—Today and Tomorrow

During the collection of WIST needs data and the subsequent template validation with various

federal, state, and local agencies, a sample of the participants were asked a series of questions

about their weather data and products. These questions requested information about their data

sources, how they received and displayed the data, what changes they envisioned for the future,

and related issues. The answers bring to light some interesting similarities, as well as differences,

between and within the transportation sectors.
4-8

Sources of Weather Information

Twenty of the state transportation departments responded to the above questions on their sources

of weather information; the results are shown in Figure 4-5. Nearly every respondent listed at

least one commercial weather service provider, and some listed multiple providers, making

commercial providers by far the most common source of their information. This category was

followed closely by the National Oceanic and Atmospheric Administration’s (NOAA’s) National

Weather Service (NWS), which

was listed by about 70 percent of

the state transportation departments. After the NWS were

Internet access to web-based

resources and The Weather

Channel, both at 35 percent.

Almost 70 percent of these

transportation departments said

they did not envision changing

their sources in the future. By

contrast, in a (much smaller)

sample of trucking companies

the primary sources of weather

information were The Weather

Channel and NWS maps

delivered as an adjunct to

another (non-weather) information management system.

Thirty-one rural and urban transit authorities responded to the questions on information sources.

Their responses highlight interesting differences between these two major user groups. In

contrast to the transportation departments, only 19 percent of the transit agencies rely on

commercial weather service providers; 80 percent listed radio and television (including The

Weather Channel) as a primary source of information. Next in frequency of response were access

to Internet-based sources at 58 percent and NWS products and services at 55 percent. These

transit agencies listed communication with drivers in the field as a primary information source 26

percent of the time, whereas only one state transportation department did so. However, as the

transportation departments install state-of-the-art air and pavement sensing systems on their

vehicles, this source will probably be used more frequently. Among the transit authorities,

NOAA Weather Radio was used as a source by 45 percent, compared with only 10 percent of the

state transportation departments.

The public school systems that were sampled gave responses similar to the pattern from the

transit authorities. The school systems rely chiefly on commercial radio and television for

weather information but also make some use of Internet-based sources. At least one school

What is the current source(s) for the weather information used in your operations (e.g., NOAA’s National

Weather Service, Weather Channel, private provider, other)? Do you envision this changing in the future?

Figure 4-5 Sources of weather information reported by respondents.

0

10

20

30

40

50

60

70

80

90

100

Commercial

Weather

Servicesl

NWS NOAA Wx

Radio

Media (TV &

Radio)

Internet

Percent

State

transp.

depts

Transit

Pipeline

Rail

Schools
4-9

system, the Charlotte–Mecklenburg schools in North Carolina, added local utility companies and

the local airport weather information to their list of sources.

The pipeline companies generally relied on television and Internet-based sources, while the

sources for long-haul railroads more closely resembled the state transportation departments in

using commercial weather service providers extensively, in addition to television and The

Weather Channel as sources. State police organizations reported using a variety of sources,

including the NWS, Internet-based sources, radio and television, and commercial providers. The

Bonneville Power Administration has a resident meteorologist, who uses a full suite of NWS

products received through a NOAAPort terminal connection.

Of the 22 percent of the state transportation departments and 56 percent of the transit authorities

who envisioned changes in their sources of weather information, the most frequent theme was

anticipation of increased use of robust Internet applications providing real-time information.

Second in frequency were changes from infusion of new technologies.

Means of Communication

The second set of questions asked about the means of communication by which respondents

receive their weather information now, and how they planned to receive it in the future. Again

there are noteworthy similarities and differences between the state transportation departments

and the transit authorities. For both groups, the most prevalent means for receiving weather

information is radio and television (including The Weather Channel), used by 75 percent of the

responding transportation departments and 84 percent of the transit authorities. Next are Internetbased applications, at 65 and 55 percent, respectively. The response patterns diverge after this

point. Transportation departments are more likely to receive information by email (40 percent

versus 6 percent) and by telephone (52 percent versus 16 percent). However, 39 percent of the

transit authorities receive data by facsimile, as opposed to only 15 percent of the state

transportation departments. While 26 percent of the transit authorities use NOAA Weather

Radio, only 5 percent of the transportation departments do. Participants in the template review

noted that some highway departments are now using custom satellite delivery of weather

information.

School-system decision makers seem to receive their weather information by much the same

means as do the transit authorities. They rely for the most part on radio and television, followed

by Internet-based sources and NOAA weather radio. Secondary means include cell phones and

pagers, as well as two-way radio networks connected to local emergency management centers.

One school system, Fairfax County Public Schools in Virginia, placed particular importance on

talking directly with the NWS meteorologists at their local Weather Forecast Office. For the

future, school-system managers envision more reliance on the Internet and regional intranets, as

well as increased contact with emergency management agencies and local transit agencies.

By what communication means is weather information received now for your operations? By what means do

you envision receiving weather information in the future (e.g., National Weather Service Family of Services,

television, radio, the Internet, facsimile, or others)?
4-10

The responses of pipeline operators to these questions again resemble those of the transit

authorities, with primary dependence on radio, television and Internet-based sources. The longhaul railroads employ a more robust suite of communication tools, including television, radio,

the Internet, facsimile machines, and dedicated direct-line communications.

Of the 40 percent of respondents who envision future changes in their means of communication,

more than half expect to rely on the Internet or Internet-based solutions as the next evolutionary

step. The remaining responses were distributed among a variety of technologies and practices,

ranging from direct satellite read-out to pagers and cell phones.

The Recipients of Weather Information Within a WIST User Entity

The third set of questions asked to whom in the organization weather information and products

are routed for display, analysis, and decision-making. The response from the transit authorities

was almost univocal; 94 percent of those that responded indicated that the weather information

was routed to an operations center or a dispatchers’ office. The state transportation departments

were almost evenly split between routing the weather information to a central location, such as

an operations center, and sending it directly to shop and garage foremen and supervisors in the

field.

Here again, the school system responses parallel those from transit authorities. Although school

systems do not customarily have operations centers, many do have transportation dispatch

offices for the school buses. The key similarity is that the decision-making occurs at a central

point and the weather information is routed to that person or activity for use in informing

decisions.

Similarly, pipeline operators route weather information to their control/operations centers. The

railroads do this as well but also provide the information directly to locomotive cabs.

4.1.5 Significant Differences Exist Between and Within Transportation

Sectors

The user groups that participated in this study come from nearly all 50 states, and they thus

represent the full geographic and climatic spectrum of the United States. Consequently, there is

significant variation in specification of WIST needs, both between the transportation sectors and

within a sector. Often these differences exist even within a specific activity for the same weather

criteria. An example is drifting snow. Some state highway maintenance agencies require

notification for drifting snow of any amount; others (primarily in the snow belt) are only

interested when it is 8 inches or deeper. Likewise, extreme high temperatures in the desert

Southwest do not create the same magnitude of difficulties that those same temperatures do in

regions with more moderate climates. Thus, the thresholds at which a weather element is seen as

having substantial impact on a transportation activity, possibly requiring response preparation

Where is weather information currently being received in your operations (e.g. dispatch/operations center or

other)? Do you envision this changing in the future?
4-11

and implementation, vary with geography, as well as varying by sector and (sometimes) activity

within a sector.

Other factors that produce differences in WIST thresholds include the scale of an agency’s

“mission,” the scale of the decisions being made at a particular time, and the uniqueness of the

mission or transportation activity. For example, movement of spacecraft and critical components

by the National Aeronautics and Space Administration (NASA) to the launch facilities occurs on

intermittent schedules, which may be greatly affected by a weather element. Differences in

regulatory or policy guidance, such as local policy that is more restrictive than federal guidance,

can also produce varying needs with respect to thresholds and lead times. Finally, related to the

observations in section 4.1.4, users with greater sophistication about the utility of weather

information, the sources of information, and the means of acquiring it often specify needs that

may be more stringent and precise, with a sequence of thresholds to trigger a sequence of actions

on their part.

4.2 Introduction to Sector-Specific Analyses of Weather Impacts,

Mitigation Actions, and Information Needs

The remainder of Chapter 4 consists of a sector-by sector analysis of the WIST needs compiled

in the templates in Appendix B. Each major section starts by listing the set of transportation

activities, defined by the users from that transportation sector, for which the survey sought WIST

needs. Next is a brief analysis of the distribution of activity–element combinations for the sector

among the major element groups defined in Table 2-1. The third subsection is a detailed

discussion, by weather element group, of the impacts of specific weather elements on the sector

and the mitigation actions that users identified as potentially useful, if they have accurate

information at the thresholds and lead times specified. These discussions highlight just some of

the key impacts and actions for important activity–element combinations. More comprehensive

details for all weather elements, sector activities, thresholds, and lead times are contained in the

templates.

Users and operators of transportation systems (everyone from individual motorists to transit

authority managers) make daily decisions that are designed to mitigate the effects of weather on

their activities. Mitigation can range from simply increasing awareness of the conditions or

forewarning operators and travelers of impending events to taking specific ameliorative actions,

up to and including curtailing or suspending normal operations. All of these mitigation actions

are intended to avoid unnecessary cost, damage to property, or health and safety risks. Some of

the effects of weather simply cannot be

overcome. In these cases, the most

appropriate action may be to avoid exposure

to the weather event or to conditions affected

by it. In other cases, specific actions can

lessen or overcome the effects of adverse

weather conditions.

A WIST need is defined by (1) the weather element involved, (2) the transportation activity

affected, (3) the threshold(s) at which information is useful, and (4) the lead time(s) needed to

The objective is to provide accurate information

about current or future weather conditions to

those making transportation system decisions, to

aid them in mitigating the adverse impacts of

weather as much as possible
4-12

take effective mitigation action. The objective in defining user needs in these terms is to give

those who must make decisions about these actions the information they need, in time to inform

and guide their decisions. Users’ decision processes include many variables other than just

weather information. Therefore, the weather may not be the sole factor in a mitigation decision.

Moreover, decisions not within the control of a transportation agency can undo what would

otherwise have been a sound transportation decision to mitigate weather impacts. For example,

the insurance and banking industries of Hartford, Connecticut are mindful of how difficult travel

becomes for their employees when it snows. In the past, once snow began to fall, regardless of

the predicted duration, coverage, or accumulation, Hartford companies in these industries would

often release their employees at 11:00 a.m., without regard to the regularly scheduled public

transportation slow-down between the morning and afternoon rush hours. The result was a

tremendous demand for transit service at the very time that capacity was at a minimum, with

consequent delays and overcrowding. The discussions of WIST user needs in the remainder of

this chapter will illustrate some of the decisions that can be made, and actions that can be taken,

to mitigate or obviate the effects of adverse weather conditions on various transportation

systems.

4.3 Roadway Sector

4.3.1 Sector Activities

The most developed transportation sector with regard to addressing WIST is certainly the

roadway sector, with FHWA as the lead federal entity. The activities that were included in the

two Roadways templates (see Appendices B-1 and B-1.1) are listed in Table 4-2.

Traffic moves slowly on

a snow and ice covered

Interstate 235 in Des

Moines, Iowa. The

amount of snow was

enough to cause school

cancellations. Copyright

AP Wide World Photos.
4-13

Table 4-2 Roadway Activity Groups

Interestingly, state police organizations indicated that knowledge of the local effects and

variability of weather conditions gives their troopers an advantage in performing their duties.

This knowledge, coupled with accurate and timely weather forecasts, improves the ability of

police agencies to refine staffing and enforce traffic control more effectively. Often, the troopers

are the first on-scene weather observers, and this information can be relayed to the command

center for redistribution. Some states (for example, the Minnesota Department of Transportation)

even have mobile observing systems (environmental sensing systems) on board their vehicles.

These systems communicate directly to the traffic control center for immediate distribution and

input to traffic control decision systems. These organizations believe that monitoring the

environment in a proactive manner increases personnel safety and mission accomplishment.

4.3.2 Analysis of Activity–Elements

The roadway sector has the greatest number of activity–element combinations among the sectors

surveyed. This reflects both the substantial number of sector activities (Table 4-2) and the large

number of relevant weather elements identified by the WIST user groups. The 52 distinct

Road maintenance. This activity is generally where the requirements of the state transportation departments are

compiled. It includes road surface treatment for snow and ice control in the winter, as well as road and

infrastructure maintenance year-round to repair damage.

Truck operations. The primary example for this activity is commercial trucking operations, both local and long

haul.

Fleet utility and transport vehicle operations. This activity includes small to medium size fleets of utility

vehicles, such as those maintained by telephone or cable television companies, as well as the large, nationwide

fleets of mail and parcel delivery vehicles.

Bus operations. This activity is intended to cover primarily long-haul bus operations, such as interstate travel,

rather than school buses or local transit system buses, both of which are covered by the Rural and Urban Transit

Operations sector.

Private vehicle operations. Private vehicle operators, daily commuters, long-distance travelers, and local drivers,

as well as rental car operators, are included in this activity.

State/local emergency managers. This activity encompasses emergency managers at state and local levels.

State police. Although state police and highway patrol entities provided the input on WIST needs for this activity,

the information is generally valid for law enforcement and public safety officials anywhere with roadway traffic

safety responsibilities.

Forest Service. The roadway operations of the U.S. Forest Service role are limited to unimproved roads under its

jurisdiction within national forests and grasslands. But the ways in which the weather affects these roads has

major impact on all the uses of these areas.

SPECIAL GROUPS

NASA spacecraft and equipment transport. NASA’s principal concern with roadways is in transporting

spacecraft and components by land routes between its various centers and the launch facilities.

Power generating operations. The WIST needs of the power marketing administration (see Section 3.1.2) are

limited to road conditions that affect the ability of repair crews in utility vehicles to reach transmission

lines and facilities.

Manufactured home transport. This specialized activity has WIST needs that represent the general class of

high-profile vehicles, which have special sensitivities to wind and other weather elements, such as those

that affect tire traction.
4-14

weather elements of interest to decision makers in this sector is as large as any of the sectors.

(Transit sector WIST users identified needs for an equal number of weather elements. Although

the transit sector had the largest representation among study participants, it was less diverse and

therefore had fewer activity–element combinations.) The other sectors range from 9 distinct

weather elements for airport ground operations to 25 for waterways.

Figure 4-6 shows the percentages of roadway activity–elements in each weather element group.

Precipitation in various forms has the most activity–elements, accounting for 28 percent of the

total for this sector. Temperature-related activity–elements are next at 23 percent, followed by

thunderstorms and related phenomena (including tornadoes, lightning, and hail) at 14 percent.

The miscellaneous category, with 19 percent of the total, includes many unrelated phenomena

such as atmospheric transport and diffusion, fire weather, total solar insolation, forecasts of fair

weather, space weather (the local and high-altitude alterations in the earth’s electromagnetic field

caused by waves of charged particles spewed from the sun during “solar storms”), and

geophysical events such as volcanism and seismic activity.

In the initial WIST survey conducted in 2000, which preceded the development of the WIST

templates, precipitation was identified by nearly 88 percent of the 157 roadways sector

participants as a weather element group that generated information needs. Precipitation was

followed by winds, flooding, visibility, temperature-related elements, and thunderstorm-related

elements; each of these weather element groups was identified by half or more of the

respondents as generating information needs.

Figure 4-6 Roadway activity-elements by weather group.

28%

14%

4%

7%

23%

5%

19%

0%

5%

10%

15%

20%

25%

30%

Precipitation

ThunderstormRelated

Wind

Visibility

TemperatureRelated

Trop. Cyclone,

Sea State, Ice

Miscellaneous

Activity-Element Count
4-15

4.3.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on roadway sector

operations. These effects vary widely by weather element and the affected transportation activity.

As discussed in Section 4.2, weather impacts can be mitigated or obviated to varying degrees by

timely action, and response decisions are affected by many factors other than weather

information.

Precipitation Elements

Precipitation, especially freezing or frozen precipitation (ice or snow), causes the greatest

impacts for the roadway sector. Most of the activities list safety and health risks to people and

property damage risks as potential consequences of any freezing precipitation. Almost all list

similar risks for frozen precipitation (snow) as well, with the risks increasing as snow depth

increases. Road maintenance

activities are most concerned

with freezing and frozen

precipitation because these

conditions typically cause the

greatest expenditure of

resources in areas where such

precipitation occurs. They

have the most impact on

public safety, other than

perhaps a major hurricane.

Ice or snow on the roadways

mean loss of traction,

stability and maneuverability;

impaired mobility; roadway

obstructions; loss of control;

and increased occurrence of

vehicle mishaps, with

attendant injuries and risks to

life and property. For almost

all users, it means probable

schedule and travel delays.

State police organizations consistently report that freezing and frozen precipitation dramatically

impacts their operation. When the driving public chooses to travel during adverse weather, rather

than stay off the roads, the increase in accident rates shifts a larger share of police resources to

vehicle accident investigation and traffic control and away from other police functions.

For road maintenance crews, accurate knowledge of the start and ending times of a winter

precipitation event is crucial because the effectiveness of road surface treatments is highly

dependent on timing. Treating the roadway too early or too late can substantially reduce the

effectiveness of the effort to reduce the threat to life and property that freezing or frozen

precipitation creates.

Precipitation increases the safety risks on crowded urban highways. Photo courtesy

Blaine K. Tsugawa, OFCM staff.
4-16

The lead times these users require for information on winter precipitation events vary by activity,

but two time frames stand out. The first is a longer range planning time frame, which varies by

activity as follows:

• About 12 hours for vehicle drivers (enough time for them to reschedule their activities,

reroute, or choose another mode of transportation)

• 12–24 hours for bus and trucking operations (allowing them to reschedule, reroute,

postpone, or find safe-haven for vehicles and cargoes)

• 24–48 hours for road maintenance operations (allowing time to begin the preparation

process, predict the threatened area, select a treatment strategy, and prepare and deploy

treatment assets) and the U.S. Forest Service (enough time to warn campers and hikers to

evacuate threatened areas, prepare to repair and reopen roads that will be made impassable,

and initiate search and rescue operations if necessary).

A front-end loader clears an avalanche

from a Washington state highway.

Copyright AP Wide World Photos.

A police officer inspects a truck

that ran off the road on an icy

road in Vermont while attempting

to let faster traffic pass. Copyright

AP Wide World Photos.
4-17

The second lead time window of major value extends roughly from 0 to 6 hours before

precipitation begins. This corresponds to the execution phase of mitigation actions planned

earlier. For road maintenance crews, this means final decisions and initial operations to treat and

clear roads of snow, ice, and debris; deployment of treatment crews and assets; and initiating

changes in traffic flow management. This phase makes use of current observations, as well as

near-term forecasts and nowcasts.

Unless liquid precipitation is heavy, it affects most roadway activities less than frozen or

freezing precipitation does. Two exceptions are road maintenance operations—which have

concerns with traction, road submersion, drainage, and reduced visibility—and the transport

(towing) of manufactured homes on the highways (many states prohibit such transport if the

roadway is wet). In both cases, the critical threshold is any liquid precipitation at all. However,

conditions that produce flooding are of concern to all roadway activities. The lead times that

activity managers prefer to have prior to a flooding event range from 6–12 hours for local

mobilization to 1–2 weeks for road maintenance preparation and detour planning activities. For

most roadway activities, the principal action in response to a near-term flood warning is to avoid

or escape from the areas of predicted flooding.

Temperature Related Elements

The second-highest number of activity–

element combinations for the roadways sector

(23 percent of the total) involve the

temperature-related weather elements. Most of

these come from the road maintenance

community. Of the 60 activity–element

combinations, 21 involve just the air

temperature (including maximum and

minimum; temperature relative to freezing,

with rising or falling trend; temperature change

rate; and heating/cooling degree days). Another

24 are related to elements combining air

temperature and humidity (heat index and wind

chill temperature, dew/frost point, wet bulb

temperature, and relative humidity). and 12 are

related to surface temperatures and moisture

conditions (pavement and subsurface

temperatures, pavement freeze point

temperature with frost point, and pavement

condition).

Crews work in the high heat produced by the weather

and the asphalt treatment being done along State Route

10 near DeSoto, Kansas. Maintenance managers want

advanced notice of high heat days for worker safety.

Copyright AP Wide World Photos.
4-18

Road maintenance operations are highly dependent upon temperature information, particularly

the combination of pavement temperature and air temperature relative to the freezing point, with

rising or falling trend. Accurate and timely temperature information, coupled with precipitation

information, allows operators to select the correct strategy and treatment material for treating

road surfaces to minimize the effects of weather on motor vehicle operations. The Forest Service

is concerned about temperatures rising above freezing during the winter months because, as

frozen, snow-packed logging roads thaw, heavy logging trucks cause structural damage to the

roads. If this condition can be predicted accurately, the roads can be closed to heavy trucks

before damage occurs.

Sufficiently high temperatures can be a concern for most roadway activities and users. Not only

do high temperatures require caution for work crews and equipment, they pose a risk to vehicles

and freight. High pavement temperatures increase the risk of tire blow-outs for heavy loads, such

as manufactured homes being towed on the highways. State police also reported that extreme

temperatures, both hot and cold, have substantial effects on their duties and workloads with

respect to vehicle incidents on the roads and traffic flow management.

Thunderstorm Related Elements

The next most prevalent group of activity–elements for roadways are the 14 percent associated

with thunderstorms and related phenomena. Although the impacts can be very severe and include

loss of life and damage to property, thunderstorm phenomena generally affect smaller areas and

for shorter durations than some of the other weather elements. When severe thunderstorms do

occur, all the roadway activities recognize the potential risks to their people, vehicles, and

cargoes. The protective actions are similar: most activities cease outdoor operations in the path

of the threatening weather and take evasive actions as necessary.

Road maintenance activities and the Forest Service also must respond to road damage or

blockage by debris. In addition to conducting search and rescue for stranded, trapped, or injured

recreationists in the wake of a severe storm, the Forest Service must determine where valuable

timber has been knocked down and must be salvaged.

Trucking operators and NASA (during the ground transport of spacecraft and equipment) will

delay, reschedule, reroute, or seek shelter, as appropriate to protect their people and equipment.

State police reported that, although lightning does not routinely affect their mission, serious

difficulties do arise when lightning occasionally damages their communications towers and

antennae.

Visibility

Activity–elements related to visibility represented 7 percent of the total combinations for

roadways. Generally, visibility does not become a factor for roadway operations until it becomes

restricted to a quarter mile or less. At that point, most activities simply slow down and exercise

more caution. Some, however, take more specific actions. Manufactured home transporters stop

travel; trucking operators, if hauling hazardous materials (HAZMAT), may seek a safe stopping

place. NASA will try to reroute, delay movement of, or transport their cargo earlier to avoid

encountering conditions of reduced visibility on the road. An element related to visibility that
4-19

affects most roadway operations is sun glare. For most activities, the principal response action is

to reduce speed. State police added that reduced visibility is one of the weather elements that

consistently affects their operations dramatically, increasing the rate of vehicle incidents and

altering traffic flow.

Winds

Although winds account for relatively few of the activity–element combinations (4 percent) for

roadways, high winds are a concern to road maintenance activities and transporters of highprofile loads, including trucks, buses, manufactured homes, recreational vehicles, and NASA’s

road transport activities. The critical threshold for most activities is winds of 50 miles per hour

and more. The exception is transporters of manufactured homes, who typically stop travel when

winds exceed 25 mph.

Miscellaneous Elements

Several of the weather elements and weather-related phenomena in the miscellaneous group are

worth noting for their impact on roadway activities. One of these is hurricane (tropical cyclone)

storm surge, which affects all road transportation activities in the area where storm surge occurs.

The response actions are to suspend travel through and vacate the affected area. Required lead

time to respond effectively is 12–24 hours. Another element of interest to important roadway

activities is fair weather, or more precisely, accurate forecasts of the duration of fair weather.

Many activities rely on “good” weather for success or efficient operations, so an accurate

forecast of good weather is just as important as an accurate forecast of adverse weather.

A third element in this category is weather information relevant to incidents of release and

atmospheric dispersion of nuclear, biological or chemical hazards. Whether accidental or

deliberate, these events are life-threatening, and the responses by roadway activities are either to

cease operations and clear the area or participate as part of a previously trained response team. A

related element, albeit less critical in potential health effects, is air quality, which typically has

the greatest impact in urban areas. Many of the meteorological conditions that influence the

movement of a plume from a hazardous-materials release are also of importance in forecasting

air quality conditions and the areas affected.

Another element of special interest in the miscellaneous group is space weather. As the nation

grows more and more dependent on electronic and wireless systems for communication,

navigation, and data transfer, the need increases to monitor and manage the system components

that can be temporarily disrupted or permanently damaged by space weather hazards.

4.4 Long-Haul Railway Sector

4.4.1 Sector Activities

Long-haul railway operations include inter-city freight transportation and a small volume of

inter-city passenger traffic. The “light rail” systems used for metropolitan-area passenger

transportation are included in the rural and urban transit sector. The long-haul railway activities
4-20

identified by survey participants from this sector as sensitive to weather or weather-related

conditions are described in Table 4-3 and appear in Appendix B-2, the WIST needs template for

this sector.

Table 4-3 Long-Haul Railway Activities

Since 1985, the railroad industry has grown and changed. Boxcars are being replaced by intermodal containers and trailers. Warehousing is considered inefficient and expensive; the modern

business operation plan calls for “on-time delivery” instead. Accounting for the effects of

weather conditions on this time-sensitive delivery system is essential for efficient and effective

operations. Decisions made with inadequate or erroneous weather information reduce

efficiencies, increase operating costs, and decrease customer satisfaction. Each of the four major

rail carriers either has its own weather forecast staff or contracts for weather support services.

4.4.2 Analysis of Activity–Elements

Because there are so few railroad companies, the railway sector is one of the smaller user

populations in the WIST study, in terms of the number of participating entities. But this industry

concentration belies the importance of the sector to the transportation industry. Responses to the

WIST needs questionnaire were received from 22 separate entities, which identified 18 distinct

weather elements that affect

them. For the seven sector

activities identified by these

users, there

are 129 activity–element

combinations in the WIST

needs template. Figure 4-7

shows the distribution of these

activity–elements among the

weather element groups defined

in Table 2-1.

The initial WIST survey, which

was conducted in 2000 prior to

developing the WIST needs

templates, showed precipitation

as the weather element which

drew the greatest amount of Figure 4-7 Railway activity-elements by weather group.

27%

11%

5% 5%

29%

5%

16%

0%

5%

10%

15%

20%

25%

30%

35%

Precipitation

Thunderstorm

Related

Wind

Visibility

Temperature

Related

Tropical

cyclone, sea

state, ice

Miscellaneous

Activity-Element Count

Railway/control center operations. The control center monitors the railroad system and advises train and

station operators and dispatchers. It controls system integrity.

Station and depot operations. Operations at and in the vicinity of stations, involving tracks, rolling stock, and

platforms.

Hump yard operations. Includes maintenance, inspections, and local operations.

Construction. Includes scheduling, maintenance, and repair activities.

Hazardous material. Includes monitoring the transport and handling of materials, as well as mitigation,

reclamation, and reporting of events or incidents.

Surveillance. Includes inspections, monitoring, and maintenance of trackage, supporting structure, and facilities.

Personnel safety. Safety of train crews, station and depot personnel, and passengers.
4-21

interest. Nearly 83 percent of the 47 respondents from this sector indicated a need for

precipitation information. The weather elements of visibility, flooding, winds, thunderstormrelated conditions, and temperature-related elements were each identified as WIST needs by half

or more of the respondents.

Among the activity–element combinations from the template, temperature-related elements

account for the highest number, with 29 percent of the activity–element combinations (Figure 4-

8). Activity–element combinations for precipitation elements were next at 27 percent, followed

by thunderstorm-related elements at 11 percent. In the miscellaneous group, the activity–

elements are split evenly between atmospheric transport and diffusion and space weather.

The emphasis on temperature-related needs reflects the larger number of temperature-related

elements identified as important by the railways sector participants. Some of the nuances among

the precipitation-related elements that are important for roadways, transit operations, or airport

ground operations are less important for long-haul railways. However, temperatures at both the

hot and cold extremes—particularly temperature changes—have substantial effects on steel rails.

4.4.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on railway operations and

the response actions that the study participants identified as potentially influenced by accurate

information on each element. Mitigation actions can range from simply increasing awareness to

taking specific corrective actions or curtailing or suspending activities. All these actions are

intended to avoid unnecessary cost, damage to property, or safety risk to people. As discussed in

Section 4.2, weather impacts can be mitigated or obviated to varying degrees by timely action,

and response decisions are affected by many factors other than weather information.

Temperature-Related Elements

Of the 38 temperature-related activity–elements identified for the long-haul railway sector, 14

are for air temperature, including daily maximum and minimum and first occurrence of a high or

Freight locomotives are trapped and

partially derailed in ice pushed up

by rising Susquehanna River waters

near Cresswell, Pennsylvania.

Copyright AP Wide World Photos.
4-22

low for the season. Another 7 are for rail temperatures, and 7 are for soil temperature (impacts on

the railbed). The remaining 10 are for wind chill temperature and heat index, which affect

exposed personnel.

Expansion and contraction of the rails caused by changes in temperature or seasonal extremes are

of great concern to this sector. The rail industry routinely inspects all 120,000 miles of track

about twice weekly. However, the first occurrence of the fall-winter season when the air

temperature drops below freezing produces rail contraction that can cause gaps and misalignment

in the track. This greatly increases the number of track warning signals and the potential for

derailment, malfunction of track sensors and signal sensors, and signal damage. Rail contraction

continues as the temperature drops further. These conditions pose a risk to personnel (crew and

passenger) safety and risks to freight and property. Mitigation actions include increased

inspections of track and sensors; repair as necessary; slowing, stopping, delaying, or rerouting

trains; and preparations for response to HAZMAT incidents. Similarly, increasing air

temperatures produce rail expansion, which can cause “kinks” in the track beyond a certain

temperature. The seasonal thresholds are the first occurrence of air temperatures in the spring at

70–75 °F, and 90 °F. When air temperatures exceed 90 °F, additional track inspections are

prescribed.

More important than any single upper or lower threshold is the diurnal temperature variation.

Temperature changes of 30–40 °F over 24 hours can cause inconsistent expansion and

contraction, leading to track misalignment and possible rail failure. The actions taken are

essentially the same as for crossing the seasonal temperature critical points. The lead time

desired by the industry is 3 days for both hot and cold temperatures, followed by another

notification 12 hours before the threshold temperature is reached.

Two elements closely related to air temperature are rail temperature and soil temperature. Rail

temperature is of interest because of the expansion and contraction issues. The critical thresholds

are the freezing point (especially if moisture is present) and 110 °F. Soil temperature is critical at

the freezing point, as freezing and thawing of the soil can produce ground heaves, which may

result in railbed movement, making track and railbed failures and train derailments possible.

Ground heave is most prevalent during the autumn freeze and the spring thaw. Mitigation actions

Hot air rising from a rail

bed near Hollywood,

Florida, gives track the

appearance of being

distorted. Rapid

temperature changes,

particularly the first of a

season, can buckle rails

and cause accidents.

Copyright AP Wide

World Photos.
4-23

are essentially the same as for rail expansion and contraction. Each of these temperature

elements affects all seven of the railway sector activities.

Precipitation Elements

The second highest count of activity–elements for the long-haul railway sector are those for

precipitation events. The sector participants identified five precipitation elements of interest

(freezing precipitation, snow, drifting snow, heavy rain, and flooding), each of which affects all

seven of the sector activities.

As freezing precipitation (ice) builds up on structures and metal rails, the potential increases for

failure of track switches and malfunctions of track sensors, signal sensors, and signals.

Monitoring and repair requires dispatching rail and signal maintenance crews. Ice can also

require reductions in train speed, causing schedule delays, even while demand for passenger

service is surging because other modes of transportation are more affected or unavailable. Ice

increases the difficulty for railroad employees in getting to work, impedes mobility of track

inspection crews, and increases risks to personnel safety, particularly on passenger platforms at

train stations. Mitigation actions include implementing traditional snow and ice control plans,

modifying train operations (which may include delaying or rerouting trains), inspecting and

repairing tracks as necessary, or recalling additional train and maintenance crews. The lead time

desired by decision makers in this sector is 24 hours, with followup notification 6 hours before

the freezing precipitation begins. These lead times are generally the same for all ice and snow

events.

Frozen precipitation (snow) of less than 6 inches generally does not pose a problem for operation

of long-haul trains. Perhaps the best mitigation action is to keep the trains running, which keeps

the rails clear and holds accumulations at a manageable level. Snow accumulation greater than 6

inches, however, brings much the same impacts as are associated with ice, with the same range

of potential mitigation responses.

Liquid precipitation (rain) is only a problem when it is intense enough to reduce visibility, which

may cause a train crew to miss a signal unless train speed is sharply reduced (creating schedule

After the storm surge and heavy

rain from a hurricane, obstacles

lie across a flooded section of

track in Alabama.
4-24

delays). However, flooding—a byproduct of rain—can have much more serious impacts. It can

wash out portions of the railbed; damage railbed support structures, switches, sensors and

signals; or cause mudslides or high water over the tracks, which pose risks to train operations.

The rail industry operates under a “fail safe” rule: if there is a reported problem with or on the

tracks, a track inspection is required prior to resuming operations. In general, the first reaction to

reports of flooding is “when” and “where.” This approach isolates the potentially affected region,

limits suspension of operations to just the affected areas, and initiates rail inspections.

Thunderstorm-Related Elements

Tornadoes are of course the most severe threat in the thunderstorm-related group, but they are

infrequent and normally confined to a relatively small area. A much more widespread and

frequent threat is lightning strikes within 5 miles, which brings many exposed or outdoor

operations, such as refueling, to a halt. Lightning can also produce track sensor and signal

malfunctions, resulting in train delays and stops. Knowing where lightning has occurred allows

the signal repair crews to isolate more quickly the locations of signal and sensor problems.

Another problem can be the high winds associated with thunderstorms, which are addressed

below in the section on winds.

Winds, Visibility, and Tropical Cyclones

Each of these weather elements or weather-related phenomena affects all of the railway

activities.

Wind speeds in excess of 50 mph, no matter what the source, are likely to blow some types of

rail cars over, which makes it prudent for those trains to be stopped or otherwise protected.

Decreased visibility makes it more difficult to see train signals and obstructions on the track,

which increases the possibility of collisions and derailments.

In 1998, heavy rains from

Hurricane Georges washed out

350 feet of track near Crestview,

Florida.
4-25

Visibility thresholds are based on the stopping distance, which is a factor of speed, topography,

and weight. For example, a 10,000-ton train moving at 60 mph on level ground requires 1.25

miles to stop. As a rule, visibility is not a significant factor until it drops below 1 mile. As the

visibility drops, the mitigation response is to reduce train speed.

Tropical cyclones combine the effects of storm-force winds, the cumulative effects of tides and

storm surge, and inland flooding. These phenomena can scour, bury, damage, or destroy the

railbed; damage rail from line stretch and debris impact; damage structures; and cause rail sensor

and signal failures. Railbed and track failures are likely, and derailments are possible. Winds,

seas, and tides may restrict or suspend coastal rail traffic. Mitigation actions include relocating

rail assets before a storm to preclude damage or stranding, suspending rail operations in the

affected area, and cleaning up and repairing as necessary afterward. Particular attention must be

focused on rail surveillance and inspections of bridges, trestles, and railbed for structural

integrity.

4.5 The U.S. Marine Transportation System

The MTS is a key component of our national transportation system. In 1998, about 2.4 billion

tons of cargo moved on U.S. waterways and through U.S. ports. By 2020, trade is conservatively

projected to double, with the largest increase expected in container shipping. The length, width,

and draft of commercial vessels have grown dramatically over the last 50 years, pushing the

limits of many ports and posing significant safety concerns (NOAA 2001). Environmental risks

have also increased with increasing vessel size because nearly half of all goods transported are

oil or other hazardous materials. Growth in ferry, cruise line, and recreational boating also

contributes to increased congestion on our waterways. Ensuring safe and efficient port operations

is vital to maintaining the competitiveness of the U.S. port industry and U.S. exports (DOT

1999). The WIST needs study identified the impacts on this system of weather and related

elements. Characteristics of information about these elements that could help in mitigating these

consequences were identified and validated by participants from the MTS user communities, as

well as the federal agencies with responsibility for the MTS.

In 1998, Congress directed these federal agencies to assess the state of the MTS and develop a

vision for modernizing the system. This was a first step toward developing a transportation

system for the twenty-first century—a system that addresses the future of marine transportation

safety, security, competitiveness, infrastructure shortages, and environmental health. Federal

entities—in particular the U.S. Coast Guard, Maritime Administration, and NOAA—and the

private sector have partnered to support the MTS initiative by raising awareness of MTS issues.

4.5.1 Sector Activities

The sector activities of the MTS include the full spectrum of waterborne transportation on

freshwater and estuarine waterways, coastal routes, and the open sea. These activities range from

recreational boating and commercial barge traffic on inland waterways to movement of large

commercial vessels in harbors and on the open ocean. The first 10 activities in Table 4-4

constitute the waterborne component of the nation’s MTS. A closely allied activity that WIST
4-26

users in this sector wished to include is marine modeling. All 11 of these activities are covered in

the WIST Needs Template in Appendix B-3.

Table 4-4 MTS Sector Activities

4.5.2 Analysis of Activity–Elements

Participants from the MTS sector constituted the third largest population in the WIST needs

study, after roadways and transit. Responses were received from 28 separate agencies or entities

(Appendix A). These participants identified 25 distinct weather elements that affect them. When

these weather elements are combined with the sector activities affected by each element, the total

count of activity–element combinations is 188, the second highest count among the six sectors

studied.

In the distribution of these activity–elements by weather element group (Figure 4-8), the

precipitation group accounts for 20 percent. Temperature-related elements account for 19

percent. Elements in the category of tropical cyclones, sea state, and ice account for another 14

percent of the total.

In the initial WIST survey conducted in 2000, prior to developing the WIST needs templates,

“precipitation elements” was the group most frequently cited by the respondents. Of the 32

Figure 4-8 MTS activity-elements by weather group.

20%

9%

6%

11%

19%

14%

21%

0%

5%

10%

15%

20%

25%

Precipitation

Thunderstorm

Related

Winds

Visibility

Temperature

Related

Tropcial

Cyclone, Sea

State, Ice

Miscellaneous

Activity-Element Count

Inland water activities

Ferries.

Commerce; includes barge traffic on major rivers.

Recreational boating; includes fresh water lakes, rivers and streams.

Open water activities

Cargo/freight; includes large ocean-going vessels, including U.S. Navy ships.

Cruise lines.

Commercial fishing; primarily includes near-shore and off-shore salt water operations.

Recreational boating and salt-water operations.

Port operations. Operations include keeping port facilities open and safe movement of vessels in and out.

St. Lawrence Seaway operation. Operation of locks and canals, control of navigation and movement of

vessels.

NASA movement of launch vehicle/payload elements via barge. Primarily external fuel tank and solid

rocket boosters moving to and from the launch facility.
4-27

respondents for this sector, 75 percent indicated a need for precipitation information. Visibility,

winds, and flooding were identified by half or more of the respondents. The groups for

thunderstorm-related elements and tropical cyclones were cited by between 30 and 50 percent of

this initial set of WIST respondents.

4.5.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on MTS operations and the

response actions that the WIST study participants identified as potentially influenced by accurate

information on each element. Mitigation actions can range from simply increasing awareness to

taking specific corrective actions or curtailing or suspending activities. All these actions are

intended to avoid unnecessary cost, damage to property, or safety risk to people. As discussed in

Section 4.2, weather impacts can be mitigated or obviated to varying degrees by timely action,

and response decisions are affected by many factors other than weather information.

Precipitation Elements

Precipitation, especially freezing and frozen (ice and snow) precipitation, causes the greatest

impact for this transportation sector. With any amount of freezing precipitation, all the activities

show impacts to safety of personnel, impaired operations, and risk to cargo and equipment.

Almost all of the sector activities show corresponding risks and impacts with frozen precipitation

(snow) as well. Intense rain impairs operations, primarily because it reduces visibility and creates

a danger to personnel and equipment due to flooding.

Vessel operators, whether on large commercial or small recreational vessels, mitigate the risk

posed by freezing precipitation and the buildup of ice on decks and structures by limiting or

terminating on-deck activities, covering equipment, or avoiding operating in areas of, or during

periods of, freezing precipitation. When NASA moves spacecraft components by barge, all

equipment and cargo are covered, and the operator considers delaying barge movement until the

weather event has passed. Snow does not necessarily terminate operations, but it requires

operators to clear the snow from decks and consider curtailing on-deck activities. The reduced

visibility brought on by heavy rain requires extra vigilance and reduced speeds for vessels.

Representatives from the U.S. Coast Guard, in discussing operation of small and medium size

cutters on the Great Lakes, reported that no matter what the form, precipitation reduces visibility

and clutters the radar of cutters that are underway. Snowfall accumulating on a cutter affects the

cutter’s stability and the crew’s movement onboard. Snowfall on top of ice-covered waters slows

a cutter’s movements through the ice. Flooding caused by ice jams may require icebreaking

operations to alleviate the flooding.

Port operations are affected somewhat differently than are vessels underway. This sector activity

involves not only water-borne operations but also the ground-based operations of the terminal

and the surface transportation systems that service the port facilities. Thus, ports have snow and

ice removal responsibilities similar to those of other roadway and rail system operations. Heavy

rain can hamper port operations by producing local or widespread flooding, which can also

endanger inland waterway activities, including lock operations, as well as damaging equipment

and cargo.
4-28

Required lead times for information on these weather elements vary by activity, but two time

frames are clearly of most value. The first is the medium range planning time frame, which for

most water-borne activities is 12 hours for freezing and frozen precipitation and 6 hours for rain.

For port operations, 12 hours is the preferred lead time as well, except for heavier snowfall

(greater than 4 inches), when 24 hours is desired. The second lead time period of great value is

0–6 hours. Information requested in this time frame includes current observations (or current

nowcasts) of weather conditions that are affecting operations, as well as forecasts of weather

conditions in the next six hours.

Temperature-Related Elements

Temperature-related activity–elements account for 19 percent of the total for MTS operations. Of

the 36 activity–elements, 11 are for air temperature. Another 20 are for heat index and wind chill

temperature, and 8 are for water temperature and freezing spray. (Freezing spray is actually a

weather-related consequence of winds, seas, and temperature.)

Air and water temperatures have the greatest effect on water-borne operations as they fall to and

below the freezing point. Air temperatures of 32 °F or less cause water that splashes or sprays on

a vessel to freeze. The resulting accumulation of ice on decks, superstructure, and rigging of a

vessel can make it top-heavy and seriously decrease its stability. This condition occurs with a

combination of freezing temperatures, heavy seas (relative to the vessel), and wind, which

together produce large amounts of spray inundating the vessel and accumulating as ice.

Operators of Coast Guard cutters on the Great Lakes cited this as a particular concern. Mitigating

actions include changing direction and speed to reduce the amount of spray, removing ice from

the vessel, and seeking shelter until the conditions abate. Cold temperatures are also a health and

safety risk for personnel and affect the operation of some equipment, requiring that personnel are

properly clothed and equipped and that sensitive equipment is protected.

Inland waterways of the U.S.

Marine Transportation System

play a critical role in the

nation’s commerce. Photo

courtesy NOAA Photo

Library.
4-29

Decreasing water temperatures and formation of ice, particularly on inland freshwater bodies,

affects all vessels from small recreational boats to large ferries and barges. On the Great Lakes,

for example, the Coast Guard removes its small boats from the water and Coast Guard cutters

become the primary search and rescue resource. Coast Guard icebreaking operations then

commence for emergency operations, flood control, and facilitating navigation.

Hot temperatures also affect the safety and effectiveness of personnel. In almost all cases, the

lead time desired is 12 hours for the onset of either cold or hot conditions that affect operations

or safety, whether it be for a cruise liner or recreational boaters. Port operations are the

exception, where the desired lead time is 24 hours to prepare for cold temperatures.

Tropical Cyclones, Sea State, and Ice

This category includes wave height (which has already been discussed as a factor in freezing

spray), storm surge (including abnormally high or low tides), and ice (inland bodies, rivers, and

open seas). Other than the U.S. Navy, none of the users specified tropical cyclones, per se, as an

item of required information. Instead, they specified elements that can occur with tropical

cyclones, such as wave height, high winds, heavy precipitation, thunderstorms, and storm surge.

For the U.S. Navy and operators of other ocean-going vessels, tropical cyclones and even severe

winter storms provide planning and operational challenges, as ships cannot generally ride out

storms in port without sustaining damage. Once they are underway (or "sortie"), ships must steer

well clear of the highest winds and seas to avoid personnel injuries and damage and to ensure

their stability limits are not exceeded. Storms that remain well out to sea are of little consequence

to the general public but of great concern to the Navy. Because of the need to sortie ahead of

tropical cyclones, the Navy must make decisions 3 to 5 days in advance of potentially dangerous

weather. Sortie decisions are significant because of their high cost and impact on personnel and

operations. In making these decisions, Navy fleet commanders must strike a balance between the

risk of staying in port and the cost and potential for damage at sea. Within the continental United

States and adjacent ocean areas, tropical cyclone forecasts in particular are closely coordinated

between Navy forecasters and the NWS.

Storm surge and abnormally high or low tides are of greatest concern to recreational boaters,

ferries, and port operations. The danger is primarily to port and mooring facilities and to vessels

that are moored. For ferries, there is an increased risk of grounding and impaired passenger

accessibility, especially for those with disabilities. The WIST participants generally requested

lead times of 24 hours for response to these weather elements.

Ice poses a threat to all MTS activities due to the risk of hull damage to vessels and damage to

port facilities. Mitigation actions include avoiding areas of ice, navigating ice-bound areas at

speeds and with equipment that permit safe passage, requesting ice breaking services, or ceasing

operations. Lead times requested by participants were generally 12 hours for vessels and 24

hours for port operations. Tailored ice forecasts and analyses are provided by the National Ice

Center, located in Suitland, Maryland. The Navy (through the Naval Ice Center), NOAA, and the

United States Coast Guard jointly operate the National Ice Center, which provides ice analyses

and forecasts to civilian as well as military activities for the Arctic and Antarctic regions, coastal

United States waters, and the Great Lakes.
4-30

Winds

High wind by itself accounts for only 11 of the activity–element combinations identified for this

sector. However, if the wave height element is included with wind (since wave height is a winddriven phenomenon), the activity count doubles to 21 (11 percent of the total count for this

sector). Wind and waves may be the weather elements that most frequently affect a wide range

of waterborne and port operations.

High winds are a concern for all sector activities including marine modeling (which seeks to take

wind effects into account in the models). Small boat handling becomes difficult at about 20 knots

and operators are advised to exercise caution. At about 30 knots and greater, suspension of all

small boat operations is strongly recommended. Ferry and barge operations begin experiencing

difficulty at 20 knots, and by 30 knots operators may find it appropriate to cease operations until

conditions improve. At 45 knots, these operators are likely to experience extreme difficulty with

handling and maintaining control of their vessels. Larger ocean-going vessels are not as affected

by wind speeds less than 30 knots, but when winds are above that speed they, too, begin to

modify their operations to reduce risks to their cargo, passengers, and vessels. Port operations,

which are also affected by high winds, begin to implement mitigation actions when wind speeds

exceed 25 knots. Wind damage is possible to port facilities at speeds above 25 knots and likely at

speeds above 45 knots.

The greatest wind-related effect is increased wave height. Wave heights of 2 to 4 feet affect

passenger comfort and pose some risk to small boats, both inland and on open water. At 4 to 6

feet, there are safety risks for passengers and crew, and small boats should curtail or cease

operations. Ferries and barges are likewise affected and may need to reduce speed or suspend

operations. Waves of this height can also damage port facilities. Coast Guard cutter operations

Ice on the Delaware River

floats in the shipping lanes

near Philadelphia, in

January 2001. Copyright

AP Wide World photos.
4-31

on the Great Lakes are greatly affected by the combination of wind and waves. Indeed, the Coast

Guard reports that each class of cutter reacts differently to different wind speeds, and each Coast

Guard operation is affected differently by winds at a given speed. When wave height reaches 6 to

12 feet, there is risk to passengers, crew, and cargo for medium to small vessels, which should

adjust course and speed to minimize the impact of the seas on the vessel. At this sea state,

damage is likely to port facilities, and ports therefore implement procedures to minimize the

damage where possible. At heights of 10 or 12 feet and greater, there is safety risk to personnel

and risk of structural damage to larger vessels and their cargo. NASA, for example, will consider

delaying movement of its cargo until conditions improve.

Although the Great Lakes do not experience gravitational tides, they do have wind-driven tides

(referred to as “seiching”) that can affect MTS operations. Under the influence of a steady wind,

water is pushed from one end of a lake to the other, leaving behind low water levels that can

prevent vessels from transiting shallows that are normally passable. In addition waves on the

Great Lakes typically have a shorter period than ocean waves do. They can come from various

directions and build rapidly.

For both winds and wave height, the WIST participants reported that they generally require 12

hours lead time for the more moderate conditions that require only increased caution. They

require 24 hours lead time for more serious conditions that hinder or preclude safe vessel

operations.

Visibility

Each sector activity except marine modeling has an activity–element for reduced visibility in

general and another for sun glare, resulting in a total count of 20. The principal impact is

decreased ability to navigate and maintain safe clearance from obstacles and other vessels.

Generally, visibility does not become a factor for MTS operations until it decreases to 3 miles or

less. At that point, most activities simply slow down and exercise more caution. Some take more

specific actions. NASA, for example, does not allow movement of cargo when visibility drops

below one-eighth of a mile. Most of the users require only 6 hours lead time for reduced

visibility conditions; however, NASA needs 24 hours.

Thunderstorm-Related Elements

Thunderstorms and related weather phenomena account for 17 of the activity–elements for the

MTS sector. Although these phenomena can be very severe and cause loss of life and property,

they generally affect smaller areas for shorter periods of time than do some other weather

elements. When severe thunderstorms do occur in the vicinity of MTS operations, all the sector

activities recognize the potential risks to people, vessels, and cargo. The range of mitigation

actions is similar; most activities cease outdoor operations in the vicinity of the threatening

weather. Vessels underway take evasive actions as necessary.

Lightning is the most common risk. When lightning is present, small boats will generally cease

operations and most users will cease hazardous activities such as refueling. Hail may damage

cargo or equipment and injure personnel. Heavy rain and wind reduce visibility, requiring extra

caution and reduced vessel speeds. Protective actions include keeping vessels and people out of
4-32

the severe weather as much as feasible and curtailing outside activities when possible. For

example, NASA will delay, reschedule, or reroute water-borne transport of spacecraft, vehicles,

and equipment as appropriate to protect people from injury and prevent damage to very sensitive,

high-value space program equipment.

The most severe risk is from tornadoes (primarily to inland waterway operations) and some

extreme waterspouts. Although this risk is far less frequent than thunderstorms with lightning,

tornadoes pose a severe threat to life and property. The preferred mitigation action is to adjust

course and speed to avoid the severe storm. In almost all cases for thunderstorm-related weather,

the desired lead time is 3 hours, with real-time updates when storms are actually occurring and

affecting operations.

Miscellaneous Elements

The miscellaneous group contains several weather elements of particular interest to WIST users

in the MTS sector. One is the element for atmospheric dispersion from release of a nuclear,

biological, or chemical hazard. Such events are health and environmental risks, as well as being

potentially life threatening. The mitigating action in almost all cases is to cease operations and

clear (or avoid) the area. A related element is air quality. Poor air quality can pose a health risk

to personnel. Both of these elements were designated as relevant to ten sector activities (all

except marine modeling).

Space weather is a third element in this group that was designated as relevant to the ten sector

activities except marine modeling. As the MTS becomes increasingly dependent on modern

communications, navigation, and data transfer systems, there is a corresponding need to monitor

and manage these electronics-dependent systems for any adverse effects of heightened solar

weather activity.

Every day, the Port of Baltimore

handles tons of coal, hundreds

of foreign-built cars, and

thousands of boxcar-sized

containers. Hazardous material

incidents, including deliberate

releases of nuclear, biological,

or chemical hazards, are among

the emergencies for which

managers of this complex

intermodal transportation node

must prepare. Copyright AP

Wide World Photos.
4-33

The fourth miscellaneous element designated as important to ten of the sector activities is

volcanic ash. Volcanic ash can damage equipment, present a health risk, and reduce visibility.

Mitigating actions include protecting equipment, clearing the ash, providing breathing equipment

for personnel, and curtailing operations in the vicinity of an ash plume.

Finally, although not explicitly designated by the participants from this sector, the element of

“correctly forecasting fair weather” is also important to the MTS. Many sector activities rely on

good weather for efficiency and, in some cases such as recreational boating, safety and

feasibility. Therefore, accurate forecasts of good weather can be as valuable to activities in this

transportation sector as a forecast for adverse weather.

4.6 Pipeline Systems Sector

Pipeline operations can be divided into two distinct areas of

responsibility: the pipeline industry itself and the users of

pipeline delivery services. The pipeline industry can be

viewed as the “highway system” for commodities

transported through long-distance pipelines. These pipelines control the transport of immense

quantities of fluids (gases and liquids) across the United States to support our economic system’s

requirements for on-time delivery of supply to meet demand. This critical function is maintained

and managed at control centers operated by the individual pipeline companies. A control center

is the focal point for all gathering and distribution of information relevant to a pipeline’s

operation and status. The control center monitors and controls the complete length of pipeline. It

receives measurement data on flows, pressures, and temperatures and remotely controls valves

and limited holding tanks. Relative to the volumes being transported in a unit of time, pipeline

companies have little or no holding capacity for the transported fluids at either end of the line.

Thus the product providers, for example an oil refiner or a natural gas supplier, are responsible

for most storage, usually in the form of tank farms. The product providers are also responsible

for well-head operations, tank farm pipeline distribution, local pumping stations, and maritime

tanker distribution operations.

Pipelines are essentially product

“highways.”

The Trans Alaska Pipeline

carries crude oil from

Northern Slope oilfields 800

miles to the ice-free port of

Valdez, Alaska. Photo

courtesy Office of Pipeline

Safety, U.S. Department of

Transportation.
4-34

4.6.1 Sector Activities

Weather-sensitive activities or operations related to pipeline system operations generally fall into

one of more of the categories shown in Table 4-5. These nine activities are used in the WIST

needs template for this sector (Appendix B-4) to define activity–element combinations.

Table 4-5 Sector Activities for Pipeline Systems Sector

4.6.2 Analysis of Activity–Elements

The pipeline system sector of transportation had the smallest participant population in the WIST

needs study, with inputs received from 15 separate agencies or entities. These participants

identified 19 distinct weather elements that affect their activities and for which weather

information could aid in mitigation actions. Figure 4-9 shows the distribution of the 128 activity–

element combinations in the Pipeline Systems template among the weather element groups. Of

these groups, precipitation had the highest count of activity–elements, followed by the tropical

cyclone–sea state–ice group and the temperature-related group.

Even though a pipeline system, including the well heads, valves, tanks, etc., as well as the

pipeline itself, completely encloses the material that is moving (the product flowing through the

pipe), weather does affect the system’s safe, economical, and efficient operation. Weather affects

the complete spectrum of pipeline operations; including all of the sector activities listed above.

However, for the weather element groups with the highest counts of activity–elements in the

template, it is the secondary phenomena caused by precipitation, temperature extremes, or high

winds that are of direct concern. Specific conditions cited by the WIST participants as major

threats to sector activities include flooding, seabed scouring, landslides, and frost heave. These

and other consequences of weather and environmental phenomena comprise the second largest

contributor to pipeline damage or failure.

Control center operations. Operations to monitor the pipeline system, advise system operators, and control

system integrity.

Pumping station operations. Responsible for fuel movement, allocation, storage, and distribution.

Well head/drill site operations. Includes operations for fuel pumping, storage, and distribution near source

wells.

Tank farm operations. Includes fuel storage, distribution, and maintenance at tank farms.

Construction. Operations include construction, maintenance, and repair, as well as the scheduling of these

operations.

Hazardous material. Includes monitoring storage and transport of hazardous materials and any mitigation,

reclamation, and reporting operations associated with their accidental release while within the pipeline

system.

Surveillance. Includes inspections, monitoring, and maintenance.

Personnel safety. Any operation where safety and health risks to workers or others may be present.

Fuel barge operations. Includes barge docking, fuel movement by barge, and transfer to/from fuel barges.
4-35

In the initial WIST survey conducted in 2000, prior to preparation of the WIST needs templates,

precipitation elements were of interest to 80 percent of the respondents for this sector. Flooding,

visibility, and winds were weather elements of interest to half or more of the respondents.

4.6.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on pipeline system

operations and the response actions that the WIST study participants identified as potentially

influenced by accurate information on each element. Mitigation actions can range from simply

increasing awareness to taking specific corrective actions or curtailing or suspending activities.

All these actions are intended to avoid unnecessary cost, damage to property, or safety risk to

people. As discussed in Section 4.2, weather impacts can be mitigated or obviated to varying

degrees by timely action, and response decisions are affected by many factors other than weather

information.

Precipitation Elements

Precipitation in its several forms, including freezing or frozen (ice and snow) and liquid

precipitation (heavy rain, flooding), is the weather element group with the highest count of

activity–elements (36, or 28 percent of the total) in the WIST needs template for pipeline system

operations. Accumulations of ice and snow can freeze valves, rendering them inoperative. Ice

and snow removal may damage valves and gauges, and pipeline sensors are more likely to fail.

Consequent disruptions of product delivery may require emergency fuel management

procedures; re-allocation, transfer delays, re-routing, or unscheduled storage. Disruption of

construction or maintenance cycles may result. Leaks or other pipeline failures are possible,

which may require implementing procedures for HAZMAT incident response. Safety of

personnel and equipment is critical, requiring proper clothing and increased monitoring of crews

and equipment because accidents are more likely in icy conditions. Inspections of buried pipeline

by digging an inspection trench or bore hole may be complicated by ice, snow, and frozen soil.

Delays in scheduled construction and inspections are likely. During ice and snow storms,

Figure 4-9 Pipeline systems activity-elements by weather group.

28%

6% 5% 5%

18%

21%

16%

0%

5%

10%

15%

20%

25%

30%

Precipitation

Thunderstorm

Related

Wind

Visibility

Temperature

Related

Tropical

Cyclone, Sea

State, Ice

Miscellaneous

Activity-Element Count
4-36

telephone communications by satellite, radio, or cellular wireless networks may be disrupted,

and data collection from pipeline sensors may fail. Any of these physical consequences may also

impact public relations of the pipeline operator, the product provider, and any regulatory or

oversight agencies involved with them.

In addition to the impacts listed for freezing or frozen precipitation, heavy rain and flooding may

scour pipeline roadbeds and unearth buried pipelines. The pipeline can also be damaged by line

stretch and impacts of foreign objects and debris. Direct inspection of buried pipeline sections

may be complicated by standing water.

Mitigation actions for precipitation above threshold values for the type of precipitation include

increased visual inspections and remote monitoring. Control centers will issue advisories and/or

warnings to other pipeline activities (see

Table 4-5). Fuel management contingency plans (re-route, store, cancel

transfers, etc.) may be initiated. Control

centers may issue communication

advisories, all operations report

communication failures and monitor

outages, and alternative modes of

communication may be implemented,

such as backup plans for collecting and

distributing pipeline sensor data.

The integrity of pipelines, tanks, and

valves is checked, the liquid level in

tanks is checked, and tank contents may

need to be sampled and analyzed for

homogeneity and purity. Inspections of

floating tank roofs, sumps, and water

impounds may be needed, and these

structures may need to be drained or

pumped out if heavy rain or snow melt

is anticipated. Additional crews or crew

assignments may be required. The

pipeline scheduler can make arrangements with product providers and terminals or customers to

accommodate a schedule disruption. For longer lasting or more severe conditions, any work that

can wait until the weather clears is postponed and alternate construction and maintenance

schedules are developed. Aerial and vehicle pipeline inspections are rescheduled, restricted, or

suspended based on weather safety.

Crews dig around a buried portion of the Trans

Alaska Pipeline in search of an underground leak.

Although pipelines are often underground, weather–

related conditions are the second-most frequent

contributor to pipeline damage or failure. Copyright

AP Wide World Photos.
4-37

For freezing or frozen precipitation, de-icing, anti-icing, or snow removal programs may be

initiated for roads, walkways, valves, gauges, etc. Crews are required to wear proper clothing

and footwear for icy or slick conditions. If a pipeline is breached or other leakage occurs,

HAZMAT spill reaction and mitigation plans must be implemented and proper authorities

notified. If flooding is forecast or observed, additional inspections of bridges, trestles, and

pipeline roadbed for structural integrity may be included in the pipeline inspection procedure.

Tropical Cyclones, Sea State, and Ice

This weather group accounted for 21 percent of the total activity–element count for the pipelines

sector. The impacts on pipeline systems are, like those associated with flooding, primarily risks

of physical damage to the infrastructure, with potential secondary consequences such as

HAZMAT incidents and personnel safety.

Pipeline roadbed may be scoured by flooding, and buried pipeline may be unearthed and

damaged or destroyed. Seafloor pipeline may be damaged or destroyed. These conditions

increase the risks of pipeline damage from line stretch, foreign debris impact, and corrosion from

damaged coating. Pumping may be restricted or suspended. Pipeline sensor failure is more likely.

High winds, seas, and tides restrict or suspend movement of barge traffic between offshore drill

sites and coastal pumping facilities. Disruption of fuel delivery may require emergency fuel

management procedures, including re-allocation, transfer delays, re-routing, or unscheduled

storage. Construction and maintenance cycles may be disrupted. Leaks or other containment

failures may require HAZMAT procedures.

Mitigation actions begin with increased pipeline and infrastructure surveillance, including visual

inspections and remote monitoring. Additional inspections of bridges, trestles, and pipeline

roadbed for structural integrity may be included in the pipeline inspection procedure. The

integrity of pipelines, tanks, and valves is checked, the liquid level in tanks is checked, and tank

contents may need to be sampled and analyzed for homogeneity and purity. Additional crews or

crew assignments may be required. Any work that can wait until the weather clears is postponed,

and alternate construction and maintenance schedules are developed.

Control centers need hurricane advisories and warnings prior to and during barge operations,

tank construction, maintenance, or repair. They will issue advisories or warnings to other

pipeline system activities and product providers. If conditions become unsafe at the control

center, controllers evacuate the building and go to a strategic backup site. This site is already set

up to allow the controllers to monitor and operate the pipelines. The pipeline scheduler will make

arrangements with product providers and terminals or customers to accommodate schedule

disruptions. Pipelines may be drained or filled, as appropriate to decrease damage susceptibility.

If high winds and heavy precipitation are involved, aerial and vehicle pipeline inspections are

rescheduled, restricted, or suspended, based on safety, as are fueling operations. If a pipeline is

breached or other leakage occurs, HAZMAT spill reaction/mitigation plans must be implemented

and proper authorities notified.
4-38

Temperature-Related Elements

Temperature-related activity–elements constitute 18 percent of the total for the pipeline sector.

Soil temperature affects eight of the sector activities. Air temperature (four activity–elements)

and heating/cooling degree days are also important for potential impacts on the pipeline

infrastructure (five and four activity–elements, respectively). Wind chill and heat index are

important primarily for health and safety risks to personnel working outside.

For soil temperature, the principal concern is temperatures below freezing or oscillating around

the freezing point. These conditions can produce ground heave, resulting in pipeline motion or

movement. Ground heave is most prevalent during the autumn freeze and the spring thaw.

Inspections of buried pipelines by digging out an inspection trench or boring may be complicated

or delayed by frozen soil. Construction and maintenance delays may also occur.

When the air temperature drops to freezing and below, especially if moisture is present from

precipitation, many of the same impacts can occur as are discussed above for freezing

precipitation. When the air temperature drops below -20 °F or increases above 100 °F, there are

sanctions and prohibitions against the use of plastic pipe.

Mitigation actions for the soil and air temperature elements include most of the non–weatherspecific actions listed above for precipitation. Control centers will issue advisories and/or

warnings to other sector activities and may schedule additional system inspections and

monitoring. Fuel management contingency plans (re-route, store, cancel transfers, etc.) may be

initiated. Additional crews or crew assignments may be required. The integrity of pipelines,

tanks, and valves may need additional checking, as may the liquid level in tanks. Tank contents

may need to be sampled and analyzed for homogeneity and purity. If a pipeline is breached or

other leakage occurs, HAZMAT spill reaction/mitigation plans must be implemented and proper

authorities notified.

Fuel demand can vary dramatically, depending on the heating or cooling degree days. Thus, this

weather element can have major impact on regional and national fuels distribution by pipelines.

Accurate forecasts help pipeline operators prepare for changes in demand and help product

preparers in readying appropriate quantities of fuels formulated for different regions.

Wind and Visibility

Taken together, wind and visibility elements make up about 10 percent of the total count of

activity–elements for the pipeline sector. Visibility of less than one-fourth of a mile restricts or

suspends movement of barges and tankers to and from offshore drilling sites and coastal

pumping facilities. Reduced visibility also restricts or suspends the safe surveillance of the

pipeline by air or truck, disrupts construction and maintenance operations, may cause pumping to

be restricted or suspended, and affects the safety of personnel and equipment.

Wind speeds above 60 mph, particularly in coastal areas, restrict barge and tanker operations,

may disrupt fuel deliveries, may cause pumping to be suspended, and may disrupt construction

and maintenance schedules. In addition, high winds may cause physical damage to the pipeline

system, especially if the wind is associated with heavy seas or inland flooding and severe storms.
4-39

Damage can result from debris impact or from scouring or erosion of the pipeline roadbed by

water and wave action, particularly for underwater pipelines.

The pipeline system operators generally want 12 hours lead-time for these weather events.

Mitigation actions, which are similar to those for flooding or high seas, include increased

inspections for integrity of pipelines, tanks, and valves, as well as for bridges, trestles, and

pipeline roadbed. Maintenance and construction may be rescheduled, and fueling operations may

be suspended. If deliveries are disrupted, fuel management contingency plans may have to be

implemented.

Thunderstorm-Related Elements

This weather element group includes only 6 percent of the activity–elements. The count may be

misleading because three separate weather elements—tornadoes, hail, and lightning—were

reported together with thunderstorms as a single weather element. Nevertheless, all of the

pipeline system activities are impacted by one or more of these severe weather elements, with

tornadoes and lightning being the most significant. Both can result in injury to personnel and

damage to equipment. In addition, lightning can damage or destroy pipeline sensors and disrupt

data flow and communications from both sensors and control facilities. Pipeline operators desire

forecasts and warnings of these conditions 6 hours in advance.

Mitigation actions primarily involve delaying or terminating outdoor activities such as fueling

and construction. In the vicinity of severe storms, there may be additional inspections of the

pipeline system required, after the storm has passed. Contingency plans may need to be

implemented for loss of sensor data, physical damage, or disruption of the flow, as well as

response to any HAZMAT incident that may occur.

Miscellaneous Elements

For pipeline systems, the two largest counts of activity–elements from the miscellaneous group

are for earthquakes and space weather, with 8 sector activities potentially impacted by each. The

importance of these elements reflects the susceptibility of buried pipelines to ground movement

and the dependence of pipeline system operations on communications linkages that may be

susceptible to the electromagnetic disturbances resulting from solar storms.

The impacts of seismic activity are much the same as those related to flooding or tropical

cyclones (hurricanes). Primary impacts include roadbed scouring; buried pipe being unearthed,

damaged or destroyed; disruption of fuel delivery; pipeline sensor failure; leaks or other pipeline

failures; and, of course, the safety of personnel and equipment. The mitigation actions are similar

to those cited above for flooding or tropical cyclone conditions.
4-40

Space weather affects all pipeline activities because of the impact it can have on communications

(especially satellite, radio and cell phones) and data distribution from pipeline sensors. Remote

sensors may detect a leak or pipeline failure, but the communications link to relay the

information to the pumping station, tank farm, or control center may be temporarily lost or

physically damaged. The control centers monitor communications outages, make use of

alternative modes of communication, and execute backup plans for sensor data distribution.

Two other elements, air quality and atmospheric transport and diffusion of hazardous substances,

are issues of concern to control centers and personnel at any operation (the “personnel safety”

sector activity). In the event of a leak or pipeline failure, vapors and toxins are released to the

environment with possible catastrophic results. The control centers ensure the proper authorities

are notified and advisories and warnings are issued, work schedules are revised, the HAZMAT

spill reaction and mitigation plan is implemented as necessary, and relevant inspections are

conducted to ensure the integrity of the pipeline system.

4.7 Rural and Urban Transit Sector

Weather impacts on transit operations are often significant. When a weather event is extreme, it

can be the most important factor in satisfying or not satisfying the transit mission. Transit

systems often experience increased ridership when snowstorms or other severe weather induce

mode shift. Thus, even as weather conditions are complicating operations, transit systems must

be prepared to meet these surges in demand through increased staffing and deployment of

standby equipment (buses, railcars, vans.).

One of the principal goals of transit officials is to provide early and understandable weather

information products and services to transit customers, as well as to surface transportation

professionals. A key aspect of the WIST problem identified by the transit officials in this study is

the current limitations on acquiring reasonable, physically consistent weather data at small

scales. This user issue underscores the importance of mesoscale and misoscale variations that

Forest fires are a potential

threat to above-ground

pipelines. Copyright AP

Wide World Photos.
4-41

greatly impact the transit sector. Transit authorities need WIST suppliers to provide tailored,

detailed, and accurate forecasts with lead times of 12 to 24 hours.

4.7.1 Sector Activities

Table 4-6 defines the operations and transportation activities used in the WIST needs template

for rural and urban transit operations (Appendix B-5). The weather sensitivities of transit systems

generally parallel those for buses and roadway maintenance operations in the roadway sector and

for station and depot operations, railway/control center operations, and personnel safety in the

long-haul railway sector. However, in this sector the railway activity is primarily aimed at

passenger transport, with commuter schedules (e.g., dealing with morning and evening peak

loads) being a major concern. Another sector activity with some unique sensitivities is school

transportation.

Table 4-6 Sector Activities for Rural and Urban Transit Operations

Transit passengers wait for

their bus to arrive. The safety

of passengers waiting at stops

is a major concern of transit

system managers. Copyright

AP Wide World Photos.

Roadway maintenance. This activity includes roadway surface treatment for snow and ice control in the

winter, as well as maintenance to repair damage to roads and infrastructure.

Bus operations. In addition to bus driving, this activity includes road supervision and maintenance of the

bus fleet, terminals and other facilities, and bus stops.

Trolley bus. This activity refers primarily to electric trolleys with overhead wires.

School transportation. This activity includes transportation of students by bus and commuting to school by

young, inexperienced drivers.

Rail operations. This activity includes passenger rail operations above and below ground, and station and

platform areas. Trains are predominantly electric, using a power rail (“third rail”) or overhead wires.

Traffic management. Activity consists primarily of managing traffic signals and traffic routing to enhance

safety and efficiency.
4-42

4.7.2 Analysis of Activity–Elements

The transit sector was represented by the largest population of study participants (60). With 141

activity–elements identified by its study participants, the transit sector has the third highest

activity–element count of the study. (The roadways sector has the same number of distinct

weather elements, 52, and the MTS sector has only 35, but both have a greater number of sector

activities affected, resulting in more activity–element combinations.)

Figure 4-10 shows the percentages of Transit activity–elements from the WIST needs template in

each weather element group, as defined in Table 2-1. The precipitation group, with 45 activity–

elements, has the largest fraction (32 percent). Temperature-related activity–elements constitute

the next highest group, with 30 activity–element combinations (21 percent). For comparison, the

roadway and long-haul rail sectors had only 28 percent and 27 percent, respectively, of their

activity–elements in the precipitation group, but higher percentages than transit in the

temperature-related group (23 percent and 29 percent, respectively).

In the initial WIST survey in

2000, which preceded the

needs templates, precipitation was the general weather

condition most frequently

cited by transit sector

participants as one for

which they needed

information. Nearly 90

percent of the 78

respondents from this sector

indicated a need for

precipitation information.

Winds, flooding, visibility,

temperatures, and thunderstorms were identified by

half or more of these respondents as weather conditions on which they needed information.

4.7.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on transit operations and

the response actions that the study participants identified as potentially influenced by accurate

information on each element. Mitigation actions can range from simply increasing awareness to

taking specific corrective actions or curtailing or suspending activities. All these actions are

intended to avoid unnecessary cost, damage to property, or safety risk to people. As discussed in

Section 4.2, weather impacts can be mitigated or obviated to varying degrees by timely action,

and response decisions are affected by many factors other than weather information.

Decisions not within the control of transit system managers can undo a transportation decision

reasonably based on an accurate weather forecast. For example, businesses or agencies

Figure 4-10 Transit activity-elements by weather group.

32%

13%

4%

7%

21%

5%

18%

0%

5%

10%

15%

20%

25%

30%

35%

Preciptation

Thunderstorm Related

Wind

Visibility

Temperature

Related

Tropical

Cyclone, Sea

State, Ice

Miscellaneous
4-43

sometimes release their employees in mid-day when snow begins to fall, without regard to the

regularly scheduled public transportation slow-down between the morning and afternoon rush

hours. This action creates a tremendous surge in demand for public transit services just when the

system’s capability is at a minimum, resulting in delays and overcrowding.

As noted in the discussion of the roadway sector, state police organizations that participated in

the WIST survey indicated that knowledge of the local effects and variability of weather

conditions gives their troopers an advantage in performing their duties. This knowledge, coupled

with accurate and timely weather forecasts, improves the ability of all police agencies to refine

staffing and enforce traffic control more effectively. Often, the police are the first on-scene

weather observers, and this information can be relayed to transit command centers for

redistribution. Some states (for example, the Minnesota Department of Transportation) even

have observing systems on board their vehicles. These systems communicate directly to a traffic

control center for immediate distribution and input to traffic control decision systems.

Monitoring the environment in a proactive manner can increase public safety and help both the

police and transit activities achieve their transportation missions despite adverse conditions.

Precipitation Elements

Precipitation, especially freezing or frozen precipitation (ice and snow), causes the greatest

impacts for the roadway sector. Most of the activities list safety and health risks to people and

property damage risks as potential consequences of any freezing precipitation. Almost all list

similar risks for frozen precipitation (snow) as well, with the risks increasing as snow depth

increases. Road maintenance activities are most concerned with freezing and frozen precipitation

because these conditions typically cause the greatest expenditure of resources in areas where

such precipitation occurs. They have the most impact on public safety, other than perhaps a

major hurricane. Ice or snow on the roadways mean loss of traction, stability and

maneuverability; impaired mobility; roadway obstructions; loss of control; and increased

occurrence of vehicle mishaps, with attendant injuries and risks to life and property. For almost

all users, it means probable schedule and travel delays.

The first snowstorm of the season

slows the morning school bus

commute on I-35W near

Minneapolis. School superintendents

rely on timely and accurate weather

information to make the right

decisions regarding school closing or

delayed opening. Copyrignt AP Wide

World Photos.
4-44

In addition to impediments to safe travel resulting directly from ice or snow, bus operations are

hampered by traffic congestion and accidents, delays of operations, and routes that require

detours. The risk of damage to buses increases, and inclement weather causes delays in

maintenance of facilities, the bus fleet, and bus stops. Operators are advised to drive with

extreme caution. Operations are modified, restricted, or suspended as necessary, especially on

hills. Trolley buses face the additional complication of ice on overhead electric wires, which can

cause malfunctions that disrupt operations. At the onset of precipitation, they can be equipped

with ice cutters to keep the wires clear of ice.

School systems are concerned not only with large numbers of school buses but also with large

numbers of young, inexperienced drivers who may have never driven before in adverse weather

conditions. The mitigation options include deciding to close schools prior to opening for the day,

delaying opening of schools in the morning, or dismissing early if school is already in session.

School officials who participated in the WIST study underscored the critical importance for this

decision process of accurate local weather forecasts with sufficient lead times.

Rail operations face similar difficulties. Ice buildup on the third rail or catenary lines (overhead

wires) causes power outages for trains. The risk of mishaps increases when ice builds up on the

rails, affecting braking action, and on the platforms where personnel safety is the issue. Delays

occur as trains operate at slower speeds for safety reasons. Mitigation actions include inspecting

and clearing ice buildup from rails and overhead wires, using ice scrapers and snow brakes on

the trains, running service vehicles or snow trains to keep the tracks and overhead wires clear,

activating heaters in the third rail and switches, removing ice from platforms and parking lots,

and, as a last resort, restricting or suspending operations as necessary.

The lead times these users require for information on winter precipitation events vary by activity,

but two time frames stand out. The first is a longer range planning time frame, which varies by

activity as follows:

Winter storms increase

the risks of track signal

malfunctions. Here, a

passenger transit train

has collided with an

inter-city passenger train

using the same rail line

during a winter storm in

Maryland. Copyright AP

Wide World Photos.
4-45

• 12 hours for school administrations (allowing them to make decisions and disseminate

the information to the public and employees)

• 12–24 hours for bus operations

• 24 hours for train operations

• 24–48 hours for road maintenance operations (allowing preparations to begin, prediction

of the threatened area, selection of treatment strategy, and preparation and deployment of

treatment assets).

The second lead time window of major value extends roughly from 0 to 6 hours before

precipitation begins. This corresponds to the execution phase of mitigation actions planned

earlier. For road maintenance crews, this means final decisions and initial operations to treat and

clear roads of snow, ice and debris; deployment of treatment crews and assets; and initiating

changes in traffic flow management. This phase makes use of current observations, as well as

near-term forecasts and nowcasts.

Liquid precipitation affects most transit sector activities less than frozen or freezing precipitation

does, unless it is heavy precipitation. Road maintenance operations are an exception because of

concerns with traction, road submersion, drainage, and reduced visibility. The impact threshold

for this activity is any liquid precipitation at all.

Conditions that produce flooding of any sort are of concern to all transit activities. Local

knowledge of flooding is critical to transit operations, especially where low-lying underpasses

are affected. The local transit authorities know where flooding tends to occur; but they also need

to know when a weather event will generate sufficient precipitation (intensity and duration) to

produce flooding. For most activities, the lead times desired by decision makers for forecast of

flood conditions range from 12 to 24 hours. The lead time and format of information must be

adequate to convey the information to the traveling public efficiently and effectively.

Mitigation actions for flooding vary by sector activity. Buses may be rerouted, diverted, taken

out of service, or used to help evacuate people from flood-prone areas. If not in use, they may

need to be moved to high ground. Rail transit operators may need to suspend or reroute service

through areas that are likely to flood or are already flooded. After the flooding has receded, they

must clear rails and wires and inspect and repair track, roadbed, bridges, and culverts.

Temperature-Related Elements

Most of the temperature-related activity–elements in the transit sector come from the road

maintenance community. Of the 30 activity–elements in this group, 11 are for air temperature

(including maximum and minimum temperature, temperature relative to freezing with rising or

falling trend, temperature change rate, and degree cooling/heating days). Another 8 are for heat

index and wind chill temperature. Six are for pavement, subsurface, and rail temperatures.

Road maintenance operations for this sector, as for the roadway sector, depend on temperature

information, particularly the combination of pavement temperature and air temperature with

rising or falling trend. Accurate temperature information, coupled with precipitation information,
4-46

allows maintenance managers to select the correct strategy and material to treat road surfaces to

minimize the effects of winter weather on vehicle traction and traffic flow.

In most cases, the mitigation actions in response to temperature extremes include advising

operators, transit customers, and the driving public, as well as modifying or restricting nonessential operations as necessary. Transit bus operators normally do not curtail operations during

extremes of temperature because of concern for passengers waiting at bus stops and the need to

minimize their exposure time. During extreme cold temperatures, public transit buses may be

used to transport homeless persons to shelters.

High temperatures, as well as low extremes, are a weather concern for transit operators, private

vehicle drivers, and transit passengers. High temperatures require that work crews take

precautions for their own safety and to prevent damage to equipment. They also pose risks for

vehicles. High pavement temperatures increase the risk of tire blow-outs for heavy loads. Rail

operations are particularly affected by air temperatures above 85 °F, as rails will then expand

enough to kink and older catenary wires will sag. Rail operators must increase the frequency of

rail inspections and reduce train speeds under these conditions.

Thunderstorm-Related Elements

Although the impacts of some of the phenomena associated with thunderstorms can be very

severe, including loss of life and damage to property, they generally affect smaller areas and for

shorter durations than do some other weather elements. When severe thunderstorms do occur, all

the transit activities recognize the potential risks to their personnel, passengers, students, vehicles

and vehicle drivers, and equipment, as well as indirect consequences from loss of power or

communications, impeded mobility, and increased traffic congestion. The protective actions are

similar: most activities cease outdoor operations (particularly such things as refueling and

maintenance) in the path of the threatening weather and take evasive actions as necessary. Road

maintenance activities try to predict where the threatened areas will be, prepare to implement

warning and evacuation plans, then respond to roads blocked or damaged by debris. Transit bus

operations normally are not suspended because of concern for passengers waiting at exposed bus

stops. School transportation officials may implement schedule changes to prevent exposure of

students who are in transit between school and home.

Visibility

Visibility and sun glare are the two elements in this group, with five activity–elements apiece.

Reduced visibility from air-borne obscurants (e.g., fog, smoke, precipitation, dust) is not a

concern until visibility decreases to a quarter-mile or less. At that point, safety is affected and

road vehicles simply slow down and exercise more caution. These mitigation actions introduce

schedule delays and increase congestion. Visibility thresholds for rail operations vary, depending

on factors such as the length of a train, the degree of cab control, and operator difficulty in

monitoring signals and switch alignments. Thus, visibility thresholds for transit rail operations

vary from a quarter-mile up to 3 miles. For sun glare, the standard mitigation action for transit

activities is to reduce speed.
4-47

Winds

High winds are a concern to all transit activities. The critical thresholds for most activities are 30

mph for moderate risk and 50 mph for severe risk and significant impact to safety and transit

operations. High winds produce roadway debris, flying debris, downed live electric lines and

poles, traffic slowdowns and congestion, operational delays, and drifting snow in winter.

Maintenance of vehicles, facilities, and bus stops may be suspended or postponed. Mitigation

actions include prepositioning barriers to debris or snow (such as snow fences in the winter);

advising transit operators, passengers, and the driving public; and implementing detours where

necessary. Operations and traffic patterns may be modified, particularly to allow for removal of

debris or drifted snow. Rail operators slow their trains and, when winds reach 70 mph, suspend

service over bridges.

Miscellaneous Elements

Several of the weather elements and weather-related phenomena in the miscellaneous group are

worth noting for their impact on transit activities. Among these are tropical cyclones and the

associated storm surge. A number of weather conditions associated with a tropical cyclone

(wind, rain, reduced visibility, and tornadoes) affect all surface transportation activities in the

area where a storm occurs. Storm surge may affect the coastal area where a storm makes landfall.

The mitigation action includes suspending travel or vacating the area. Road maintenance

activities mobilize maintenance forces for disaster response and damage repair. Transit bus

systems prepare to assist in evacuations and other emergency preparedness actions. The leadtime required for adequate preparation and implementation of these actions can be up to 72

hours.

Another element in this category is weather information relevant to incidents of release and

atmospheric dispersion of nuclear, biological or chemical hazards. These events are lifethreatening, and the responses by transit activities are either to cease operations and clear the

area or participate as part of a previously trained response team. A related element, albeit less

critical in potential health effects, is air quality, which typically has the greatest impact in urban

The Staten Island Ferry moves

through New York Harbor in

the fog. On February 21, 1996,

one of the ferries collided with

the pier while docking in

heavy fog. Copyright AP

Wide World Photos.
4-48

areas. Many of the meteorological conditions that influence the movement of a plume from a

hazardous-materials release are also of importance in forecasting air quality conditions and the

areas affected.

A third element of special interest in the miscellaneous group is space weather. As transit

systems become increasingly dependent on electronic and wireless systems for communication,

navigation, and data transfer, the need increases to monitor and manage system components that

can be temporarily disrupted or permanently damaged by space weather hazards.

4.8 Airport Ground Operations

The assessment of weather information needs for airport ground operations is a small but critical

piece of an overall assessment of how weather elements affect surface transportation and what

information can be useful in improving actions to deal with these weather impacts. Airport

ground operations constitute the interface between other surface transportation modes and the

airborne movement of people and cargo. Weather information support for the multimodal

operations that occur at or near this interface is critical because the effectiveness, efficiency, and

safety of these airport ground operations bear directly and substantially on the overall throughput

of aircraft, passengers, and cargo (the capacity of the air transportation system). This support is

also critical to the timeliness of air transport of both goods and travelers. The weather impacts

and the general types of mitigation responses available to sector operations are more like those of

other surface transportation modes (for example, urban transit operations or port operations of

the MTS) than the weather concerns of aircraft in flight. It is therefore reasonable to include

consideration of airport ground operations as a distinct transportation sector in a WIST study.

Airport ground operations

include wing de-icing prior to

takeoff, as well as all ramp

operations and passenger ground

traffic. Copyright AP Wide

World Photos.
4-49

4.8.1 Sector Activities

This transportation sector includes airport operations on the ground but not flight operations,

since the latter are relevant to aviation weather support rather than weather information for

surface transportation. The sector does include factors that affect the ability of people to get to

and from the airport, as well as ground traffic on the airfield, between aircraft and airport

facilities. The sector activities used in the WIST needs template for airport ground operations

(Appendix B-6) are listed and defined in Table 4-7.

4.8.2 Analysis of Activity–Elements

The airport ground operations sector had the second smallest population of participants in the

WIST study; responses were received from 27 agencies or entities. These participants identified

nine weather elements as affecting the sector activities listed in Table 4-7.

Table 4-7 Sector Activities for Airport Ground Operations

Development of the WIST needs template for this sector, like the efforts for the other sectors,

involved identifying the weather elements of concern to participants, the threshold(s) at which

each element becomes significant to sector activities, and the activities most affected by each

element. For each activity–element combination, the template includes impacts when an element

occurs and the mitigation actions available, if accurate weather information with sufficient lead

time is in the hands of activity decision makers. The participants were also asked to specify the

lead times desired, if a weather warning or weather advisory for a specific weather element were

to be most useful and effective for the impacted activities.

More than 20 civilian airports, 4 major airlines, and 2 military airfields were contacted; each

provided a response useful in developing the sector’s WIST template. In addition, the Federal

Aviation Administration (FAA) identified five key weather-related areas that affect airport

ground operations:

• Snow removal

• Aircraft de-icing operations

• Aircraft refueling operations

• Equipment protection

Aircraft movement. Includes all ground movement of aircraft and safety of flight considerations that

affect aircraft ground movement.

Vehicle movement. Vehicle movement and traffic flow on the airfield and on approaches to the airfield

Gate accessibility. Includes operations for the transfer of baggage and cargo and general aircraft servicing

(cleaning, catering, minor maintenance) while an aircraft is parked at a gate.

Aircraft maintenance. All ground maintenance conducted away from the gate.

Refueling aircraft. Includes transportation of fuels from at-airport storage to aircraft and the operations

during transfer from fuel truck to aircraft fuel tanks.

Foot traffic. All pedestrian movement on the airfield.

Construction and maintenance projects. All vehicular movement and operations related to construction

or structural maintenance of airport and airfield facilities, while the airport continues to operate.
4-50

• Ground support personnel effectiveness.

Figure 4-11 shows the distribution among weather element groups of the 38 activity–element

combinations in the WIST needs template for airport ground operations. The precipitation group

has 15 activity–elements, providing 39 percent of the total. The temperature-related and

thunderstorm-related groups account for 8 activity–elements apiece (21 percent). There are four

activity–elements for wind and three

for visibility. Conspicuously absent are

any activity–elements for tropical

cyclone (i.e., hurricane) information.

None of the airports that participated

were located in coastal regions where

storm surge might be an issue, and

other phenomena associated with

tropical cyclones are accounted for by

the precipitation, wind, thunderstormrelated, or visibility activity–elements.

Nor did any of the participants report a

need for information on weather

elements in the miscellaneous

category. If the survey were repeated

now, homeland defense issues that have grown since September 11, 2001, would very likely lead

to an interest in air transport and dispersion information in the event of release of a nuclear,

chemical, or biological hazard.

4.8.3 Impacts and Mitigation Actions, by Weather Element Group

This section discusses the effects that specific weather elements have on airport ground

operations and the response actions that the WIST study participants identified as potentially

influenced by accurate information on each element. Mitigation actions can range from simply

increasing awareness to taking specific corrective actions or curtailing or suspending activities.

All these actions are intended to avoid unnecessary cost, damage to property, or safety risk to

people. As discussed in Section 4.2, weather impacts can be mitigated or obviated to varying

degrees by timely action, and response decisions are affected by many factors other than weather

information.

Precipitation Elements

With any amount of freezing or frozen precipitation (ice or snow), the sector activities

experience impacts to safety of personnel, impaired operations, and risk to aircraft and

equipment. Heavy liquid precipitation (rain) impairs operations primarily because it reduces

visibility and creates flooding risks to personnel and equipment.

Safety of flight is paramount, and it begins on the

ground. Aircraft icing is a critical condition that

affects safety of flight. Ice on aircraft caused by

freezing or frozen precipitation of any kind, along

Figure 4-11 Airport ground operations activity-elements by 

weather group.

39%

21%

11%

8%

21%

0% 0%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Precipitation

Thunderstorm

Related

Wind

Visibility

Temperature

Related

Tropical

Cyclone, Sea

State, Ice

Miscellaneous

Activity-Element Count

Aircraft icing is a critical condition that affects

safety of flight. Thus, the effective and assured

de-icing of aircraft on the ground before takeoff is essential.
4-51

with frost and rime icing picked up on descent, all affect the aerodynamic performance of

aircraft. Lift is dramatically affected, most often during the critical take-off and landing phases of

flight. Thus, the effective and assured de-icing of aircraft on the ground before take-off is

essential. When conditions conducive to icing are forecast to occur, airport and airline operations

managers are advised of the threat. They plan for the availability and readiness of equipment,

supplies, and manpower. Airport tenants are alerted, and de-icing pads are prepared for use. The

airport continues to issue advisories to tenants on type of precipitation expected, expected

accumulation and duration, temperature, and wind. Airlines may implement personnel recall to

cover the additional function of de-icing airplanes.

The acceptable "hold-over-time"—the time between the beginning of de-icing and take-off—

varies with weather conditions and the type of de-icing fluid used. Based on the forecast and

observation of the type and rate of precipitation, wind speed, and temperature, a fluid is selected

that will be most effective. When feasible, operators begin applying de-icing fluid before

precipitation begins, using an agent that prevents precipitation from bonding (freezing) to the

wing surface. Then, on take-off roll, the accumulated precipitation will slide off the wing. Other

agents can be applied to remove frozen precipitation from aircraft surfaces. Frost and "cold

wing" icing are routinely dealt with, even when freezing precipitation is not present. Efficient

and well-planned de-icing operations can minimize schedule impacts.

Aircraft icing is by no means the only threat from freezing or frozen precipitation. Accumulation

of ice and snow affects all aspects of airport operations. It increases risks to personnel safety and

equipment and causes operational delays and cancellations. It may close runways, limit airport

parking, and generally inhibit all activities that require surface movement about the airfield and

airport grounds. To mitigate these effects, airport operators rely on early planning to ensure

availability and readiness of equipment and supplies (stockpile of salt/sand for roadways and

parking areas and of other materials for runways and taxiways). They plan manpower availability

and implement personnel recall plans (some airlines use a 24–30 hour forecast for a preliminary

staffing estimate); advise carriers, the fixed base operator, and all tenants; and prepare de-icing

pads for use. As an anticipated event occurs, they decide on choice of surface treatments (antiice, sand, etc.); execute snow and ice control plan(s); begin treating runways, taxiways, roads,

parking areas, and walkways; and monitor pavement subsurface and surface temperatures for

continued snow removal strategy. Airlines may begin de-icing aircraft at the gate with activation

of the snow plan; they may also implement schedule changes and plan for reconstitution of

normal operations.

In general, if freezing precipitation is observed to be moderate or greater, and ice is accumulating

on surfaces and structures, airport flight operations will likely cease. Heavy snow coupled with

high winds will cause blizzard conditions and “white outs,” in which case snow removal ceases

until visibility improves.

Intense liquid precipitation (rain) also impairs airport ground operations. It impedes construction

projects, reduces visibility, slows down all vehicular movement on the airfield (both on the ramp

and on access roads and parking areas), impedes foot traffic, and presents a safety risk for

employees and passengers. These direct effects, as well as some of the mitigating responses, can

cause schedule delays. Mitigating actions for heavy rain include issuing advisories to all airlines
4-52

and all other airfield tenants, planning for vehicular traffic flow to bypass known trouble areas,

coordinating with other agencies in the vicinity for opening drainage control points, preparing

equipment for sweeping or pushing standing water, and ensuring that adequate equipment and

trained personnel are available.

Thunderstorm-Related Elements

Thunderstorms and their related phenomena can be very severe, causing loss of life and property,

but they generally affect smaller areas for shorter periods of time than do some other weather

elements. When severe thunderstorms do occur in the immediate vicinity of an airport or are

forecast to move over it, all sector activities respond to the potential risks to people, aircraft, and

other equipment. The range of protective actions is similar, with most activities ceasing outdoor

operations in the vicinity of the threatening weather and personnel required to take shelter as

necessary.

Lightning is the most common thunderstorm-related threat. Most activities begin halting

noncritical activities when lightning is observed at or near the outer boundaries of their lightning

detection grid. When lightning is observed within 3 nautical miles of the airfield, all refueling

operations are halted and personnel are moved inside or under cover. (Some operators reported

that they take their people off the line when lightning is observed at or within 10 nautical miles

of the airfield.)

Hail can damage cargo, equipment, and vehicles, as well as injuring personnel. Hail greater than

1 inch in diameter can severely damage aircraft sitting exposed on the ramp. Hail also affects

aircraft servicing (refueling and maintenance) and causes operational delays and cancellations. It

impedes construction and airfield maintenance projects. Protective actions include curtailing

outside activities where possible and moving personnel inside or under cover.

In almost all cases, the desired lead times for forecasts of thunderstorm-related weather begin

with a “heads up” advisory 12 to 24 hours in advance, followed by a warning 4 to 6 six hours

A passenger maneuvers her

luggage cart through rain at

the Atlanta airport. A

forecast of snow and ice for

this day led Delta Airlines

to cancel many of its

Atlanta flights, causing

delays throughout the

nation. Copyright AP Wide

World Photos.
4-53

before onset. This is followed by a “take cover” type of warning an hour or less from the actual

occurrence of the severe weather, with real-time updates when a storm is actually occurring and

affecting operations.

Temperature-Related Elements

Temperature-related activity–elements, specifically air temperatures less than zero °F and wind

chill temperatures below -20 °F, account for 21 percent of the total for this sector. These cold

temperatures primarily affect personnel working outside, including aircraft maintenance,

refueling and servicing, baggage and cargo handling, and construction projects. The primary

risks are hypothermia and frost bite for personnel and, to a lesser extent, risks from water

freezing on aircraft as they are being serviced. In addition, cold temperatures can result in delays

because ground crew personnel are limited in the amount of time they can work outdoors under

these harsh conditions.

To mitigate the effects of cold weather, personnel are equipped with proper cold weather

protective clothing, exposure time outdoors is limited to periods of 12–15 minutes, ground crews

are provided with warm fluids to help them warm up and avoid dehydration, and extra personnel

are scheduled as necessary. Outdoor construction and maintenance projects are rescheduled or

adjusted as necessary.

Winds

Sustained high winds primarily affect aircraft movement, aircraft servicing and maintenance, and

construction projects. Short-lived wind events, such as microbursts and gust fronts can also

affect airport ground operations, primarily through their effects on takeoffs, approaches, and

landings. Large changes in wind speed or direction affect the choice of runways, and the need to

change runways in use at busy times contributes to schedule delays. Likewise, maintenance on

large aircraft, especially work on areas high above the ground, is impeded or prevented

altogether. Servicing of aircraft is slowed, and more wind-blown foreign objects are present in

aircraft movement areas. All of these impacts contribute to delays in aircraft departures. Snow

removal and de-icing operations are also affected, as snow blower and aircraft de-icing

operations must respond to wind direction and speed. Construction materials are more prone to

blow away in high winds, and blowing dust from construction sites can become a hazard.

Mitigating actions include advising air traffic control and all airfield tenants and planning for

more frequent ramp, taxiway, and runway inspections (to reduce or eliminate damage from

wind-blown foreign objects). Operators will ensure that motorized carts not in use are braked and

chocked for the duration of high winds. Equipment or objects not in immediate use or being

handled (e.g., igloo containers, baggage) are stored in protected areas. If de-icing of aircraft or

snow removal operations are required, operators will decide where and how these activities will

be conducted to control blowing spray and snow. Construction contractors and maintenance

personnel are advised of impending high winds, and they may adjust their work and project

schedules.
4-54

Visibility

Visibility of less than a quarter-mile affects aircraft ground movement, flight operations, vehicle

movement (including aircraft servicing and maintenance vehicles), and construction projects. It

increases the probability of runway incursion incidents. Because all aircraft and vehicular

movement is slowed, reduced visibility can delay schedules significantly. Construction and

repair projects may also be delayed.

Mitigating actions include coordinating with air traffic control and ensuring that "follow me"

guidance vehicles are available for aircraft on request. At some airports, when the runway visual

range drops to 600 feet, no take-offs or landings are allowed. If necessary, airport operations will

also coordinate with construction contractors on project schedules.

4.9 Overarching Themes from the WIST Needs Identification and

Validation Activity

This section highlights four themes that emerged from the WIST needs analysis in this chapter

and from participants’ comments during the two WIST symposia, other meetings, and interviews

conducted during the study.

Theme 1. The WIST study provides a validated baseline of user needs for

moving forward with a coordinated WIST initiative.

Representatives from user communities throughout six surface transportation sectors participated

in the WIST study. These participants, representing federal, state, and local governmental

agencies and commercial interests in each sector, provided the initial responses compiled in the

WIST needs templates and validated the templates. The templates thus provide a validated

baseline of user-defined weather information needs for these six surface transportation sectors.

An American Airlines jet at

LaGuardia airport in New York is

delayed in thick fog. Visibility of

less than one-quarter mile restricts

airport ground operations.

Copyright AP Wide World Photos.
4-55

Users’ needs for weather information, identified and coordinated through the WIST study

process described in Chapter 3, are compiled in Appendix B of this report. The templates have

been reviewed and validated by the federal, state, and local government agencies with oversight

and operational missions in these transportation sectors, as well as by representatives of

commercial firms operating in the sectors. This coordination process revealed an unequivocal

need among the various user communities for weather information that is more accurate, timely,

and relevant.

Theme 2. The benefits from improving WIST data sources, infrastructure,

and applications will be substantial.

The nation can benefit significantly from improved

weather information for surface transportation. The

safety benefits will include reductions in injuries and

loss of life. The economic benefits will include

reduced economic losses and increased productivity.

The challenge is to gather the necessary data, turn it

into relevant and accurate weather information, and

put it into the hands of people who must make decisions about various activities.

Reduction in Injuries and Loss of Life

As noted in Chapter 1, precise numbers for injuries and deaths attributable directly or indirectly

to weather conditions and their impacts on surface transportation systems are difficult to

establish, even for the nation’s highway system. The WIST Needs Templates support abundant

anecdotal evidence that snow, rain, ice, fog, freezing or rapidly changing temperatures, and

numerous other weather elements, as defined in Table 2-1, increase the safety risks to personnel

and travelers in all of the surface transportation sectors. Table 4-8 shows that users identified

risks to safety as an impact of more than three-fourths of the activity–element combinations in

every sector.

Table 4-8 Activity–Elements with Safety Impacts, by Sector

Activity-Elements with Safety Impact

Transportation Sector

Activity–Element

Count

Percent of All Sector

Activity–Elements

Roadway 223 87%

Long-Haul Rail 98 76%

MTS operations 156 83%

Pipelines 98 77%

Transit 110 78%

Airport ground operations. 33 87%

Reliable information on surface transportation elements—what conditions are now or are

forecast to be—allows transportation system managers and operators, as well as travelers, to

make choices that reduce these safety risks. A study, cited in Chapter 1, of one stretch of Idaho

highway reported an 83 percent decrease in accidents after forecast-activated pavement antiicing was implemented (Breene 2001). Surveys of travelers’ attitudes, such as those conducted

The challenge is to gather the necessary data,

turn it into relevant and accurate weather

information, and put it into the hands of

people who must make decisions about

various activities.
4-56

for the ATWIS in the Midwest (Owens 2000) or the Gallup survey of information desired for

“511” travel advisory service (ITSA 2002b), show that travelers value reliable surface

transportation weather information. Finally, the “Actions” listed in the WIST Needs Templates

for weather elements with a safety impact show that transportation decision makers in every

sector have a range of options available to them to lessen safety risks—provided they get

accurate information with the lead time needed to inform their decision processes.

Reduced Economic Losses

NHTSA has estimated that the economic costs just

from weather-related crashes on U.S. highways

amounts to nearly $42 billion annually (Lombardo

2000). Fog, snow, and icy conditions on highway

capacity caused an estimated 544 million vehiclehours of delay on the nation’s freeways and principal

highway arteries in a single year (Chin et al. 2002). Snow and ice treatment costs state and local

highway maintenance departments about $2.1 billion annually (FHWA 1998). Chapter 1 cited

examples of how the intermodal system for freight and cargo that links surface transportation

sectors can be impacted by weather conditions, with ripple effects across the economy, as well as

across transportation sectors. The “Actions” entries in the WIST Needs Templates detail

mitigating actions that can be taken in every sector activity to lessen the economic impacts of a

weather event or weather-related condition.

However, the importance of accurate, timely information, at the needed spatial and temporal

scales, becomes critical in ensuring that the net value of preparing for and responding to an

adverse weather event or condition is an economic benefit rather than a loss. Most of the actions

listed in the templates have an economic cost associated with them. If the weather information

received is timely and accurate, the cost of acting is often less than the cost of failing to act. If a

predicted event does not occur, however, the cost of the unnecessary preemptive action remains.

Users’ perceptions of the reliability of the transportation weather information they receive

determine how much they rely on that information in making difficult economic choices.

Forecasts that correctly predict that an adverse event or condition will not occur are also of

economic value. As an example, for a local government a single correct weather forecast that

prevents the unnecessary deployment of snow and ice crews can mean the difference between

operating within budget and becoming seriously overextended, requiring the cancellation or

deferment of other critical highway maintenance projects.

Increase in Productivity

Weather affects the efficiency and effectiveness of each of the major modes of surface

transportation. A good example is the freight community, with its concept of multimodal just-intime delivery. In moving goods across the country, freight companies must plan for, or cope

with, weather of all types and severity. The efficiency of the system depends on a high level of

coordination among producers and shippers. All the transportation modes used in the supply

chain rely on weather information to sustain this tight coordination. To the extent that disruptive

weather conditions can be anticipated and communicated, mitigating actions can be taken to

The “Actions” entries in the WIST

Templates detail mitigating actions that can

be taken in every transportation sector to

lessen the economic impacts of weather

events or weather-related conditions.
4-57

maintain the overall coordination of a just-in-time delivery system. Throughout the economy, as

well as within transportation systems, efficiency and effectiveness can be improved.

Across all the sectors studied, two lead-time periods for weather information to be useful to

surface transportation activities stand out. There is a planning window at 12–24 hours and a

response-implementation window at 0–3 hours (extending to 6 hours in some sectors).

Theme 3. Substantial near-term benefits can be reaped just by increasing the

utility of currently available data and products to WIST users.

Many of the weather information needs specified in the WIST templates (and discussed at the

general level of activity–elements in this chapter) can be met to some degree today, simply by

distributing existing weather data and products more quickly and widely through open systems.

The utility to WIST users of available weather-related data and information products can be

increased in the near term simply by:

• Making more information more accessible to more users through open information

systems

• Tailoring the format and content of information products to be readily understood by

potential users and easily incorporated into their decision procedures or decision support

systems.

The ability of a WIST user to incorporate weather

information into decisions often depends on how

quickly and easily the information can be

assimilated into that user’s planning window or

operational decision time frame. There are roles for

both the public and private sectors in meeting these

needs. The disparities among various users with

respect to their knowledge of the sources and

availability of weather information present

opportunities for commercial providers. They can

meet many of the validated WIST needs by tailoring generic data and products from the public

sector, then delivering the results with existing and emerging information technologies. Some of

the many issues involved in expanding this public–private partnership in meeting WIST needs

will be addressed in Chapter 5, as part of suggested next steps for a coordinated WIST initiative.

Theme 4. Over the next decade, additional and substantial benefits to the

nation, in terms of safety, reduced economic losses, and increased

productivity, are possible with (1) better spatial and temporal resolution in

both forecasts and observations and (2) better forecast accuracy.

Almost all participants in the WIST needs validation stressed the critical importance of accurate

weather information. Across sector activities, weather elements, and thresholds, increased

accuracy is essential for meeting user needs. Most WIST users desire weather information that is

more precisely specified in terms of spatial and temporal resolution than what is now available.

“The mechanism for providing the (weather)

information is not nearly as important as the

accuracy of the information.... For K-12

education systems such as Fairfax County Public

Schools, the specific timing of weather events is

critical to effective decision making.”

 Dean Tistadt, Assistant Superintendent,

Fairfax County Public Schools, Virginia
4-58

They want weather information that matches the geographic and temporal scales of the sector

activity they conduct and the mitigation actions they have available for responding to threatening

weather. These needs include weather information that is valid both at the current time and at

some specified time in the future.

As accuracy and consistency increase, user confidence in weather information products

increases, which leads to increased reliance upon it in the users’ decision-making processes.

Thus, improved accuracy is a requirement for improving the safety, efficiency, and effectiveness

in surface transportation systems by making more use of weather information.

Uncertainty and risk in weather predictions need to be addressed by both the research and

operations communities. Probabilistic forecast products may help to convey the full range of

uncertainty present in a prediction. However, either the user needs to be skilled in interpreting

probabilistic information or a decision support tool is needed that interprets the probability

information in terms the user can comprehend and use.

4.10 Summary: Meeting the Needs and Addressing the Concerns of WIST

User Communities

The WIST needs collection and validation effort provides ample evidence that the nation can

benefit greatly by improving the weather information provided to the activities responsible for

surface transportation systems and services. The benefits will accrue not only to the traveling

public but also to the various levels of government and to the commercial enterprises that rely on

transportation to accomplish their missions or to satisfy their customers’ demands.

Many of these benefits could be achieved now, by improving the delivery of currently available

weather data and forecast products through open systems and integrating them into formats and

information products tailored to the needs of decision support processes throughout the spectrum

of surface transportation activities. These near-term results will substantially improve the value

of WIST to surface transportation in all sectors. Beyond this near-term “low-hanging fruit,”

additional benefits will require observations and forecasts at higher spatial and temporal

resolution than the current state of practice. It will also require improved forecast accuracy

across the range of spatial and temporal scales needed by WIST users.

Some progress has been made in improving weather information for surface transportation

decision makers. Still, this WIST study process gathered many concerns from participants who

are either WIST users themselves or are well acquainted with users’ needs. The deficiencies and

gaps identified through this process require attention if WIST users’ needs are to be met. Chapter

5 suggests next steps toward addressing these concerns.
5-1 

Chapter 5

WIST Strategic Thrust Areas

5.0 Introduction

This chapter defines six strategic thrust areas for next steps in addressing validated user needs for

weather information for surface transportation (WIST):

1. Identifying and specifying the gaps in coverage of WIST user needs

2. Expanding coordination among research and development (R&D) programs and

providers of WIST products and services

3. Clarifying and defining roles and responsibilities in the information provider and

disseminator communities that acquire, interpret, and tailor WIST to meet user needs.

4. Translating research results and new technologies into WIST applications

5. Supporting research to expand and fill gaps in the fundamental knowledge that enables

and supports future technology development and application

6. Expanding outreach and education to both current and potential WIST users.

The purpose of this chapter is to characterize each of these strategic thrust areas well enough to

specify one or more broad goals in each area, plus suggested next steps toward these goals. To

this end, the discussion addresses courses of action to overcome barriers and meet the challenges

in each strategic thrust area. The chapter closes with a vision of how future surface transportation

systems in the United States could be improved by a concerted effort to meet the user needs

documented by the WIST needs study.

5.1 Strategic Thrust Area 1: Identifying and Specifying the Gaps in

Coverage of WIST User Needs

This report culminates the initial phase of needs identification and verification in a coordinated

effort to understand and address WIST user needs. The needs compiled in the WIST templates

include many that can be met with data already available to users, plus others that could be met

with information derivable from available data. For the remainder, however, the data generally

available are not at the levels of reliability, timeliness, or spatial and temporal specificity

required for WIST users in making operational decisions. An important thrust area for continuing

the WIST effort is to conduct a detailed analysis of the gaps in coverage, the nature of the gap

(why is current data not adequate?), and how a diverse provider community of both public and

private sector providers can best cover these gaps.

5.1.1 Barriers and Challenges in Identifying Unmet WIST User Needs

Meteorological support and services from the public sector have traditionally focused on the

needs of the general public (for information to protect life and property) and on aviation weather
5-2 

support. Weather information providers have not met the needs of the surface transportation

communities for accurate information at high spatial and temporal resolutions. This information

also must be provided with sufficient lead-time (for forecasts) or currency (for observations) to

guide operational decisions. With the rapid increase of applications for weather information in

surface transportation activities and the increasing importance of WIST, information providers in

both the public and private sectors need to pay more attention, in the form of resource investment

and priority, to WIST users’ needs. As noted in Section 1.3.3, specialized weather information

services and products evolved over time, and sometimes belatedly, to meet the needs of diverse

users within the aviation community. Thus, the history of aviation weather provides a

precedent—with both positive and negative lessons—from which the WIST provider community

can learn.

From the perspective of WIST users, limitations in the available weather data and forecasts have

restricted their utility for surface transportation operations, even though the right kinds of

information, if received with adequate lead time, could improve many types of surface

transportation decisions. As noted in Chapter 4, many of the WIST needs identified by this study

require very high resolution weather information to meet the need fully. This information is not

generally available, from either observations or predictions based on numerical modeling, with

the reliability and access times needed to influence decisions. There are also a large number of

nontraditional or sector-unique weather (and environmental) elements that are important to

WIST user communities.

Private-sector participants in providing (including producing, adding value to, or disseminating)

WIST services and products will set their own criteria for defining their potential roles and

responsibilities. However, a mechanism is needed to coordinate federal roles and responsibilities

that cut across the transportation information infrastructure. For example, if a roadway weather

capability for highway users is being developed or demonstrated operationally, some mechanism

Railroad cars are stranded on a

stretch of flooded track after

Tropical Storm Alberto doubled

back over the area. Good advance

warning as Alberto came off the

Gulf of Mexico in July 1994 led to

very little damage. The lack of

warning when the storm came back

caused considerable damage to rail

operations.
5-3 

is needed to recognize and push for the opportunities to leverage the technology in other sectors,

such as the U.S. Marine Transportation System (MTS) or railways.

Participants in the WIST user meetings conducted for this survey supported a proposal to

establish a nationwide baseline of weather information needs for surface transportation and

endorsed the pursuit of solutions that would meet these needs. This report provides a first attempt

at such a baseline of WIST needs. Next, a joint effort is needed to determine which needs are not

fully met and how these gaps should be addressed. Finally, this initial baseline of WIST needs

will require extension to other sectors and activities, as well as continued monitoring, advocacy,

and validation, to ensure it continues to comprehend and represent the needs of surface

transportation communities.

5.1.2 Next Steps for Strategic Thrust Area 1

Goal for Identifying Gaps in Coverage of WIST Needs. Identify validated user needs for

surface transportation weather information that cannot be met with existing information

resources of the public–private provider community. Determine whether technology

development in progress will meet the need or if additional technical development and/or

research is needed.

Next Step 1A. The federal partners in the WIST effort should charter an appropriate entity

(e.g., a task force or program council) to:

• Ascertain (1) which WIST user needs in the initial baseline compilation are fully met

now, (2) which could be met more fully through improved presentation and

interpretation of current observational and forecast data, and (3) which require data

that are not yet available or that have attributes (e.g., accuracy, spatial and temporal

scale, timeliness) beyond what is now available

• Review and sustain or adjust priorities for research programs and for transitioning

promising tools and other technologies into operations

• Support agency processes to validate and update user needs and provider community

programs and approaches for addressing them.

Next Step 1B. Sustain and expand the dialogue between the meteorological community as

information providers and surface transportation communities as information users.

Next Step 1C. Use the baseline of WIST needs represented by the templates developed

during this study as a work in progress, to be refined, extended, updated, and validated by

the participants in a continuing assessment of where capabilities can be delivered that fill

an identified gap or enhance value.
5-4 

5.2 Strategic Thrust Area 2: Expanding Coordination Among WIST R&D

Programs and WIST Providers

5.2.1 Barriers and Challenges to Expanded Coordination of WIST Efforts

Funds for improvements in weather information for surface transportation systems do not enjoy a

high priority in state or federal agencies. As a result, programs and projects to increase the

application of science and technology innovations are sponsored and funded haphazardly across

the nation. This uncoordinated approach leads to duplication of effort and to lost opportunities

for leveraging programs that could be applied in other states or nationwide. To accelerate the

application and use of new or emerging technologies and capabilities for WIST support,

technology transfer processes (concepts, capabilities, practices, and tools) linking the

government and private sectors need to be enhanced.

Work to be done in this area includes more, and better, coordination and agreement among

federal, state, and local governments and the private sector on the provision of data and services.

The National Oceanic and Atmospheric Administration (NOAA) and commercial value-added

vendors of weather information have been making progress on this “division of labor” in

disseminating general meteorological information. Successful examples of coordination and

active partnering can also be seen in the maturation of R&D projects that began under the Road

Weather Management Program of the Federal Highway Administration (FHWA) and are now

moving toward commercial operation (see Section 1.3.1). The FHWA and the Intelligent

Transportation Society of America (ITSA) have worked out many areas of coordination and

partnering for technology transfer related to intelligent highway systems, as represented in the

National Intelligent Transportation Systems Program Plan: A Ten-Year Vision (ITSA 2002a).

The Transportation Research Board of the National Academies has long served as an important

coordinating and technology transfer agent for federal, state, academic, and private-sector

entities concerned with transportation-related research and technology. However, the

opportunities to meet weather-related information needs of surface transportation decision

makers, made possible by the advances in science and technology described in Chapter 1, open

up new domains for coordination and partnering.

The guiding principle for expanded coordination and partnering must be to transfer the results of

R&D programs, typically funded with federal support, to whichever entities are most capable of

implementing effective and efficient delivery of WIST services and products to the users.

• Partnering is needed to guide and support the R&D agenda and to secure and maintain

advocacy and funding for infusing technology (through technology transfer and

implementation) into operations. New relationships among public and private sector

groups will require changes in how federal agencies support, coordinate, and participate

in the rapidly expanding WIST provider community.

• These evolving relationships may require changes in the roles and responsibilities of the

federal partners in the Federal Committee for Meteorological Services and Supporting

Research (FCMSSR), both as sponsors of R&D and as partners in WIST technology

transfer and information dissemination.
5-5 

• Designation of the Federal Aviation Administration as lead agency was critical for

progress in coordinating the federal effort on aviation weather (see Section 1.3.3).

Similarly, designation of a lead agency for WIST may be critical for coordinating WIST

programs and related activities. As Figure 5-1 indicates, a number of Department of

Transportation administrations, as well as other departments and agencies, have

significant responsibilities and interests in surface transportation sectors.

5.2.2 Next Steps for Strategic Thrust Area 2

Goal for Coordinating R&D and Technology Transfer. Expand and improve the coordination

and communication among both WIST-relevant R&D programs and field implementation

programs and projects aimed at incorporating WIST elements in the decision processes and

decision support systems used by transportation activities in all sectors. New and expanded

partnerships among government entities, the private sector, the academic R&D community, and

public-private entities for provision of WIST services and products should aim at increasing the

efficiency and effectiveness of translating R&D results into operational value for WIST users.

Next Step 2A. Coordinate the WIST-related R&D research efforts and technology transfer

programs of federal agencies, including but not limited to the U.S. Weather Research

Figure 5-1 WIST users in each of the transportation sectors.
5-6 

Program, the national Intelligent Transportation Systems research efforts, and a WIST

R&D Program as proposed in Section 5.4 of this report. Transfer of research results and

technology demonstrations to operational capabilities, services, and products available

to WIST users should be a major component of this expanded coordination effort.

Next Step 2B. Prepare for and form strategic partnerships and alliances among government

entities (federal, state, and regional/local), the private sector, the academic R&D

community, and public-private entities.

Next Step 2C. To provide the legislative basis and funding support for expanded

coordination, the provider communities, with the support of the WIST user communities,

should give immediate attention to:

• Reauthorization of the U.S. Department of Transportation surface transportation

program under the Transportation Equity Act for the 21st Century (TEA-21)

• Full support for the MTS as proposed by the Marine Transportation System National

Advisory Council and the Interagency Committee for the Marine Transportation

System.

5.3 Strategic Thrust Area 3: Clarifying and Defining Provider Roles and

Responsibilities

5.3.1 Barriers and Challenges to Clearly Defined Roles and Responsibilities

In all of the surface transportation sectors, information and communication linkages between

transportation system users and providers are proliferating. The challenge is to use these new

capabilities to maximize management and efficiency in the nation’s surface transportation

systems. WIST products and services are one piece—but an important piece—of this infusion of

information and communications technologies into surface transportation systems.

A significant barrier to improving the products and services available to WIST users is that the

roles of federal entities versus those of state and local governments or the private sector are

neither clear nor consistent. Fuzzy boundaries in the roles and responsibilities of the public and

private sectors in generating, tailoring, and communicating WIST to users have at times fostered

strained and even adversarial relationships between these sectors. For example, some

commercial weather services have disagreed about the type or amount of products or services

that should be provided to the public by NOAA’s National Weather Service (NWS). The

disagreements reflect differences between broad and narrow interpretations of NWS

responsibilities.

Continued cooperative efforts by all parties in the WIST provider community will be necessary

to resolve these conflicts and gaps in the service, guidance, and regulatory structures that

influence delivery of weather information to WIST user communities. Explicit policy guidance

on the roles and responsibilities of public and private sector participants in providing and

tailoring weather information would provide a solid basis for expediting provision of new and

improved products and services to WIST user communities.
5-7 

The two subsections below describe avenues through which provider roles and responsibilities

can be clarified:

• Supporting data standards and a national data collection system

• Pursuing an open systems approach in WIST information systems.

5.3.2 Next Steps for Data Standards and a National Data Collection System

Surface transportation operations require timely and reliable data. However, the means of

generating, obtaining, transferring, and applying weather information are not standardized at

present. This lack of standards significantly hinders dissemination and application. Nonstandard

or erratic updates to observations and forecasts undermine the value of weather information for

transportation-related decision processes and systems. Restrictions on the radio frequency

spectrum complicate the choice and availability of the communication system used to report and

distribute data.

The WIST user communities to be supported with timely data are numerous and diverse. This

diversity presents a special challenge for standardization efforts. Nearly every user has unique

aspects of its operation, so any specific solution is unlikely to be broadly applicable across all the

WIST user communities. Some users are seeking and obtaining high-resolution weather

observations from nontraditional sources, but data standardization and quality control issues may

encumber wider dissemination and broader application.

Mesonets have been implemented in several states to support state and federal programs, as well

as academic research and private sector applications. Issues associated with increasing the value

of such networks include standardizing sensor technology and calibration methods, siting the

sensors, collecting and processing the data (whether it is proprietary or public), access to the

data, and integration of mesonet data with data from federal systems. Through the

Meteorological Assimilation Data Ingest System (MADIS) program, the FHWA has been

working with the NOAA Forecast Systems Laboratory to highlight the benefits of making

observations from roadway weather information systems, operated by state departments of

transportation, available to other surface transportation and meteorological communities.

MADIS access to mesonets provides for data acquisition and data quality control. In selected

cases, the information is made available to users for further processing. To date, 10 states have

agreed to participate in MADIS. The Cooperative Observer Network, operated by the NWS, is a

nationwide weather and climate observing network that, when modernized, will provide a useful

framework for more extensive national collection and integration of weather and environmental

data from regional mesonets.

Goal for Data Standards. Provide guidance on the roles and responsibilities of the public and

private sectors for various types of observations and networks, particularly in light of better

understanding of the accuracy needed to support the nontraditional weather/environmental

elements and the new higher-resolution observation and modeling products required by WIST

users.
5-8 

A nationwide collection of local weather data does not exist and has not been mandated. These

data are usually of greatest value locally, but ideally they should then be passed to a national

collection location, where the data can be subjected to quality controls, aggregated, synthesized,

and archived. Lack of advocacy by the states and other users has hampered funding and

development of a national collection process. Other factors inhibiting a national collection

process include commercial profit requirements of the private sector and the sometimes

adversarial relationship between the public and private sectors with respect to roles and

responsibilities.

Goal for Nationwide Data Collection. Integrate proliferating surface weather observations and

networks and incorporate their data, along with data from the Cooperative Observer Network,

into a nationwide data system. This data system should provide access to related geophysical

data of value to surface transportation operations. This effort should address:

• Equipment (measurement/sensor adequacy and accuracy, siting criteria, calibration, metadata, and legacy systems)

• Communications protocols and standards

• Data standards for quality control, accessibility, compatibility, interoperability,

and archiving.

The NOAA/NWS Cooperative Observer Network spans the nation. Each dot represents an observing

location. Source: National Climatic Data Center.
5-9 

Next Step 3A. Determine the roles of NOAA/NWS and/or other public and private sector

partners in pursuing the above Goal for Nationwide Data Collection.

Next Step 3B. Address issues of observation standards and protocols, equipment siting, data

collection, processing, archiving, access, and proprietary data through the use of a task

force or similar action group.

Next Step 3C. Examine, test, and implement operationally current and emerging technologies for system definition and transition, system optimization, modal optimization, and

environmental considerations.

5.3.3 Next Steps for an Open Systems Approach for WIST

For an information network with many providers of services and products, serving a diverse

community of consumers, there are technical advantages to open systems architectures for

communications and interfaces. Decision support tools should be implemented as an application

layer on top of this open-systems foundation. Education of users and providers about these

advantages is critical to efficient delivery of WIST services and products that are tailored to the

needs of surface transportation decision makers and their decision support systems.

The national Intelligent Transportation System (ITS) architecture and other elements of the ITS

initiative can provide a framework and starting point for deciding on technical issues of data

management and accessibility (e.g., format standards) for WIST communications in all surface

transportation sectors. These elements of technical infrastructure can also aid in resolving the

more difficult issues of the boundary between public information and commercial or proprietary

tools for presenting and interpreting information to support users with special needs and

interests. There must also be attention to security issues, including protecting the integrity of

shared data resources and managing the risk that open information will be used in hostile actions.

Goal for Open Systems in WIST Communications. Resolve the technical aspects of providing

open access to weather information in a manner that benefits diverse WIST users fairly, while

providing commercial or mixed public-private value-added suppliers with a level playing field

and reasonable incentives for participating. Address issues of data system security.

Next Step 3D. Work toward full compatibility of transportation-related communications

and information systems with the national Intelligent Transportation system

Architecture.

Next Step 3E. Establish a task force to develop a security strategy for national weather

information networks, addressing issues of data integrity and the balance between

open access to data and restrictions to avoid hostile use of data systems and resources.
5-10 

5.4 Strategic Thrust Area 4: Translating Research Results and New

Technologies into WIST Applications

A number of currently unmet WIST user needs can be met in the near term (within 5 years)

through applied research or development of technology applications. Some of these technologies

incorporate advances in observing or forecasting meteorological parameters; others involve

weather-affected conditions such as black ice on highways or railbed ground heave. Still others

involve information technology and software to make WIST data easier to incorporate and apply

in users’ decision processes. For these areas, translating research results and science into

practical information for users is the near-term objective.

User needs that will require more fundamental research—such as major advances in misoscale

forecast models—are likely to require longer time horizons. These needs are addressed by

Strategic Thrust Area 5.

5.4.1 Highlights of Applied Research and New Technology with Near-Term

Payoffs for WIST Users

Appendix E provides a detailed list of research topics and technology development relevant to

WIST user needs. The following bullets highlight some of the areas in which significant results

for WIST users appear feasible within the next 5 years:

• Integration into operational transportation information systems of newly developed

technologies for observing and predicting fine-scale weather-related hazards such as:

 Temperature-dependent effects on infrastructure that are difficult for operators to

identify with unaided visual information, such as black ice on roadways or railbed

frost heave

 Sun glint and glare

• Better forecasts of MTS weather and environmental conditions by improving and

expanding oceanographic sensor systems and improving models that incorporate weather

data with water levels, tides, and currents

Vehicles pass through a flooded

underpass in Chicago on August

22, 2002, after 5-8 inches of rain

fell. Copyright AP Wide World

Photos.
5-11 

• Weather elements and related conditions that can be observed with existing technology as

point measurements but require accurate fine-scale spatial distribution modeling for

surface transportation applications such as:

 Frost heave of road surfaces and railways

 Spatial distribution of pavement or rail/railbed conditions (temperature, frost, ice,

etc.) between the point measurements available with roadway or railway monitoring

sites

 Spatial variability in rainfall and rainfall rates, leading to hydroplaning and other

localized flooding hazards along transportation routes

 Hydrologic implications of rainfall for surface transportation infrastructure and

systems (all transportation sectors)

 Spatial distribution of blowing or drifting snow and its impact on transportation route

visibility (roadways, railways, waterways)

 Dissipation of anti-icing chemicals

• Information technology for access to and applications of WIST, including WIST inputs to

intelligent transportation systems and the MTS, such as:

 Refined in-vehicle and in-vessel displays for WIST and for decision support tools that

incorporate WIST information in their graphical output

 Filtering and fusion processes to tailor meteorological, environmental, and route

condition data and information for decision support systems and user procedures

specific to surface transportation applications

 Advanced communication technologies (e.g., wireless, automatic voice response) and

graphical products applied to decision support systems, particularly those for mobile

and remote nodes of intelligent transportation systems

 Development and distribution of tools and guidance to assist decision makers when

contaminants or hazardous materials in transit are released to the ground, the

atmosphere, or surface waters

• Improved sensing and measurement technologies and collection/processing of

observation data, including:

Road weather information can be integrated

into “intelligent dashboard” information

systems for highway travelers. Courtesy

OnStar Corp. Copyright 2002, all rights reserved.
5-12 

 Metadata standards for all observational systems

 Definition of roles for remote sensing technologies in planning for sensor systems and

in complementing, supplanting, and expanding in situ sensing

 Standardized methodologies for collecting, processing, and archiving observation

data.

There are many more research requirements listed in Appendix E for which some near-term

results with operational value are likely, but longer-term R&D effort will probably be needed to

meet WIST user needs completely. These requirements are indicated as both near-term and farterm in Appendix E.

5.4.2 Challenges to Current Technological Capabilities and Understanding

Uncertainty and risk in predictive information pose challenges for both weather research and

information technology developers. Uncertainty in predictions of environmental conditions

depends in part on the quality and density of observations on which predictions are based. The

uncertainty usually increases as the predictive time horizon increases. Many operational

decisions for transportation systems and activities require lead times of 12 to 24 hours. Although

current mesoscale (grid points separated by 10 km or less) weather models provide forecasts out

to 48 hours, the spatial and temporal accuracy of the forecasts is not high enough to meet the

reliability needs of many transportation decision makers. Forecasts at longer times are available

only at synoptic-scale resolutions, which are much less useful for many transportation decisions

and still do not provide the reliability (forecast skill) WIST users need.

Decision support systems will need to incorporate techniques for working with the predictive

uncertainty inherent in high-resolution forecasting at longer lead times. For example, various

predictive sources can be weighted according to their reliability, and risks can be represented in

ways that are useful for decision making (Nelson 2001, p. 6).

For a number of activities in the surface transportation sectors, an accurate forecast of favorable

weather is often just as important as a forecast of adverse or mission-limiting weather. For

understandable reasons, most meteorological research and technology development have focused

on understanding the precursors for adverse weather, to aid in predicting it more reliably. In

many respects, the basis already exists in observational data and model predictions for more

detailed predictive information on favorable weather, including measures of uncertainty in

forecasts of fair weather.

A major challenge in translating advances in meteorological and related science into practical

and useful information is to present the information in terms that users understand and can

incorporate effectively in their planning and operational decisions. Advanced decision support

systems will be increasingly important in translating observations and forecast data into useful

inputs to decision processes. However, more professionals will be needed who have training in

meteorology and related science fields but also understand and can communicate in the

perspective of the users. These “WIST communicators” are an essential complement to the

software tools. They will play a major role in developing better tools, applying them to specific

users’ needs, and continuing to improve them.
5-13 

A multi-faceted WIST research and

development program, coordinated with

the U.S. Weather Research Program, is

needed to address validated user needs.

5.4.3 Opportunities in Current and Emerging Technologies

Opportunities in Weather-Related Research and Technology Development

As the principal source of meteorological observations and forecasts for the nation, the NWS

benefits from continuing improvements to its NEXRAD radar system, Advanced Surface

Observing System (ASOS), weather satellites, and AWIPS—the information processing and

networking system that ties all these observation platforms to the national forecast centers and

local forecast offices. The broad range of users of NWS data and products—including end users,

communications media, and providers of value-added meteorological services—benefit from this

new technology as it improves NWS capabilities.

The U.S. Weather Research Program plays a key role in providing the fundamental knowledge

and application development that feed this ongoing and vital stream of new meteorological

technology (see text box next page). This program has substantial value as an umbrella program

through which all federal entities with weather-relevant program objectives contribute resources

to a coordinated R&D effort. Increased support for areas in which the U.S. Weather Research

Program is clearly addressing WIST needs is an efficient and effective option for coordinating

the federal R&D effort.

However, the limited portfolio of the U.S. Weather

Research Program, together with its emphasis on

research rather than operational implementation,

constrains its capability to serve all the WIST R&D

needs of federal agencies. The range of R&D required,

and particularly the specificity of applications tailored to the needs of the surface transportation

communities, argues for a separate WIST Research and Development program. This program

would address issues relevant to weather impacts on surface transportation (all sectors) and to

improving the capability to move meteorological and other weather-related information into

users’ decision processes. A major focus should be near-term and longer-term technology

development and transfer, and the related applied research, to address validated WIST user

needs.

An important objective for a WIST R&D program would be to exploit relevant scientific and

technical capabilities across the country. These capabilities can be tapped through partnerships

This weather satellite in geosynchronous Earth orbit

uses advanced technology to provide weather and

environmental information to the National Weather

Service and many other users. Courtesy NOAA Photo

Library
5-14 

with the private sector and mixed public-private service providers, where appropriate, as well as

through university-based R&D consistent with the program’s portfolio. Finally the two multiagency programs—a new WIST R&D program and the existing U.S. Weather Research

Program—should be fully coordinated to ensure that federal R&D investments are made wisely

and productively.

In addition to the U.S. Weather Research Program, R&D programs under a number of federal

departments and agencies provide technology for various surface transportation communities.

(See Appendix F for a detailed description of these federal R&D activities.)

• The FHWA has major R&D initiatives in Intelligent Transportation Systems, Road

Weather Information Systems, and decision support systems that exploit WIST and

related information about roadway conditions.

• NOAA’s National Ocean Service has programs to improve the observation systems and

modeling capability for water levels, currents, and under-keel clearances in the MTS.

Greater coordination of the R&D effort across these and other intramural programs, as discussed

in Section 5.2, in conjunction with an interagency WIST R&D program, would leverage the

federal investment in improving and expanding WIST.

U.S. Weather Research Program

The U.S. Weather Research Program is a partnership of federal entities—currently NOAA, the National

Aeronautics and Space Administration, the National Science Foundation, and the Navy participate—with the

academic and commercial communities. The program’s overarching goal is to accelerate improvement in highimpact weather forecasting capability—in particular improvement in forecast timing, location, and specific

rainfall amounts associated with hurricane landfall and flood events that significantly affect the lives and

properties of U.S. inhabitants (USWRP 2001, p3.).

Portfolio development for the program begins with a prospectus development team of experts, which identifies

research needs and opportunities related to a topic of importance to the program goal. The second step is to

develop an implementation plan for the research identified by this team. Just two of the program’s highest

priorities, hurricanes at landfall and quantitative precipitation forecasting (QPF), have reached this second stage.

Research projects to address the hurricanes at landfall implementation plan are underway, but funding

constraints have limited implementation of the QPF research plan.

In August 1998, a new prospectus development team met to “identify and delineate critical issues related to the

short-term prediction of weather in urban forecast zones” (Dabberdt et al. 2000). Funding limitations have kept

the recommendations of this and other prospectus development teams from moving to the implementation plan

stage, after which actual research would be funded. Even within this limited portfolio, the U.S. Weather

Research Program is pursuing some of the research required to meet some WIST user needs validated in this

study. If the prospectus development team’s priorities for research on short-term weather prediction in urban

forecast zones could be implemented, the research investment with direct application to WIST needs would be

even greater. Close coordination between the U.S. Weather Research Program and other efforts to support

WIST-relevant R&D is essential.

However, there are two structural reasons why the U.S. Weather Research Program by itself is insufficient to

provide the R&D required by WIST needs. First, its overarching goal constrains it to just a subset of the weather

and environmental elements of interest to WIST user communities, particularly in the context of funding limits

that prevent it from pursuing fully even its highest priorities. Second, the program is intended to complement,

not substitute for, agency-specific implementation programs that move the results of research into operations and

services. Many of the technology development requirements listed in Appendix E are thus outside the intended

scope of this research program.
5-15 

Partnering between federal agencies and the academic community will continue to play a key

role in translating research into practical WIST applications. The Collaborative Science,

Technology, and Applied Research Program (CSTAR) was established to provide structure to

the variety of collaborative research and education efforts sponsored by the NWS. All CSTAR

efforts are meant to enhance scientific interactions leading to a transfer of improved scientific

understanding and technological advances into the total forecast system. CSTAR includes the

NWS Cooperative Institutes, which are long-term agreements between NOAA and a university

to share the costs of an institute focusing on a limited number of agreed-upon research topics.

Also within the CSTAR Program is the Cooperative Program for Operational Meteorology,

Education, and Training (COMET), administered by the University Corporation for Atmospheric

Research. These CSTAR efforts represent important avenues for improving educational

opportunities related to transportation weather and WIST applications. In addition, more than a

dozen NWS Weather Forecast Offices are located on or near university campuses, including five

of the Collaborative Institutes.

The Department of Transportation supports 33 University Transportation Centers, which conduct

research or related support for the nation’s transportation systems. However, only a few of these

centers now focus on weather-related research for surface transportation.

With respect to both general meteorology and transportation systems, these examples show that

an academic research and education infrastructure already exists. What is missing is substantial

commitment within this infrastructure to surface transportation weather and addressing the needs

of WIST users.

Many federal agency laboratories and academic research centers participate in WIST R&D. In

some cases, they are partners in a consortium of investigators and researchers, as in the National

Consortium on Remote Sensing in Transportation, which is addressing infrastructure; traffic

flows; environment; and disaster assessment, safety, and hazards. The consortium includes

representatives from the University of New Mexico’s Earth Data Analysis Center, the University

of Utah’s Center for Natural Technological Hazards, George Washington University’s Space

Policy Institute and Center for Disaster Management, and Oak Ridge National Laboratory’s

Center for Transportation Analysis. The aim of this consortium is to expand applications of

spatial and spectral technologies in transportation. Its strategy is to expedite the development of

innovative remote sensing applications through proof-of-concept and demonstration phases, then

quickly make the successful applications operational and available to commercial entities, which

will become the ongoing suppliers of the information to specialized WIST users. The challenge

for this and similar consortia and their associated technology projects is to serve as bridges

linking the interests of state, local, and federal entities in mapping and spatial information with

the private sector’s capabilities to provide the information in relevant formats and interpretations.

Another aspect of applied R&D is the international nature of transportation problems and

solutions. Many R&D efforts are in progress in Europe and other areas. These efforts and their

results are shared through participation in various national and international meetings and

through publication in the scientific and technical literature. However, mechanisms for more

sustained interaction and cooperation are possible and worth exploring.
5-16 

The ultimate goal in incorporating new

technologies is to put information into the

hands of decision makers when and where they

need it, in forms they can understand and use.

The bottom line is that many avenues for R&D exist. Cooperative planning and participation by

all levels of government, the university research community, and the private sector can leverage

the investments made in research to obtain the greatest benefit for and from the transportation

systems of the future.

Information Technologies

Interest in weather information for surface transportation has its roots in the growth of

information technology, as well as in better observation systems and forecasting. The demand by

transportation managers for more accurate and timely weather information has been stimulated

by innovations in telecommunications, improved computer capabilities at lower prices, and

dissemination via the Internet of weather and environmental information packaged in useful

formats by commercial providers. These technology applications represent just the leading edge

of emerging possibilities. The ultimate goal in incorporating new technologies is to aid

transportation system managers and operators, system maintenance personnel, and vehicle/vessel

operators involved with any mode of surface transportation in making decisions that enhance the

safety and efficiency of their transportation-related activities. This goal requires putting

information into the hands of these decision makers when and where they need it, in forms they

can understand and use.

Users require weather information tailored to their

specific decision or operation. Reliable and timely

information about current and future weather

conditions can enable people to make better

decisions about their activities and contribute to their

safety, as well as improving the efficiency and effectiveness of those activities. Adoption of an

open systems philosophy, together with the recognition and development of decision support

software as a distinct application layer on top of open systems, will facilitate the tailoring of

weather information to meet the diverse and specialized needs of different user groups.

The enabling information technologies have supported applications of weather information in

decision support systems for winter road maintenance and in travel information systems.

Improvements in mesoscale weather prediction models, road condition models, and forecasting

systems that incorporate artificial intelligence have facilitated more extensive use of weather

information in the surface transportation community.

Although current off-the-shelf technologies do not address the information needs of all surface

transportation communities fully, a number of current information technologies and applications

already provide substantial benefits. Examples include the Internet, display and visualization

technologies, wireless communications, and global positioning satellites. Among the services

incorporating these information technologies are pagers, cell phones, NOAA Weather Radio,

weather news and information on cable and broadcast television stations, “511” telephone

advisory services for road information, the FHWA-funded decision support systems described in

Section 1.3.1, and proprietary in-vehicle systems that provide personalized, real-time traffic and

road condition reports. The attributes desired in systems using new technologies include

capabilities for data aggregation and integration, ease of distribution to consumers and
5-17 

businesses, two-way sharing of data with public and private sector partners, and ease of

operation and maintenance of the supporting infrastructure.

Among the emerging information technologies for WIST applications is the use of Dedicated

Short Range Communications (DSRC) to provide safety and traffic advisory information directly

to the traveler in a private vehicle or other transportation conveyance. On-board displays and

audio systems would provide real-time data to the traveler. Prototype systems are being

developed and tested in the United States, Canada, and Europe.

The roadway transportation community has expressed support for the opportunities represented

by concepts such as integration, interoperability, and intermodalism as ways to foster the

development of intelligent transportation systems. The National Intelligent Transportation

Systems Program Plan: A Ten-Year Vision, builds on past major ITS initiatives such as the

national ITS architecture, the Standards Development program, the Metropolitan Model

Deployment Initiative, and others. The stakeholders called upon by this ITS program plan to

contribute to its realization include the public sector at all governmental levels, the private sector,

and the academic research community. The plan describes the impacts of weather on

transportation systems and issues in weather information needs for transportation. Among the

actions it calls for are creation of a Surface Transportation Weather Applications Research

Program and a National Surface Transportation Weather Observing System (ITSA 2002a, pp. 1,

7–11, 44, 52, 55).

There are also significant near-term opportunities to translate technology advances into

operations supporting the MTS. Ensuring safe and efficient port operations is vital to maintaining

the competitiveness of the U.S. port industry and U.S. exports. One key to reducing risks while

increasing efficiency is to invest in the national information infrastructure that supports the

maritime movement of goods and people. This infrastructure includes weather predictions and

forecast models that use both meteorological and oceanographic data to forecast oceanographic

conditions for navigation.

A traffic advisory sign warns

users of Interstate 70 in Denver

that the highway is closed east of

the city due to a winter storm.

Copyright AP Wide World

Photos.
5-18 

5.4.4 Next Steps for Strategic Thrust Area 4

Goal for Translating R&D into WIST Applications. Establish a WIST R&D Program. This

program should be coordinated with and complement the U.S. Weather Research Program, as

well as other R&D programs in transportation weather, including work in progress, planned, or

funded by federal entities, state and local public sector entities, universities, or private sector

organizations.

Coordinating the federal R&D programs relevant to WIST will provide the nation with a

comprehensive, multifaceted R&D effort that addresses information needs of the full range of

current and potential WIST users in surface transportation sectors. In conjunction with this

coordination, a WIST R&D Program should include mechanisms for transitioning research

results and new technology into WIST applications. Special attention should be given to

leveraging research that has linkages, synergy, or applications in other high priority programs

such as homeland security.

This goal emerged over the course of WIST meetings and symposia, as described in Chapter 2.

Potential research topics for a WIST R&D program include the highlights listed in Section 5.4.1.

Appendix E provides a more comprehensive list of applied R&D topics with potential for nearterm payoffs (indicated by an ‘NT’ after the list item).

The following actions are proposed as next steps and enabling mechanisms for Strategic Thrust

Area 4. The order of actions is not chronological; they can and should be undertaken in parallel.

Next Step 4A. Users and providers need access to information about the technology

developments and research initiatives relevant to their WIST needs.

• This information must be structured and presented in ways that allow users to

understand how they can best exploit available and emerging technology and

information resources.

• Access to the information can be facilitated through interdepartmental cooperation at

the federal level, coupled with strategic partnerships and alliances within and among

the weather information provider communities of the public and private sectors.

Next Step 4B. The federal partners in FCMSSR should propose a significant, cohesive

research and development program that will provide the basis for improved, integrated

weather information, tailored to supporting users’ decision processes across all surface

transportation sectors and activities.

5.5 Strategic Thrust Area 5: Providing the Fundamental Knowledge to

Support Future Technology Development and Application

As noted in Section 1.3.2 and overarching theme 4 (Section 4.9.4), substantial benefits to the

nation, in terms of safety, reduced economic losses, and increased productivity, are possible with

(1) better spatial and temporal resolution in both forecasts and observations and (2) better
5-19 

forecast accuracy. This improved observational and predictive information must also be available

to users within their planning and operational lead times. And the information must be provided

through products that users can readily understand and incorporate in their decision processes.

5.5.1 Highlights of Longer-Term Research Topics

From the list in Appendix E of R&D needed to meet WIST user needs, the following bullets

highlight gaps in the knowledge base that will require fundamental research to address WIST

user needs fully.

• High-resolution detection and prediction of roadway and railway conditions in complex

terrains, including interpolation schemes for measurement systems, data fusion

techniques, and numerical models

• Advanced decision support systems that incorporate high-resolution, quantitative models

for complex factors such as the effects of traffic volume on road conditions, snow depth,

snow drift, subsurface moisture near roadways, and effects of chemical–precipitation

mixtures on road temperature and condition

• Data fusion and analysis systems for detecting and forecasting low visibility, at high

resolution and accuracy, from multiple information sources, including ground and space

based sensors and numerical models

• Validated models for the uncertainties, risks, and cost–benefit outcomes involved in

incorporating weather and other environmental/geophysical observations and predictions

in surface transportation decision processes

• Determination of the total observational requirements, including those from

transportation facilities, to achieve the quality of numerical weather prediction sufficient

for all WIST user needs.

With respect to meteorological R&D, whether for observing systems or modeling, the research

focus for WIST is the entire boundary layer of the atmosphere (roughly, up to about 1 km), not

Hazardous materials spills on a

highway require emergency

managers to consider how

weather conditions affect

plume transport and diffusion.

In some cases, such as this

accident during heavy fog on a

coastal highway, weather can

also be a factor in causing the

accident. Copyright AP Wide

World Photos.
5-20 

just ground-level conditions. In addition, much of the needed R&D will require investigating

land-air-water interactions that affect transportation system conditions not represented by

traditional meteorological parameters. Table 2-1, which lists the weather and weather-related

elements identified during development of the WIST Needs Templates, indicates the range of

“weather elements” of interest to WIST users.

As noted in Section 5.4, many of the research topics listed in Appendix E, if promptly addressed,

would produce near-term results of operational value, as well as longer-term results from

continuing R&D efforts. These requirements are shown with both Near Term (NT) and Far

Term (FT) indicators in Appendix E.

5.5.2 Barriers and Challenges

Prior to this WIST study, there was little definitive information on the spatial and temporal scales

required for WIST products to be useful in the decisions and actions of potential users. Nor were

there specific thresholds defined for weather and related elements that impact surface

transportation. The information gathered during this study and compiled in the WIST Needs

templates represents a major advance in defining these thresholds and spatial and temporal

scales. However, more work is needed to determine the scales and thresholds of input data and

computational parameters necessary to provide information products with the reliability, as well

as the spatial and temporal specificity, required by users.

The spatial and temporal resolution of weather information needed for surface transportation

applications in general and for decision support systems in particular is typically in the misoscale

horizontally (grid spacing of 40 meters to 4 km) and in a very shallow layer vertically (from

ground level to about 2 meters above it). To meet operational time lines, updates must be rapid—

on a scale of minutes to hours—and coupled with lead times of 48 hours. These spatial and

temporal requirements present formidable scientific challenges. Meeting them will require

improved understanding in areas such as boundary layer meteorology, misoscale

thermodynamics, the effects of small local variations, probability and statistics, high-resolution

numerical modeling that includes land-air-water interactions, the verification and quality control

of nonstandard data, and the preparation and communication of probabilistic forecasts.

Processing data at these finer scales will require expanded computational capabilities.

5.5.3 Next Step for Strategic Thrust Area 5

Goal for Providing the Fundamental Knowledge Base. Identify and support fundamental

research representing a longer-term investment in acquiring the knowledge base needed to meet

important WIST user needs that cannot be fully satisfied on the basis of current knowledge.

This goal emphasizes the value of including some longer-term research areas, aimed at

addressing limitations in the fundamental knowledge needed to meet WIST user needs, in the

R&D programs discussed in Section 5.4.3. Often, the research questions that are strong

candidates for these longer-term investments are described as “basic research.” However, even

though the increase in knowledge resulting from such research may not deliver operational

results to WIST users in the near term, the topics should be selected and tested for strategic
5-21 

potential in addressing validated needs. Examples of areas where this type of longer-term

investment is warranted are indicated in Appendix E by an ‘FT’ indicator after the research item.

Next Step 5a. Include in the coordinated R&D programs for WIST a substantial level of

fundamental research with strategic potential for expanding the fundamental

knowledge needed to meet WIST users’ needs.

Next Step 5b. The federal agency partners in the FCMSSR should present a unified

rationale to Congress and the Administration for the strategic potential of the

fundamental research topics included in the WIST R&D Program and other

coordinated R&D programs, similar to what has been done in the past for the U.S.

Global Change Program.

5.6 Strategic Thrust Area 6: Expanding Outreach and Education

5.6.1 Barriers and Challenges in WIST Outreach

There are major cultural differences between the meteorology and transportation disciplines. As

noted in Section 4.1.4, potential WIST users vary widely in their knowledge about the

availability and sources of weather information. In the course of this study, there was significant

variation among the transportation sectors, as well as within each sector, in the range and detail

of needs that representative users were able to bring to the effort, particularly in initial meetings.

Understanding how weather affects a transportation activity does not automatically give users an

understanding of how better weather information can benefit the activity. Users need assistance

and training to achieve maximum benefit from applications of weather information.

At the same time, those with training in the meteorological and environmental sciences, as well

as expertise in the technologies and techniques of observing and forecasting weather and related

phenomena of concern to WIST users, must do better at communicating the significance of their

knowledge and technology to the users. A two-pronged approach is essential if “weather

professionals” are to provide the information and tools to support surface transportation decision

processes. Formal training in the conceptual frameworks, operational environments, and

technical systems within which transportation decision makers work should be coupled with

direct experience working with these user communities.

To help with educating WIST users, universities can offer surface transportation weather courses

in programs for transportation management degrees. Training programs for users and managers

of transportation systems that provide emphasis on weather factors and the use of weather

information will clearly benefit the transportation industry and its consumers. Just as important

are courses in both degree programs and continuing education programs that educate

meteorologists and other scientific specialists to understand surface transportation systems and

management processes.

As traveler-oriented weather information services evolve, the general public needs to be

informed about them. Broad support for WIST initiatives can be fostered by communicating the

values of WIST, in improving both transportation safety and economic efficiency, beyond the
5-22 

The vision is to be able to move

anyone or anything, anywhere,

anytime, on time, whatever the

weather may be!

communities of transportation system managers and operators. Outreach to the public served by

these systems can be accomplished through the media and embedded in primary and secondary

(K–12) education. Only through a range of educational activities such as these will the full

potential of WIST applications be realized.

5.6.2 Next Steps for Strategic Thrust Area 6

Goals for WIST Outreach and Education. (1) Incorporate mechanisms for education of

potential WIST users, including interactions between the users and providers of weather

information, in WIST service delivery processes. Include current information on WIST

applications and the value of WIST in transportation systems operations in the training for

surface transportation professionals. (2) Provide and promote educational opportunities for

meteorologists and related professionals to learn about surface transportation systems where

weather and related environmental information can improve system performance. (3) Include

information about WIST applications and ways that the public can access and use WIST in their

own transportation activities in “weather education” outreach to the general public and in school

weather education programs.

Next Step 6. Conduct a WIST Education Forum on the status of and directions for

expanded efforts in, education, training, and outreach for delivery of services and

products to meet WIST user needs. There should be broad participation from the

provider and user communities, as well as from the FCMSSR partners. Include topics

on:

• Mechanisms for education of WIST users

• Opportunities for meteorologists and related professionals to learn about surface

transportation systems

• Outreach to the general public through the media and school programs.

5.7 A Vision for Surface Transportation Weather in the Future

Transportation demand is predicted to double in the next 20

years and triple in 50 years. No substantial increase in the

nation’s transportation infrastructure is planned. Innovative

solutions to meet this anticipated growth in demand include

new technology and concepts, such as the expansion of

information technology, nanotechnology, and technologies that are more energy-efficient and

environmentally friendly. Implementing solutions will require a joint effort that includes critical

roles for the Congress, state and local government, industry, labor, academia and

nongovernmental organizations, all working together to set priorities and solve problems.

This study envisions a national capability to provide timely, accurate, and relevant information

on surface transportation weather. This information will be tailored to specific transportation

needs, allowing all users to anticipate and exploit the weather, for maintaining the national

surface transportation infrastructure efficiently and for moving anyone or anything, anywhere,

anytime, on-time, efficiently, safely, and securely.
5-23 

Technologies for collecting, storing, processing, communicating, and managing information can

revolutionize transportation. These technologies generate information on physical parameters at

a given time; temporal trends in these parameters; geographic location of transport carriers,

goods, and physical conditions of interest; and the overall environmental and situational context

of the transportation system. They will be included in all facets of transportation—vehicles,

vessels, and infrastructure. Not only will they improve efficiency in the individual transportation

sectors; they will improve the efficiency of interfaces between the sectors and the efficiency of

the nation’s entire intermodal transportation system. The result will be true intermodal service,

providing transportation options to maximize safety, convenience, and efficiency for travelers by

facilitating seamless transitions in the use of all transportation modes. However, most of these

technologies will require a much more advanced and capable weather information support

system than is currently planned or funded for the future.

Weather information must be an integral part of transportation systems of the future that can

safely and economically move anyone and anything, anywhere, anytime, on time. This vision is

compatible with the FHWA strategic goals of improving the infrastructure and operations of the

highway system in a manner that promotes productivity, safety, and national security, as well as

mobility without jeopardizing the quality of the natural environment. Tailored weather

information will facilitate decision processes in a transportation system with far fewer fatalities

or injuries per mile traveled.

The WIST user needs identified by this study (see Appendix B and Chapter 4) set the stage for

the vast improvements in weather information products and services that will be required for

decision support in activities across the spectrum of surface transportation systems. The future

WIST infrastructure will evolve from developments that exploit the open Intelligent

Transportation System and the national weather information infrastructure. Environmental

sensors and networks in parallel with explosive growth in computer and communications

capabilities will provide the basis for a high-resolution weather data collection system. The

resulting database, coupled with advanced numerical and transportation models and modernized

distribution systems, will make real-time, accurate, and timely weather information available for

integration with other key information elements useful to every traveler and every transportation

system decision maker.

For this advanced WIST infrastructure and array of tailored WIST services and products to

become a reality, attention must be given to the overall system architecture. This architecture

must comprehend the optimal mix of weather observations with mesoscale and misoscale

modeling; the definition, development and testing of tailored products and information; and the

infrastructure that supports the entire system. Explicit policy guidance will be needed to resolve

public and private sector issues regarding roles and responsibilities in the generation and

application of weather information. Planning and implementation should also provide for

education, outreach, and advocacy for users and providers of WIST services and products.

The vision of a vastly improved, safe, and efficient transportation system requires WIST users

and providers to leverage research plans and funding in a mutually beneficial way. These

communities must work together to apply the results of weather research and technology

development to the spectrum of decision processes involved in surface transportation activities.
5-24 

Adopting, advocating, and implementing the thrust area goals and next steps outlined in this

report can provide a basis for achieving the vision of moving anyone or anything, anywhere, any

time, on time, whatever the weather may be.
Ref-1

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Weather Information for Surface Transportation

A - 1

Appendix A

Entities Participating in WIST Needs

Identification and Validation
A-2

Participating Entities Transportation Sectors

Federal Departments and Agencies Road Rail

Marine

Transportation

System

Pipeline

Systems T

Department of Transportation

Federal Aviation Administration Federal Highway Administration XFederal Railroad Administration XFederal Transit Administration X X X Maritime Administration XNational Highway Traffic Safety Admin. X XResearch & Special Programs Administration X X X X  Office of Pipeline Safety XU.S. Coast Guard X

Department of Energy

National Transportation Program X X X Power Marketing Administration X

Department of Defense

USTRANSCOM X X X  Military Traffic Mgmt. Command X X X U.S. Air Force X U.S. Army X XU.S. Navy X Defense Logistics Agency X

Department of Commerce (NOAA)

National Ocean Service XNational Weather Service X X X X NOAA Corps X

Department of Interior

Park Service X XBureau of Reclamation X XU.S. Geological Survey X

Department of Agriculture

Agricultural Marketing Service X X X X Farm Service Agency X X X X Forest Service X X X X Office of Chief Economist X X X X 

Environmental Protection Agency X XFederal Emergency Management Agency X X XNational Aeronautics and Space Administration X X XNuclear Regulatory Commission X X XU.S. Postal Service X X X
A-3

Participating Entities Transportation Sectors

State Departments of Transportation a Road Rail

Marine

Transportation

System

Pipeline

Systems T

State Departments of Transportation (Western Region)

Alaska XArizona XCalifornia XIdaho XNevada XUtah XWashington X

State Departments of Transportation (Central Region)

Iowa XIllinois XKentucky XMinnesota XNorth Dakota XSouth Dakota X

State Departments of Transportation (Southern Region)

Arkansas XLouisiana XMississippi XTennessee X

State Departments of Transportation (Eastern Region)

Connecticut XMaryland XMaine XNew Hampshire XNew York XPennsylvania XSouth Carolina XVirginia XVermont X

a Various state departments of transportation have responsibilities in other sectors than roadways. However, during this initial round of 

template development, they were involved only in validating the roadways template.
A-4

Participating Entities Transportation Sectors

Transit Authorities Road Rail

Marine

Transportation

System

Pipeline

Systems T

Transit Authorities (Western Region)

Alaska – Anchorage Alaska – Fairbanks Arizona – Phoenix California - Los Angeles California – Oakland California – Sacramento Hawaii – Honolulu Montana - Great Falls Oregon – Salem Utah - Salt Lake City Washington - Bremerton 

Transit Authorities (Central Region)

Colorado – Denver Illinois – Rockford Illinois - Centrailia Michigan - Grand Rapids Minnesota - Minneapolis/St. Paul Missouri - Kansas City Nebraska - Omaha Wisconsin - Milwaukee Wyoming - Cheyenne 

Transit Authorities (Southern Region)

Alabama - Birmingham Florida - Palm Beach Georgia - Atlanta Oklahoma - Oklahoma City Tennessee - Memphis Texas - Corpus Christi Texas - Fort Worth 

Transit Authorities (Eastern Region)

Connecticut - Hartford Maryland - Montgomery County Massachusetts - Boston North Carolina - Charlotte North Carolina - Research Triangle New Jersey - Newark New York - Brooklyn Ohio - Cleveland Ohio - Dayton Pennsylvania - Philadelphia South Carolina - Charleston Virginia - Hampton Roads Virginia - Potomac & Rappahannock 
A-5

Participating Entities Transportation Sectors

Trade Associations and Private Sector Entities Road Rail

Marine

Transportation

System

Pipeline

Systems T

Trade Associations (Road & Transit)

Intelligent Transportation Society of America X American Public Transportation Assn American Assn of State Highway & Trans. Officials X American Automobile Assn X American Trucking Assn XAmerican Bus Assn X American Traffic Safety Services Assn X Intermodal Assn of North America X X XMotor Freight Carriers Assn XNational Assn of Fleet Administrators XComm Vehicle Safety Alliance XTruckload Carriers Assn XNational Assn of Home Builders X

Trade Associations (Rail)

Assn of American Railroads XIntermodal Assn of North America X X X

Rail Industry

Burlington Northern Santa Fe XCanadian National XCanadian Pacific Railway XConsolidated Rail Corporation (CONRAIL) XCSX Transportation XMetra (Northeast Illinois Reg. Commuter Railroad Corp. XNorfolk Southern Corp XUnion Pacific Railroad X

Trade Associations (Marine Transportation System)

American Assn of Port Authorities (AAPA) X

Port of Portland, OR X

Intermodal Assn of North America X X XWeathernews/Ocean Routes Inc XTropical Prediction Center/National Hurricane Center XAmerican Boating Assn XJersey Coast Anglers Assn XThe American Waterways Operators (AWO) XIngram Barge Co. X

Trade Associations (Pipeline Systemss)

American Petroleum Institute XAssn of Oil Pipelines XIndependent Petroleum Assn of America XInterstate Natural Gas Assn of America XNatural Gas Supply Assn X
A-6

Participating Entities Transportation Sectors

Trade Associations and Private Sector Entities

(Continued) Road Rail

Marine

Transportation

System

Pipeline

Systems T

Energy Industry (Pipeline Systems)

Exxon/Mobil XEquilon Pipeline Co. XChevron XPlantation Pipe Line Co. XColonial Pipeline Co. XMN Office of Pipeline Safety XBuckeye Pipeline Co. X

Professional Associations

National State Troopers Assn X 
A-7

Participating Entities Transportation Sectors

Airports, Airlines, School Districts Road Rail

Marine

Transportation

System

Pipeline

Systems T

Regional Airports (Western Region)

Alaska - Anchorage (ANC) Arizona - Phoenix (PHX) California - Los Angeles (LAX) Utah - Salt Lake City (SLC) Washington - Seattle (SEA) 

Regional Airports (Central Region)

Colorado- Denver (DIA) Illinois - Chicago (ORD) Minnesota - Minneapolis/St. Paul (MSP) Nebraska - Omaha (OMA) Nebraska - Offutt AFB (OFF) North Dakota - Grand Forks (GFK) 

Regional Airports (Southern Region)

Florida - Miami (MIA) Georgia - Atlanta (ATL) Texas - Dallas/Fort Worth (DFW) 

Regional Airports (Eastern Region)

Massachusetts - Boston (BOS) North Carolina - Charlotte (CLT) New York - New York (JFK) Virginia - Andrews AFB (ADW) Virginia - Dulles (IAD) Washington, DC (DCA) 

Airlines

American Delta Northwest United 

School Districts

Arizona – Phoenix Georgia – Atlanta Illinois – Chicago Louisiana - New Orleans Minnesota – Minneapolis Mississippi – Jackson Missouri - Kansas City Montana – Bozeman North Carolina – Charlotte Ohio – Cleveland Oregon – Salem Utah - Salt Lake City Virginia – Fairfax 
Weather Information for Surface Transportation

Appendix B

WIST Needs Templates by Sector

B-1 Roadways

B-1.1 Federal Highways

B-2 Long-Haul Railways

B-3 Marine Transportation System

B-4 Pipeline Systems

B-5 Rural and Urban Transit Systems

B-6 Airport Ground Operations
Weather Information for Surface Transportation

WIST Needs Template Column Headings

Weather Element. A weather element is a particular weather condition or a consequence of

weather conditions that WIST participants identified as affecting (1) transportation system

operations (e.g., road or railway maintenance; traffic management on rail, road, or marine

transportation systems) or (2) the safety, economic value, or efficiency (time as well as cost) of

transportation activities using those systems (e.g., ship or barge movement on the MTS, truck

and car movement on roadways). The categories of weather elements included in the templates

are precipitation elements; temperature-related elements; thunderstorm-related elements; winds;

visibility; tropical cyclone, sea state, and ice (on waterways); and miscellaneous elements. The

individual weather elements in each category are listed in Table 2-1.

Threshold. The responses to the initial WIST questionnaire (see Chapter 2) emphasized the

importance of specific thresholds at which a weather element affects a transportation activity or

(in the case of multiple thresholds) affects it differently. In some cases, any occurrence of a

weather element has impacts and requires action. For other elements, thresholds are critical to

defining the users’ information need.

(Sector) Activity. A sector activity is a grouping of functionally similar or identical WIST users

within a transportation sector. For example, WIST user activities within the roadways sector

include road maintenance operations, bus operations, and state police. The long-haul railways

sector has activities for railroad stations and depot operations. Among the activities in the Marine

Transportation System are inland waterway recreational boating and open water cargo/freight

operations. The rationale for delineating an activity within a sector was either the uniqueness of

the activity’s needs and requirements or differences in institutional operations among activities

within a sector. Each template begins with a table of sector activity descriptions. (The same

descriptions appear in Chapter 4.)

Impacts. The Impacts column lists potential economic and safety consequences of a particular

weather element, once the stated threshold is reached, on the stated sector activity or activities.

Actions. The Actions column lists mitigating activities and key decisions available to WIST

users in the stated sector activity, if they receive accurate information about the stated weather

element with the lead time shown in the last column. Impacts and actions are discussed by sector

in Chapter 4.

Lead Time. The forecast lead time required for users’ to take action and make decisions is a

critical factor in supporting surface transportation with weather information. For the WIST needs

identification, lead time is defined as the advance warning prior to an event. This advance

warning gives the decision maker the time needed to make the necessary preparations to

minimize the effects of the weather on the specified event or activity.
Weather Information for Surface Transportation

Appendix B–1

Roadway Sector WIST Needs Template
Weather Information for Surface Transportation

Roadway Sector Activities

Road maintenance. This activity is generally where the requirements of the state transportation departments are

compiled. It includes road surface treatment for snow and ice control in the winter, as well as road and

infrastructure maintenance year-round to repair damage.

Truck operations. The primary example for this activity is commercial trucking operations, both local and long

haul.

Fleet utility and transport vehicle operations. This activity includes small to medium size fleets of utility

vehicles, such as those maintained by telephone or cable television companies, as well as the large, nationwide

fleets of mail and parcel delivery vehicles.

Bus operations. This activity is intended to cover primarily long-haul bus operations, such as interstate travel,

rather than school buses or local transit system buses, both of which are covered by the Rural and Urban Transit

Operations sector.

Private vehicle operations. Private vehicle operators, daily commuters, long-distance travelers, and local drivers,

as well as rental car operators, are included in this activity.

State/local emergency managers. This activity encompasses emergency managers at state and local levels.

State police. Although state police and highway patrol entities provided the input on WIST needs for this activity,

the information is generally valid for law enforcement and public safety officials anywhere with roadway traffic

safety responsibilities.

Forest Service. The roadway operations of the U.S. Forest Service role are limited to unimproved roads under its

jurisdiction within national forests and grasslands. But the ways in which the weather affects these roads has

major impact on all the uses of these areas.

Special Groups

NASA spacecraft and equipment transport. NASA’s principal concern with roadways is in transporting

spacecraft and components by land routes between its various centers and the launch facilities.

Power generating operations. The WIST needs of the power marketing administrations (see Section 3.1.2) are

limited to road conditions that affect the ability of repair crews in utility vehicles to reach transmission

lines and facilities.

Manufactured home transport. This specialized activity has WIST needs that represent the general class of

high-profile vehicles, which have special sensitivities to wind and other weather elements, such as those

that affect tire traction.
Weather Element Threshold Activity Impacts Action 

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, loss of communications/power, slope instability (avalanche risk)

Advise operators, begin preparation the public through press releases to awareness and allow adjustment to 

threatened area, select treatment str

Operational and travel delays, increased workload Anti-icing, de-icing treatment of road

deploy and track treatment assets. Achemicals/abrasives, manage traffic debris and repair damage.

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Possible loss of control, endangering other drivers Advise operators and reduce speed 

necessary.

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been treated for ichaul) or delay movement. Prepositiotransport site and transport earlier to impacts.

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Advise operators, reschedule, or rer

Bus operations Increased safety risk to operators and passengers, 

injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property

Implement preparation procedures, Advise operators to drive with extremor restrict operations (especially on hoperations as appropriate. Advise paradio system. Clear station parking l

Private vehicles Safety risk to motorists, travel delays Advise motorists, reschedule, reroutState emergency management

Safety risk to motorists, hazardous cargo risks Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

U.S. Forest Service Closed roads, blocked roads, recreationists (e.g. 

hikers, campers) trapped or stranded, threats to safety and survival

Warn campers/hikers to evacuate thInitiate search and rescue operationRepair/reopen closed roads.

Power generating operations

Impaired mobility of commuters and line repair operations, line repair accomplished by overland dispatch of personnel, potential for "line conductor galloping" (a power distortion that may occur during transition of precipitation from rain to wet snow and then to snow or ice) 

Alert and advise commuters and line 

Structure Ice Accumulation (inches)

Any Road maintenance Loss of communications/power, property and 

structural damage, safety risk 

Select and implement treatment stradebris and repair damage.

Weather Needs for Roadway Transportation

Freezing Precipitation (ice) Any Road maintenance 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Pavement Ice Accumulation (inches)

Any Road maintenance Impaired mobility, loss of stability/maneuverability, 

loss of traction, pavement damage, pavement temperature, safety risk, snow removal/ice treatment operations

Select and implement snow removatreatment strategy. Remove debris a

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Advise operators, begin preparation equipment, crew planning, shift chanreassignment and deployment. Warn press releases to ensure public awaadjustments to travel plans. Predict tselect treatment strategy.

Operational delays, increased workload Conduct snow fighting operations. P

track treatment assets. Apply treatmchemicals/abrasives, manage traffic 

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Possible loss of control, danger other drivers. Advise operators and reduce speed 

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, plan for movement speeds, reroute (long haumovement. Preposition cargo at air ttransport earlier to avoid weather im

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Advise operators, reschedule, rerout

Bus operations Increased safety risk to operators and passengers, 

injuries and resulting claims, traffic congestion, vehicle

damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delays of facility maintenance

Advise operators, reschedule, reroutto drive with extreme caution. Modify

(especially on hills), suspend operatregions). Advise passengers via bus station parking lots and platforms.

Private vehicles Safety risk to motorists, travel delays Advise motorists, reschedule, reroutState emergency management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

U.S. Forest Service No significant impact Advise recreationists. Power generating operations

Impaired mobility of commuters and line repair operations, line repair accomplished by overland dispatch of personnel, potential for "line conductor galloping" (a power distortion that may occur during transition of precipitation from rain to wet snow and then to snow or ice) 

Alert and advise commuters and line Advise operators, begin preparation equipment, crew planning, shift chanreassignment and deployment. Warn press releases to ensure public awaadjustments to travel plans. Predict tselect treatment strategy.

Frozen Precipitation >2 to <8(snow, inches)

Road maintenance Safety risk to maintenance personnel and motorists, 

travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Frozen Precipitation Road maintenance (snow, inches)

Any to <2 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Prepare, deploy, and track treatmentreatment chemicals/abrasives, plow traffic flow, implement tire chain conaccess to designated vehicle types, roadways/bridges.

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Possible loss of control, danger to other drivers Advise operators. Reduce speed or 

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, plan for movement speeds, reroute (long haumovement. Preposition cargo at air ttransport earlier to avoid weather im

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Advise operators, reschedule, rerout

Bus operations Increased safety risk to operators, passenger injuries 

and resulting claims, traffic congestion, vehicle damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delayed facility maintenance

Advise operators, reschedule, reroutto drive with extreme caution, modify operations (especially on hills), suspsome regions). Advise passengers vsystem. Clear station parking lots an

Private vehicles Safety risk to motorists, travel delays Advise motorists, reschedule, reroutState emergency management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

U.S. Forest Service No significant impact Advise recreationists. Power generating operations

Impaired mobility of commuters and line repair operations, line repair accomplished by overland dispatch of personnel, potential for "line conductor galloping" (a power distortion that may occur during transition of precipitation from rain to wet snow and then to snow or ice) 

Alert and advise commuters and line Advise operators, begin preparation equipment, crew planning, shift chanreassignment and deployment. Warn 

press releases to ensure public awaadjustments to travel plans. Predict tselect treatment strategy. Implement snow fighting, tire chain cPrepare, deploy, and track treatmentreatment chemicals/abrasives, plow traffic flow (restrict access to designrestrict access to roadways/bridges, roadways/bridges).

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, loss of communications/power, slope instability (avalanche risk)

Frozen Precipitation Road maintenance (snow, inches) 

 >8 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Restrict or suspend operations, resc

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been plowed, rerodelay movement. Preposition cargo and transport earlier to avoid weathe

Bus operations Increased safety risk to operators, passenger injuries 

and resulting claims, traffic congestion, vehicle damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delayed facility maintenance

Advise operators, begin preparation implement snow routes. Put snow roappropriate. Advise operators to drivcaution. Modify or restrict operations hills), suspend operations as approppassengers via bus radio system. Clots and platforms.

Private vehicles Safety risk to motorists, travel delays Restrict/suspend travel, reschedule, State emergency management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

 >8 (primarily 

significant early snowfall)

U.S. Forest Service Closed roads, blocked roads, recreationists (e.g. 

hikers, campers) trapped or stranded, threats to safety and survival

Warn campers/ hikers to evacuate thInitiate search and rescue operationRepair/reopen closed roads.

 >8 Power generating 

operations

Impaired mobility of commuters and line repair operations, line repair accomplished by overland dispatch of personnel, potential for "line conductor galloping" (a power distortion that may occur during transition of precipitation from rain to wet snow and then to snow or ice) 

Alert and advise commuters and line 

Any Safety risk to maintenance personnel and motorists, 

travel delays, loss of visibility, loss of traction (Winds >15 mph can lead to blowing snow and drifting in some areas. The amount of snow already on the ground may not be the determining factor; if snow storage areas are full, even a few inches can cause drifting problems. Drifting snow can cause continuous and prolonged clearing operations, which strain manpower resources.)

Consider road closures and treatmepreparation procedures for equipmeshift changes, geographical reassigndeployment. Warn public through prensure awareness and allow adjustmPredict threatened area. Construct astructural snow fences. 

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Road maintenance 

 >8

Drifting Snow (inches, must include wind speed and direction)

 >8

Select treatment strategy. Implementire chain control operations. Prepartreatment assets. Plow snow, apply chemicals/abrasives. Modify lane co

snow removal/ice treatment operatio

Operational delays, increased workload, loss of visibility, loss of traction, lane obstruction, impaired mobility
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Restrict or suspend operations, resc

NASA (Goddard) spacecraft and equipmenttransport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been plowed, rerodelay movement. Preposition cargo and transport earlier to avoid weathe

Bus operations Increased safety risk to operators, passenger injuries 

and resulting claims, traffic congestion, vehicle damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property

Advise operators, begin preparation implement snow routes. Put snow roappropriate. Advise operators to drivcaution. Modify or restrict operations hills), suspend operations as approppassengers via bus radio system. Clots and platforms.

Private vehicles Safety risk to motorists, travel delays Restrict or suspend travel, rescheduState emergency management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

Power generating operations

Impaired mobility of commuters and line repair operations, line repair accomplished by overland dispatch of personnel, potential for "line conductor galloping" (a power distortion that may occur during transition of precipitation from rain to wet snow and then to snow or ice) 

Alert and advise commuters and line 

Snow Accumulation Observation (inches)

Any Road maintenance Drifting snow, impaired plowing, lane obstruction, loss 

of stability/maneuverability, loss of traction, effects of pavement temperature on snow pack, slope instability (avalanche risk)

Prepare, deploy, and track treatmentreatment chemicals/abrasives, manRemove debris and repair damage.

Snow Drift Levels Observation (inches)

Any Road maintenance Impaired plowing, lane obstruction Select treatment strategy. 

Roadway Snow Depth Observation (inches)

Any Road maintenance Loss of traction, impaired mobility, effects on snow 

removal/ice treatment operations

Select treatment strategy. 

Roadway Snow Pack Depth Observation (inches)

Any Road maintenance Loss of traction, impaired mobility, effects on snow 

removal/ice treatment operations

Select treatment strategy. 

Adjacent Snow Depth Observation (inches)

Any Road maintenance Drifting snow, roadway snow depth Select treatment strategy. 

Snow/Ice Bonding Observation (inches)

Any Road maintenance effects on snow removal/ice treatment operations Select treatment strategy. 

Advise operators, travelers, planning threatened area. Begin preparation pdrainage where blocked.

Finalize decisions. 

Heavy Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Liquid Precipitation Any (inches)

Road maintenance Safety risk, maintenance activity delays, DOT 

operational activity delays, public travel delays, loss of visibility, decreased traction and stability/ maneuverability, lane obstruction or submersion, road 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Any Driveaway-towaway 

(manufactured home transport) 

Possible loss of control, danger to other drivers Some states prohibit travel if roadwa

Heavy Fleet utility and transport 

vehicle operations

Safety risk, schedule delays Modify/restrict operations, reschedu

Heavy NASA (Goddard) 

spacecraft and equipment

Transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow moreroute (long haul) or delay movemecargo at air transport site and transpweather impacts.

Heavy Bus operations Increased safety risk, traffic congestion, vehicle 

damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delayed maintenance o

facilities, fleet, and bus stops

Modify or restrict operations (rescheAdvise operators of wet road conditipooling water. Advise operators to dcaution.

Heavy Private vehicles Safety risk, travel delays Modify or restrict travel, reschedule, Heavy State emergency 

management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

Heavy State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

Heavy U.S. Forest Service Safety risk to motorists, storm water on roadways, 

culverts washed away by down-hill cascading, roads washed away, recreational activities and timber cutting halted, people trapped in remote areas

Initiate storm patrols. Pre-stage equpersonnel to prevent damage during equipment after event for emergency roadways.

Precipitable Water Vapor Observation (inches) 

Any Observation 

(by satellite imagery interpretation)

Precipitation patterns and rates Predict threatened area, select treat

Begin preparations, plan detour routPlan for contingencies, issue alerts. Conduct local mobilization. Advise trroads, prepare to monitor/induce dra

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment, Delay, postpone, reschappropriate.

Driveaway-towaway (manufactured home transport) 

Impassable roads Avoid flooded areas. 

Fleet utility and transport vehicle operations

Safety risk, schedule delays Restrict or suspend operations, resc

NASA (Goddard) spacecraft and equipmenttransport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft/vehicles/equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow moreroute (long haul) or delay movemecargo at air transport site and transpweather impacts.

Bus operations Increased safety risk, traffic congestion, vehicle 

damage risk, routes may require detours, traffic accidents, increased risk of damage to busses/property, delayed or suspended bus service in affected areas, notification of road authorities and public relations required

Restrict, reschedule, reroute, or susAdvise operators, roadway authoritierelations of real time road conditionswhere flooding may be occurring or is high.

Private vehicles Safety risk, travel delays Restrict or suspend travel, reschedu

Flooding Road maintenance Safety risks, road submersion, loss of life and property

road damage, bridge damage, travel delays

Any
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

State emergency management

Safety risk to motorists, hazardous cargo Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.

U.S. Forest Service Safety risk to motorists, storm water on roadways, 

culverts washed away by down-hill cascading, roads washed away, recreational activities and timber cutting halted, people trapped in remote areas

Initiate storm patrols. Pre-stage equpersonnel to prevent damage during equipment after event for emergency roadways.

Advise operators, advise travelers. Cease refueling, restrict or suspend 

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Fleet utility and transport vehicle operations

Safety risk, damage risk, operational delays Advise operators, cease refueling, re

outdoor activities.

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays

Advise transport operators, reroute (movement. If underway, take evasivappropriate.

Bus operations Safety risk, damage risk, operational delays Advise operators, cease refueling, re

outdoor activities.

Private vehicles Safety risk, damage risk, travel delays Advise operators, cease refueling, re

outdoor activities.

State emergency management

Safety risk, damage risk, hazardous cargo vulnerability Advise operators, cease refueling, re

outdoor activities.

State police Increased workload due to hazardous travel conditions Advise operators, cease refueling, re

outdoor activities.

U.S. Forest Service Safety risk to workforce, often no communications 

mechanism to get lightning warnings to forest service workers (Workers sometime travel as much as 2 days into remote forest areas.)

When communications (e.g. Forest Savailable, advise field personnel to t

Any Power generating 

operations

efficient power transmission impaired or interrupted Alert operators and line repair perso

Predict threatened area, prepare to and evacuation plans, advise traveleSelect treatment strategy, advise optravelers.

>1/4 inch, <5 miles

Road maintenance Safety risk, hail damage Advise operators, suspend outdoor oTruck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Possible hail damage to manufactured home Change route and/or adjust speed to 

Fleet utility and transport vehicle operations

Safety risk, hail damage, schedule delays Advise operators, suspend travel, re

Any size, <5 miles

Any size, <5 miles

Thunderstorms with Hail (hail size and proximity to route or operational area)

Safety risks and travel delays, loss of visibility, loss of traction, impaired mobility, lane obstruction, loss of life/property, loss of communications/power

Road maintenance 

Thunderstorms with Lightning (proximity to route or operational area in miles)

Road maintenance Loss of life, property damage, loss of 

communications/power, safety risk, maintenance activity delays, travel delays

<5 miles
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

NASA (Goddard) spacecraft and equipmenttransport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays

Advise transport operators, reroute (movement. If underway, take evasivappropriate.

Bus operations Safety risk, hail damage, schedule delays Advise operators, suspend travel, rePrivate vehicles Safety risk, hail damage, travel delays Advise motorists, suspend travel, reState emergency management

Safety risk, hail damage Advise operators, suspend outdoor a

State police Increased workload due to hazardous travel conditions Advise operators, suspend outdoor aU.S. Forest Service Safety risk to workforce, often no communications 

mechanism to get hail warnings to forest service workers (Workers sometime travel as much as 2 days into remote forest areas.)

When communications (e.g. Forest Savailable, advise field personnel to tis available.

Any size, <5 miles

Power generating operations

Impairs or interrupts efficient power transmission Alert operators and line repair perso

Predict threatened area, advise opeReview and implement warning and Advise operators and travelers, suspoperations. 

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Loss of driver and cargo Avoid at all costs. 

Fleet utility and transport vehicle operations

Safety risk, damage to cargo, schedule delays Advise operators, suspend travel, re

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays

Advise transport operators, reroute (movement. If underway, take evasivappropriate.

Bus operations Safety risk, damage to cargo, schedule delays Advise operators, suspend travel, rePrivate vehicles Safety risk, damage, travel delays Advise motorists, suspend travel, reState emergency management

Safety risk, damage Advise operators, suspend outdoor a

State police Increased workload due to hazardous travel conditions Advise operators, suspend outdoor oU.S. Forest Service Access roads blocked by debris and fallen timber, 

valuable timber blown down (Downed timber requires timely salvage before its value is lost.)

Respond immediately to clear roadwsalvage of downed timber.

Observation U.S. Forest Service Blocked roads, downed valuable timber Determine where downed timber and 

may have occurred in remote areas on visual observations and field repousing weather radar, etc.

Road maintenance Credibility of evacuation orders, flood risk, loss of life, 

property damage, road damage, loss of visibility, loss of traction, impaired mobility, lane obstruction/ submersion, loss of communications/power

Predict threatened area, select treatmobilize maintenance personnel, imand evacuation plans, issue evacuatoutflow devices, manage traffic flowrepair damage.

<20 miles

Severe Storm Cell <20 milesTrack—Location, Direction, Speed, Severity (proximity to route or operational area in miles)

Safety risks and travel delays, loss of visibility, loss of traction, impaired mobility, lane obstruction, loss of life

and property, loss of communications/power

Thunderstorms with Tornado <10 miles Road maintenance 

(proximity to route or operational area in miles) 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

U.S. Forest Service Trapped, stranded, injured recreationists Issue warnings and advisories. Impl

or search and rescue plans as nece

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays

Advise transport operators, reroute (movement. If underway, take evasivappropriate.

Major Storms 

Road maintenance Safety risks and travel delays, loss of visibility, loss of 

traction, impaired mobility, lane obstruction/ submersion, loss of life, property damage, loss of communications/power 

Predict threatened area, advise opesuspend outdoor operations, select tImplement warning and evacuation pmaintenance forces.

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

U.S. Forest Service Trapped, stranded, injured recreationists Issue warnings and advisories. Impl

rescue and evacuation plans as nec

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been treated for ic(long haul) or delay movement. Preptransport site and transport earlier to impacts.

Road maintenance Safety risks and travel delays, loss of visibility, loss of 

traction, impaired mobility, lane obstruction/ submersion, loss of life, property damage, loss of communications/power 

Predict threatened area, advise opesuspend outdoor operations, select timplement warning and evacuation pmaintenance forces.

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

U.S. Forest Service Trapped, stranded, injured recreationists Issue warnings and advisories. Impl

rescue and evacuation plans as nec

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been treated for ic(long haul) or delay movement. Preptransport site and transport earlier to impacts. 

Road maintenance Safety risks and travel delays, loss of visibility, loss of 

traction, impaired mobility, lane obstruction/ submersion, loss of life, property damage, loss of communications/power 

Predict threatened area, advise opesuspend outdoor operations, select timplement warning and evacuation pmaintenance forces.

<50 miles

>74 mph, <50 miles>39 mph to < 74 mph, <50 miles

Blizzard—35 mph Sustained Winds, Visibility <1/4 mile, 

Blowing Snow (proximity to route or operational area in miles)Hurricane Force Winds (wind speed in mph and proximity to route or operational area in miles)Tropical Storm Force Winds (wind speed in mph and proximity to route or operational area in miles)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

U.S. Forest Service Trapped, stranded, injured recreationists Issue warnings and advisories. Impl

rescue and evacuation plans as nec

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow mowhen roads have been treated for ic(long haul) or delay movement. Preptransport site and transport earlier to impacts.

General Weather/Environmental Parameters

Variable, based on impact criteria

Road maintenance Air quality, loss of communications/power, 

precipitation type, pavement temperature, slope instability (avalanche risk), snow removal/ice treatment operations

Advise operators, monitor surface moperations.

Variable, trends and ranges based on impact criteria

Power generating operations

Power transmission loads and capacity affected by temperature extremes

Advise managers, operators, and linAdvise operators, monitor personneequipment stress.

Take prescribed actions 

>85 Truck operations Health and safety risk, engine/equipment heat stress Advise operators, monitor personne

equipment stress.

>85-90 Driveaway-towaway 

(manufactured home transport) 

Possible tire blow out on trailer Reduce speed and check tire pressu

>85 Fleet utility and transport 

vehicle operations

Health and safety risk, engine/equipment heat stress Advise operators, monitor personne

equipment stress.

Variable, based on cargo humidity requirements 

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment)

Advise transport operators, ensure sconditioning equipment available to humidity requirements. 

>85 Bus operations Health and safety risk, engine/equipment heat stress Advise operators, monitor personne

equipment stress. Ensure air conditioperating properly.

>85 Private vehicles Health and safety risk, engine heat stress Advise motorists. 

>85 State emergency 

management

Health and safety risk, engine/equipment heat stress Advise operators. 

>85 State police Health and safety risk, engine/equipment heat stress Advise operators. 

Advise operators, modify/restrict opeTake prescribed actions. 

Road maintenance Health and safety risk, engine/equipment heat stress

>110 Road maintenance Health and safety risk, engine/equipment heat stress

Air Temperature 

(degrees F) 

>85-95

Air Temperature 

(degrees F)

Air Temperature 

Including Maximum and Minimum (degrees F)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate.

Fleet utility and transport vehicle operations

Health and safety risk, engine/equipment heat stress Advise operators, modify/restrict ope

Bus operations Health and safety risk, engine/equipment heat stress Advise operators, monitor personne

equipment stress. Ensure air conditioperating properly.

Private vehicles Health and safety risk, engine heat stress Advise motorists to modify or restrict State emergency management

Health and safety risk, engine/equipment heat stress Advise operators, modify/restrict ope

State police Health and safety risk, engine/equipment heat stress Advise operators, modify/restrict ope

Provide early warning, advise operaMonitor surface moisture.Begin treatment actions as appropria

Truck operations Safety and health risks, potential operational delays Advise operators, monitor surface mDriveaway-towaway (manufactured home transport) 

loss of control on icy roads, trailer handling difficulties on changing surface conditions.

Advise operators to adjust speed or 

Fleet utility and transport vehicle operations

Safety and health risks, potential operational delays Advise operators, monitor surface m

Bus operations Safety and health risks, potential operational delays Advise operators, monitor surface mPrivate vehicles Safety and health risks, potential operational delays Advise operators, monitor surface mState emergency management

Operations affected by ice formation Advise operators, monitor surface m

State police Operations affected by ice formation Advise operators, monitor surface mU.S. Forest Service Logging hauling operations on frozen/snow packed 

roads affected by melt/thaw (Thawing may penetrate/damage structural support of roads and shut down heavy truck hauling.)

Place thermistors in roads to monitoroad integrity.

Variable, based on temperature and impact criteria

Road maintenance Precipitation type, fog formation, air quality, slope 

instability (avalanche risk), snow removal/ice treatment operations

Predict threatened area, select treatadvise operators. Monitor surface moperations.

Variable, based on cargo humidity requirements 

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (Spacecraft, vehicles, and equipment must be maintained at specified humidity thresholds.)

Advise transport operators, ensure sconditioning equipment available to humidity requirements. 

Air Temperature Change Rate (degrees F per 24 hours)

Approx. 60o Road maintenance Precipitation type, pavement temperature, pavement 

buckling damage due to rapid expansion and contraction

Predict threatened area, select treatRepair roadways.

Time and Air Temperature Integrals (heating/cooling degree days)

Variable Road maintenance Road/property damage risk under extreme heating 

degree days or cooling degree days

Determine stockpile or resources nedamage.

Safety and health risks, ice/snow removal operations affected, traveler delays

Road maintenance 

Dew Point Temperature (degrees F)

Decrease to less than 32o 

or increase to exceed 32o, 

with moisture

Air Temperature Relative to Freezing and Trend (degrees F and rising or falling trend)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Wet Bulb Temperature (degrees F)

Variable, based on temperature and impact criteria

Road maintenance Air temperature, fog dispersal effectiveness Predict threatened area, select treat

Disperse fog (cold fog) using CO2 ap

Relative Humidity (percent) Variable, 

based on impact criteria

Road maintenance Precipitation type, visibility restrictions Predict threatened area, select treat

 Variable, 

based on cargo humidity requirements 

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (Spacecraft, vehicles, and equipment must be maintained at specified humidity thresholds.)

Advise transport operators, ensure sconditioning equipment available to humidity requirements.

Road maintenance Air quality (Stable atmosphere inhibits dispersion of 

pollutants.) 

Modify operations. 

Atmospheric transport & diffusion & HAZMAT response

Health and safety risks, operational delays (Stable atmosphere inhibits dispersion of hazardous materials.)

Initiate HAZMAT (hazardous materiaand mitigation plan. Ensure proper notified.

Subsurface Temperature (degrees F)

Variable, based on other

contributing factors such as wind, shade, sun 

Road maintenance Pavement effects (Subsurface temperature affects 

pavement temperature, along with wind, insolation, shade, and other contributing factors.)

Predict threatened area, select treat

Loss of traction, safety risk to maintenance personnel and motorists, impacts on preventative treatment of roadways for ice (Some ice-preventative treatment operations can be completed in one shift; others require two shifts.)

Select treatment strategy, advise oppreparation procedures for applying liquid chemical tanks or hoppers for hours prior to time for applying treatm

Operational delays, increased workload, anti-icing and/or de-icing operations required

Treat/clear roadways with anti-icing, treatments. Adjust traffic flow manag

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Possible loss of control due to icy road surface. Reduce speed and exercise caution

Fleet utility and transport vehicle operations

Safety risk to operators, damage risk, schedule delays Advise operators, reschedule, rerout

Bus operations Safety risk to operators/passengers, schedule delays Advise operators, reschedule, reroutPrivate vehicles Safety risk to motorists, travel delays Advise motorists, reschedule, rerout

<32o with 

moisture <32o with moisture (observation and forecast)

Pavement Freeze Point Temperature with Dew Point Temperature (degrees F)

Road maintenance 

Stable/ unstable

Air Stability 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

State emergency management

Safety risk to motorists, hazardous cargo risks Advise operators, reschedule. 

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.Provide early warning, monitor equippersonnel for heat stress, modify maas required.Take prescribed health/safety and re

>90o Driveaway-towaway 

(manufactured home transport) 

Possible tire blow out on trailer Reduce speed and check tire pressu

>(15-18o) but 

<32o

Effects on snow/ice bonding and on snow removal/ice treatment operations, loss of traction

Predict threatened area, select treatPrepare, deploy and track treatment treatment chemicals/abrasives.

<15-18o Effects on snow/ice bonding and on snow removal/ice 

treatment operations, loss of traction, changes in treatment chemical effectiveness

Predict threatened area, select treatPrepare, deploy, and track treatmensnow, apply abrasives.

Pavement Temperature Variable, 

based on impact criteria

Road maintenance Effects on snow/ice bonding and snow removal/ice 

treatment operations, loss of traction, changes in treatment chemical effectiveness and snow/ice melting

Predict threatened area, select treatPrepare, deploy and track treatment apply treatment chemicals/abrasives

Wet Road maintenance Impaired mobility, loss of traction, loss of 

stability/maneuverability, safety risk

Predict threatened area, manage tra

Snow, snowpack

Road maintenance Impaired mobility, loss of traction, loss of 

stability/maneuverability, safety risk

Predict threatened area, select treatPrepare, deploy and track treatment treatment chemicals/abrasives, plow traffic flow.

Ice Road maintenance Impaired mobility, loss of traction, loss of 

stability/maneuverability, safety risk

Predict threatened area, select treatprepare, deploy and track treatment treatment chemicals/abrasives, man

Chemical Concentration (in-road sensor or mobile infrared)

Variable, based on application, residue

Road maintenance Safety risk, snow removal/ice treatment operations, 

snow/ice bonding

Select treatment strategy, deploy anassets. Apply treatment chemicals/aoutflow devices.

Provide early warning to operators aTake prescribed actions, advise opemaintenance personnel. Modify opeapplication of CO2 to disperse fog.

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Driveaway-towaway (manufactured home transport) 

Ability to see and be seen within safe reaction distance greatly reduced

Stop travel. 

Fleet utility and transport vehicle operations

Safety risk, schedule delays Advise operators, modify operations

Pavement Condition 

<1/4 mile

Road maintenance 

<1/4 to < 1/2 Road maintenance Safety risk, loss of visibility, impaired mobility

mile

Visibility, Including Restricting Conditions such as Fog, Haze, Dust, Smoke (statute miles) Pavement Temperature when Moisture is Present (degrees F)Pavement Temperature (degrees F)

Personnel health and safety, engine/equipment heat stress, pavement buckling

>85 Road maintenance o
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

NASA (Goddard) spacecraft and equipmenttransport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow moreroute (long haul) or delay movemecargo at air transport site and transpweather impacts 

Bus operations Safety risk, schedule delays Advise operators, modify operationsPrivate vehicles Safety risk, travel delays Advise motorists, modify travel. State emergency management

Transport risk to hazardous cargo Advise operators, modify operations

State police Increased workload due to hazardous travel conditions Advise operators, modify operationsRoad maintenance Restricted visibility in glare quadrant of horizon Advise operators and maintenance p

speed.

Truck operations Restricted visibility in glare quadrant of horizon, safety 

risk to operators, freight/cargo damage risk, schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators, reduce speed. 

Fleet utility and transport vehicle operations

Restricted visibility in glare quadrant of horizon Advise operators, reduce speed. 

NASA (Goddard) spacecraft and equipment

transport

Restricted visibility in glare quadrant of horizon, safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment)

Advise transport operators, slow mo

Bus operations Restricted visibility in glare quadrant of horizon Advise operators, reduce speed. Private vehicles Restricted visibility in glare quadrant of horizon Advise motorists, reduce speed. State emergency management

Restricted visibility in glare quadrant of horizon Advise operators, reduce speed. 

State police Restricted visibility in glare quadrant of horizon Advise operators, reduce speed. 

Predict threatened area, advise travtreatment strategy, implement early procedures. Consider implementatioplans. Construct and place living and fences to manage snow drifting.Modify operations, prepare for snow Manage traffic flow (restrict access tbridges, restrict access to specific veremove debris, repair damage. 

>30 and <50 mph

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

>25 mph and gusty

Driveaway-towaway (manufactured home transport) 

Difficult handling of trailer and load (manufactured home or section)

Stop travel. 

>30 and <50 mph

Fleet utility and transport vehicle operations

Safety risk to operators Advise operators, modify operations

Sun Glare

Safety risk to personnel and motorists, increased roadway and lane obstruction (debris), reduced or lost visibility, drifting snow, loss of stability and maneuverability, road damage, loss of life or property, treatment chemical dispersion, loss of communications and power, toxicity and environmental damage (Speed and direction are most important when snow has accumulated.)

>30 and <50 Road maintenance mph

Wind: Head, Cross, or Tail (wind speed in miles per hour)

Any
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

>30 mph NASA (Goddard) 

spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators, slow moreroute (long haul) or delay movemecargo at air transport site and transpweather impacts 

>30 and <50 mph

Bus operations Increased safety risk, roadway debris, flying debris, 

traffic congestion, downed live electric lines and or poles, increased risk of damage to busses and property, schedule delays

Advise operators, plan route detourswatches issued, modify, restrict, or sNotify passengers (public address sy

>30 and <50 mph

Private vehicles Safety risk to operators/passengers Advise motorists, modify travel. 

>30 and <50 mph

State emergency management

Transport risk to hazardous cargo Advise operators, modify operations

>30 and <50 mph

State police Increased workload due to hazardous travel conditions Advise operators, modify operations

>35 mph and sustained

Power generating operations

Line damage, transmission impairment or loss Alert managers, dispatch line repair 

needed.Predict threatened area, advise travtreatment strategy, implement early procedures. Review and consider imevacuation plans. Construct and plastructural snow fences to manage snModify operations, implement snow traffic flow (restrict access to roadwarestrict access to specific vehicle typ

repair damage. 

Truck operations Safety risk to operators, freight/cargo damage risk, 

schedule delays, increased risk of collisions/spills of hazardous cargo

Advise operators and managers, conassessment. Delay, postpone, reschappropriate. If underway, especially hazardous materials, find a safe stop

Fleet utility and transport vehicle operations

Safety risk to operators Advise operators, reschedule, rerout

Bus operations Increased safety risk, roadway debris, flying debris, 

traffic congestion, downed live electric lines and or poles, increased risk of damage to busses and property, schedule delays, detours required on routes

Advise operators, plan route detourswatches issued, modify, restrict, or sNotify passengers (public address sy

Private vehicles Safety risk to operators/passengers Advise motorists, reschedule, reroutState emergency management

Transport risk to hazardous cargo Advise operators, plan route detours

watches issued, modify, restrict, or sNotify passengers (public address sy

State police Increased workload due to hazardous travel conditions Advise operators, reschedule, adjus

management.Move in emergency equipment to cleperform timber salvage operations.Determine where downed timber anmay have occurred in remote areas on visual observations and field repousing weather radar, etc.

Wind: Head, Cross, or Tail >50 mph(wind speed in miles per hour)

Access roads blocked by debris and falled timber, valuable timber blown down/damaged (Downed timber

requires timely salvage before its value is lost.)

U.S. Forest ServiceRoad maintenance Safety risk to personnel and motorists, increased 

roadway and lane obstruction (debris), reduced or lost visibility, impaired mobility, drifting snow, loss of stability and maneuverability, road damage, loss of life or property, treatment chemical dispersion, loss of communications and power, toxicity and environmental damage (Speed and direction are most important when snow has accumulated.)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Surface Wind Direction Any speed Road maintenance Drifting snow, wild fire tracking, toxicity and 

environmental damage

Predict threatened area, select treatRemove debris, repair damage.

Upper Air Winds Standard 

levels

Road maintenance Air quality, storm cell tracking, toxicity and 

environmental damage

Predict threatened area, select treatRemove debris, repair damage.Provide early warning. Advise maintenance personnel, canoperations.

Truck operations Safety risks (hypothermia, frost bite) Advise operators, modify operationsDriveaway-towaway (manufactured home transport) 

Safety risks for drivers (hypothermia, frost bite) Advise operators and minimize outs

Fleet utility and transport vehicle operations

Safety risks (hypothermia, frost bite) Advise operators, modify operations 

NASA (Goddard) spacecraft and equipment

transport

Safety risks (hypothermia, frost bite) Advise operators, delay operations. 

Bus operations Safety risks (hypothermia, frost bite) Advise operators, modify operationsPrivate vehicles Safety risks (hypothermia, frost bite) Advise motorists, modify travel. State emergency management

Safety risks (hypothermia, frost bite) Advise operators, modify operations

State police Safety risks (hypothermia, frost bite) Advise operators, modify operations

Provide early warning. Advise operators, modify/restrict ope

Truck operations Personnel heat exhaustion Advise operators, modify/restrict opeDriveaway-towaway (manufactured home transport) 

Safety risk for driver (heat exhaustion) Advise operator, have water availab

Fleet utility and transport vehicle operations

 Personnel heat exhaustion Advise operators, modify/restrict ope

NASA (Goddard) spacecraft and equipmenttransport

 Personnel heat exhaustion Advise operators, modify/restrict ope

Bus operations Personnel heat exhaustion Advise operators, modify/restrict opePrivate vehicles Personnel heat exhaustion Advise motorists, modify/restrict travState emergency management

 Personnel heat exhaustion Advise operators, modify/restrict ope

State police Personnel heat exhaustion Advise operators, modify/restrict ope

variable extremes based on impact criteria

Power generating operations

Existing and anticipated power loads and transmissioncapacities altered by temperature extremes

Adjust marketing strategies to ensurtransmissions. Advise managers, aleline repair personnel.Provide early warning, advise operaoperations in urban areas.Modify operations in urban areas. 

<32o

<20o> 105o

Air Quality Potential health and safety risks, operational delays Code orange Road maintenance 

or red

Wind Chill (degrees F) 

Heat Index (degrees F) Road maintenance Personnel heat exhaustion

Road maintenance Safety risks (hypothermia, frost bite)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Truck operations Potential health and safety risks, operational delays Advise operators, modify operations Fleet utility and transport vehicle operations

Potential health and safety risks, operational delays Advise operators, modify operations 

Bus operations Potential health and safety risks, operational delays Advise operators, modify operations Private vehicles Potential health and safety risks, operational delays Advise motorists, modify travel in urbState emergency management

Potential health and safety risks, operational delays Advise operators. 

State police Potential health and safety risks, operational delays Advise operators. Atmospheric Transport and Diffusion and HAZMAT response

Potential health and safety risks, operational delays Initiate HAZMAT spill reaction and m

Ensure proper authorities are notifie

Road maintenance Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

Truck operations Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

Fleet utility and transport vehicle operations

Possible loss of communications, power, GPS navigation

Advise operators, monitor communic

NASA (Goddard) spacecraft and equipment

transport

Possible loss of communications, power, GPS navigation

Advise operators, monitor communic

Bus operations Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

Private vehicles Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

State emergency management

Possible loss of communications, power, GPS navigation

Advise operators, monitor communic

State police Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

U.S. Forest Service Possible loss of communications, power, GPS 

navigation

Advise operators, monitor communic

Total Sun (insolation hours per day)

All Road maintenance Air temperature, pavement temperature, toxicity, and 

environmental damage 

Modify operations as necessary. 

Cloud Cover Forecast Scattered, 

broken, overcast

Road maintenance Air temperature, pavement temperature, toxicity, and 

environmental damage 

Modify operations as necessary. 

Road maintenance Flood risk, lane submersion, loss of life and property, 

road damage

Predict threatened area, select treatoperate outflow devices, develop waevacuation plans.

U.S. Forest Service Flood risk, road submersion, loss of life and property, 

road damage

Predict threatened area, operate outdevelop warning and evacuation pla

Variable, based on floodstage criteria

Water Course Flow Volume (cubic meters per second)Space Weather (solar flares, etc.)

Any
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

State emergency management

Transport risk to hazardous cargo Advise operators. 

Road maintenance Flood risk, lane submersion, loss of life and property, 

road damage

Predict threatened area, select treatoperate outflow devices, develop waevacuation plans.

U.S. Forest Service Flood risk, road submersion, loss of life and property, 

road damage

Predict threatened area, operate outdevelop warning and evacuation pla

State emergency management

Transport risk to hazardous cargo Advise operators. 

Road maintenance Safety risk, damage to vehicles, road damage, 

evacuation route delays

Predict threatened area, repair dama

Truck operations Safety risk, damage to vehicles, road damage, 

evacuation route delays

Advise operators. Reroute or suspen

Fleet utility and transport vehicle operations

Safety risk, damage to vehicles, road damage, evacuation route delays

Advise operators. Reroute or suspen

NASA (Goddard) spacecraft and equipment

transport

Safety risk, damage to vehicles, road damage, evacuation route delays

Advise operators. Reroute or delay t

Bus operations Increased safety risk, damage to busses, delays to 

scheduled operations, complete disruption of service for busses that travel coastal roads 

Advise operators and road supervisoconditions. Modify, restrict, or suspeRequest radio reports of observed sthe highway.

Private vehicles Safety risk, damage to vehicles, road damage, 

evacuation route delays

Advise motorists. Reroute, restrict, o

State emergency management

Safety risk, damage to vehicles, road damage, evacuation route delays

Implement emergency response proappropriate.

State police Safety risk, damage to vehicles, road damage, 

evacuation route delays

Implement emergency response proappropriate.

U.S. Forest Service Potential safety risks, stranded recreationists Advise field personnel and recreatio

Variable, based on floodstage criteria

Water Body Depth (feet)Hurricane Storm Surge Any
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

High Surf (wave height in feet)

>8 feet Road maintenance Safety risk, damage to vehicles, road damage, 

evacuation route delays

Predict threatened area, repair dama

Road maintenance Impaired mobility, loss of life and property, lane 

obstruction, effects on snow removal/ice treatment operations

Close roadways, release avalanche, modify operations as necessary.

U.S. Forest Service Life threat, safety risk to recreationalists, Forest 

Service workers

Pass warnings to forest users, worke

Road maintenance Road/property damage risk, impaired mobility, loss of 

life and property

Manage traffic flow, modify operationrepair damage.

U.S. Forest Service Life threat, safety risk to recreationalists, Forest 

Service workers

Pass warnings to forest users, worke

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft/vehicles/equipment), transport schedule delays, potential launch schedule delays

Advise transport operators. Reroute movement.

Road maintenance Road/property damage risk, impaired mobility, loss of 

life and property, air quality

Manage traffic flow, modify operation

U.S. Forest Service Cataclysmic devastation of large areas (Mt. St. Helens 

National Monument is administered by the Forest Service. Many dormant volcanos are on National Forest land: Shasta, Medicine Lake, Three Sisters, MtHood, etc.)

Issue warnings and advisories. Implrescue or evacuation plans, as nece

NASA (Goddard) spacecraft and equipment

transport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators. Reroute movement. 

Soil Moisture Saturated, 

unsaturated

Road maintenance Flood risk, road/pavement damage, pavement 

condition

Select treatment strategy, select roa

Road maintenance Loss of visibility, loss of life and property, air quality Manage traffic flow (close roadways

U.S. Forest Service Life threat, safety risk Conduct fire fighting operations. 

Seismic Activity Volcanism Fire Avalanche Danger High, 

moderate, lowAny seismic activityAny volcanic activityAny fire event or activity
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

NASA (Goddard) spacecraft and equipmenttransport

Safety risk to transport vehicle operators, damage risk to unique cargo (spacecraft, vehicles, equipment), transport schedule delays, potential launch schedule delays

Advise transport operators. Reroute movement.

1 to 10 days Road maintenance Operational planning (The tasks that will be 

undertaken in periods of good weather depend somewhat on how much good weather is anticipated. Crews work year round; there are no reserves or parttime personnel to call in for snow or other severe weather events. Details of crew assignments vary day to day, some days plowing and sanding, some days working on drainage, some days on signs and guardrail, etc. A certain amount of mobilization is required for some tasks.)

Examples: (1) Ditching requires remmounting a truck box, and replacing attachment on a loader with a bucke

probably take 2 days. Such actions cwithout a forecast of 10 days of good weather because of the time needed equipment. (2) In urban areas, snow necessary following a storm. The sais needed to clean up after a 6-inch one. If good weather is forecast folloevent, hauling might be started. If anforecast within several days, hauling (3) Forecasts of good weather, as wmanagers in deploying crews efficie

Truck operations Risks to weather sensitive operations, cargo, or time 

constraints

Carry out operations and travel/transbased on forecast of fair weather for 

Fleet utility and transport vehicle operations

Risks to weather sensitive operations, cargo, or time constraints

Carry out operations and travel/transbased on forecast of fair weather for 

NASA (Goddard) spacecraft and equipment

transport

Risks to weather sensitive operations, cargo with unique weather parameter requirements, or travel timerequirements

Carry out operations and travel/transbased on forecast of fair weather for 

Bus operations Risks to weather sensitive operations or time 

constraints

Carry out operations and travel/transbased on forecast of fair weather for 

Private vehicles Risks to weather sensitive travel or travel time 

requirements

Carry out operations and travel/transbased on forecast of fair weather for 

State emergency management

Risks to weather sensitive operations, cargo with unique weather parameter requirements, or travel time

requirements

Carry out operations and travel/transbased on forecast of fair weather for 

State police Risks to weather sensitive operations or time 

requirements

Carry out operations and travel/transbased on forecast of fair weather for 

1 to 10 days of

mean temperatures >50-60o F

U.S. Forest Service Risks to seal coating operations (Resurfacing of roads 

with road oil and gravel to seal road cracks is often done during the fall. Seal coating fails if temperatures fall below 50-60o F during resurfacing.)

Carry out operations and travel/transbased on forecast of fair weather for 

Road maintenance Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Close or detour roadways. Assist in Transport and Diffusion and HAZMAoperations as needed.

Truck operations Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

Fleet Utility and Transport

Vehicle Operations

Severe threat to life, health and safety risks from dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

Nuclear, Biological, or Chemical Release Fair Weather (duration in days)

Variable, based on impact criteriaAny
Weather Element Threshold Activity Impacts Action 

Weather Needs for Roadway Transportation

Fleet utility and transport vehicle operations

Severe threat to life, health and safety risks from dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

NASA (Goddard) spacecraft and equipment

transport

Severe threat to life, health and safety risks from dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

Bus operations Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

Private vehicles Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Cease transport operations/travel or 

State emergency management

Severe threat to life, health and safety risks from dispersion of extremely dangerous hazardous materials, agents, substances

Close or detour roadways. ImplemenTransport and Diffusion and HAZMAoperations as needed.

State police Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Close or detour roadways. Assist in Transport and Diffusion and HAZMAoperations as needed.

U.S. Forest Service Severe threat to life, health and safety risks from 

dispersion of extremely dangerous hazardous materials, agents, substances

Close or detour roadways. Assist in Transport and Diffusion and HAZMAoperations as needed.
Weather Information for Surface Transportation

Appendix B–1.1

Federal Highways WIST Needs Template
Weather Information for Surface Transportation

Federal Highway Activities

(Same as Roadway Sector Activities in Appendix B-1)

Road maintenance. This activity is generally where the requirements of the state transportation departments are

compiled. It includes road surface treatment for snow and ice control in the winter, as well as road and

infrastructure maintenance year-round to repair damage.

Truck operations. The primary example for this activity is commercial trucking operations, both local and long

haul.

Fleet utility and transport vehicle operations. This activity includes small to medium size fleets of utility

vehicles, such as those maintained by telephone or cable television companies, as well as the large, nationwide

fleets of mail and parcel delivery vehicles.

Bus operations. This activity is intended to cover primarily long-haul bus operations, such as interstate travel,

rather than school buses or local transit system buses, both of which are covered by the Rural and Urban Transit

Operations sector.

Private vehicle operations. Private vehicle operators, daily commuters, long-distance travelers, and local drivers,

as well as rental car operators, are included in this activity.

State/local emergency managers. This activity encompasses emergency managers at state and local levels.

State police. Although state police and highway patrol entities provided the input on WIST needs for this activity,

the information is generally valid for law enforcement and public safety officials anywhere with roadway traffic

safety responsibilities.

Forest Service. The roadway operations of the U.S. Forest Service role are limited to unimproved roads under its

jurisdiction within national forests and grasslands. But the ways in which the weather affects these roads has

major impact on all the uses of these areas.

Special Groups

NASA spacecraft and equipment transport. NASA’s principal concern with roadways is in transporting

spacecraft and components by land routes between its various centers and the launch facilities.

Power generating operations. The WIST needs of the power marketing associations (see Section 3.1.2) are

limited to road conditions that affect the ability of repair crews in utility vehicles to reach transmission

lines and facilities.

Manufactured home transport. This specialized activity has WIST needs that represent the general class of

high-profile vehicles, which have special sensitivities to wind and other weather elements, such as those

that affect tire traction.
Weather Element Threshold Forecast/Observation Impacts Action 

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, loss of communications/power, slope instability (avalanche risk), operational delays (increased workload)

Predict threatened area, select treoperators, begin preparation procePrepare, deploy and track treatmetreatment chemicals/abrasives. Madisseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, implerestrict access to designated vehicdebris, repair damage.

Structure Ice Accumulation (inches)

Any Observation Loss of communications/power, property and structural 

damage, safety risk 

Predict threatened area, select treRemove debris, repair damage.

Pavement Ice Accumulation (inches)

Any Observation Safety risk, impaired mobility, loss of stability/ 

maneuverability, loss of traction, pavement damage, pavement temperature, effects on snow removal/ice treatment operations

Predict threatened area, select treRemove debris, repair damage.

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Predict threatened area, select treoperators. Begin preparation procecrew planning, shift changes, geogand deployment. 

Operational delays (increased workload) Prepare, deploy, and track treatme

apply treatment chemicals/abrasiv(e.g., disseminate traveler informamodify lane configuration, modify smetering, close roadways and bridcontrols, restrict access to designa

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Predict threatened area, select treoperators. Disseminate warning in(press releases, dynamic message highway advisory radio, transmitteBegin preparation procedures for eplanning, shift changes, geographdeployment. 

 Prepare, deploy, and track treatme

apply treatment chemicals/abrasiv(e.g., disseminate traveler informamodify lane configuration, modify smetering, close roadways and bridcontrols, restrict access to designa

Frozen Precipitation (snow, inches)

>2 to <8 inches Forecast

Any to <2 inches Forecast

Weather Needs for Federal Highway Operations

Freezing Precipitation (ice) Any Forecast
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Advise operators. Disseminate watravelers (press releases, dynamic roadside highway advisory radio, tInternet, etc.). Begin preparation pequipment, crew planning, shift chreassignment and deployment.Plow snow, apply treatment chemiimplement tire chain control operaand track treatment assets. Managdisseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, restridesignated vehicle types).

Any to <8 inches Safety risk to maintenance personnel and motorists, 

travel delays, impaired plowing, lane obstruction, loss of

visibility, loss of traction, impaired mobility, effects on snow removal/ice treatment operations (Winds greater than 15 mph can lead to blowing snow and drifting in some areas. The amount of snow already on the groundmay not be the determining factor. If snow storage areasare full, even a few inches can cause drifting problems. Drifting snow requires continuous and prolonged clearing operations, which strains manpower resources.)

Predict threatened area, select treconsider road closures. Disseminato travelers (press releases, dynamroadside highway advisory radio, tInternet, etc.). Begin preparation pequipment, crew planning, shift chreassignment and deployment. Coliving and structural snow fences. Select treatment strategy. Preparetreatment assets, Manage snow reoperations (plow snow, treat/clear traffic flow (e.g., disseminate travespeed limit, modify lane configurattiming/ramp metering, close roadwimplement tire chain controls, restrdesignated vehicle types).

Snow Accumulation (inches) Any Observation Drifting snow, impaired mobility, impaired plowing, lane 

obstruction, loss of stability and maneuverability, loss of traction, pavement temperature effects, slope instability (avalanche risk)

Prepare, deploy, and track treatmeapply treatment chemicals/abrasivrepair damage. Manage traffic flow traveler information, vary speed limconfiguration, modify signal timing/roadways and bridges, implement access to designated vehicle types

Snow Drift Levels (inches) Any Observation Impaired plowing, lane obstruction Predict threatened area, select tre

Roadway Snow Depth (inches) Any Observation Loss of traction, impaired mobility, effects on snow 

removal/ice treatment operations

Select treatment strategy. 

Roadway Snow Pack Depth (inches)

Any Observation Loss of traction, impaired mobility, effects on snow 

removal/ice treatment operations

Select treatment strategy. 

Drifting Snow (inches)

> 8 inches

Forecast

> 8 inches Forecast
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Adjacent Snow Depth (inches) Any Observation Drifting snow, roadway snow depth Select treatment strategy. Snow/Ice Bonding (inches) Any Observation Effects on snow removal/ice treatment operations Select treatment strategy. 

Predict threatened area, advise opwarning information to travelers. Sprocedures and planning activitiesManage traffic flow, operate outflow drainage, finalize decisions.

Precipitable Water Vapor (inches) 

Any Observation 

(by satellite imagery interpretation)

Precipitation patterns and rates Predict threatened area, select tre

Safety risks, road submersion, loss of life and property, road damage, bridge damage, travel delays

Begin preparation procedures, plaReview/revise contingency plans,  Disseminate warning information local mobilization, response action(close roadways and bridges), predrainage.

Thunderstorms with Lightning (proximity to route or operational area in miles)

< 5 miles Forecast and observation Safety risks, loss of life, property damage, loss of 

communications/power, operational delays

Predict threatened area, advise oprefueling, restrict/suspend operatio

Any size, <5 miles

Forecast and observation Safety risk to maintenance personnel and motorists, 

travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life, property damage, loss of communications/power, operational delays

Predict threatened area, advise oprefueling, restrict/suspend operatio(e.g., disseminate traveler informamodify lane configuration, modify smetering, close roadways and bridcontrols, restrict access to designa

>1/4 inch, <5 miles

Forecast and observation 

<10 miles Forecast and observation Loss of visibility, loss of traction, impaired mobility, lane 

obstruction/submersion, loss of life, property damage, loss of communications/power 

Predict threatened area, select tredevelop warning and evacuation pmaintenance forces.

<5 miles Forecast and observation Loss of visibility, loss of traction, impaired mobility, lane 

obstruction/submersion, loss of life, property damage, loss of communications/power 

Issue evacuation orders. Manage disseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, implerestrict access to designated vehicoutflow devices, remove debris, re

Liquid Precipitation (inches) Any Forecast

Forecast

Thunderstorms with Hail (hail size, proximity to route or operational area in miles)Thunderstorms with Tornado or Waterspout (proximity to route or operational area in miles)Flooding Any

Impaired mobility, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction/ submersion, road damage, treatment chemical dispersion, toxicity and environmental damage, slope instability (landslide risk)
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Severe Storm Cell Track—Location, Direction, Speed, Severity (proximity to route or operational area in miles, basedon radar observation)

<20 miles Forecast and observation Credibility of evacuation orders, loss of visibility, loss of 

traction, impaired mobility, lane obstruction/submersion,loss of life, property damage, loss of communications/ power, flood risk, road damage 

Predict threatened area, develop wplans, issue evacuation orders, seMobilize maintenance personnel. (e.g., disseminate traveler informamodify lane configuration, modify smetering, close roadways and bridcontrols, restrict access to designaOperate outflow devices, remove d

Major StormsBlizzard—35 mph Sustained Winds, Visibility <1/4 mile, Blowing Snow (proximity to route or operational area in miles)

<50 miles Forecast and observation Safety risks, loss of life, property damage, road 

damage, loss of visibility, loss of traction, impaired mobility, evacuation route delays, lane obstruction, loss of communications/power 

Predict threatened area, disseminato operators and travelers, select tSuspend outdoor operations, impleplans, mobilize maintenance force

Hurricane Force Winds (wind speed in mph and proximity to route or operational area in miles)

>74 mph, 

<50 miles

Forecast and observation Safety risks, loss of life, loss of visibility, loss of traction, 

impaired mobility, evacuation route delays, lane obstruction/submersion, loss of communications/power, property damage, road damage 

Predict threatened area, disseminato operators and travelers. Suspenimplement evacuation plans, mobiforces, repair damage.

Tropical Storm Force Winds (wind speed in mph and proximity to route or operational area in miles)

>39 mph but <74 

mph, <50 miles

Forecast and observation Safety risk, potential loss of life, loss of visibility, loss of 

traction, impaired mobility, evacuation route delays, lane obstruction/submersion, loss of communications/ power, property damage, road damage

Predict threatened area, disseminato operators and travelers. Suspenimplement evacuation plans, mobiforces, repair damage.

Hurricane Storm Surge Any Forecast and observation Safety risks, flood risk, loss of life, loss of traction, 

impaired mobility, evacuation route delays, lane obstruction/submersion, loss of communications/power, property damage, road damage

Predict threatened area, disseminato operators and travelers. Suspenimplement evacuation plans, mobiforces, repair damage.

General Weather/Environmental ParametersAir Temperature including Maximum and Minimum (degrees F)

Variable, based on impact criteria

Forecast and observation Air quality, loss of communications/power, precipitation 

type, pavement temperature, slope stability (avalanche risk), effects on snow removal/ice treatment operations

Advise operators, monitor surface operations.

Air Temperature Relative to Freezing and Trend (degrees F and rising or falling trend)

Decrease to less than 32o or 

increase to exceed 32o, with moisture

Forecast Precipitation type, pavement temperature, loss of 

communications/power, slope instability (avalanche risk), effects on snow removal/ice treatment operations, road damage

Disseminate early warning informaoperators, monitor surface moistur

>85o Forecast Health and safety risks, engine/equipment heat stress Advise operators, monitor personn

stress, take prescribed and precau

>110o Forecast Severe and immediate health and safety danger to 

personnel and heat stress risk to equipment 

Conduct immediate risk assesmen

supervisors to ensure continuous mand equipment. Cease activities. 

Dew Point Temperature (degrees F)

Variable, based on temperature and impact criteria

Forecast and observation Air quality, precipitation type, fog formation Predict threatened area, select tre

Air Temperature 

(degrees F) 
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Air Temperature Change Rate (degrees F per 24 hours)

Approx. 60o in 24 

hours

Forecast and observation Precipitation type, pavement temperature, road damage 

(pavement buckling damage due to rapid expansion and contraction)

Predict threatened area, select tredamage.

Time and Air Tempeerature Integrals (heating/cooling degree days)

24 hour Forecast and observation Road damage, property damage (risk under extreme 

heating degree days or cooling degree days)

Determine stockpile or needed res

Wet Bulb Temperature (degrees F)

Variable, based on temperature and impact criteria

Forecast and observation Air temperature, fog dispersal effectiveness Predict threatened area, select tre

disperse fog (cold fog).

Relative Humidity (percent) Variable, based 

on impact criteria

Forecast and observation Precipitation type, loss of visibililty Predict threatened area, select tre

Air Stabililty Stable/unstable Forecast and observation Air quality (Stable atmosphere inhibits dispersion of 

pollutants.)

Modify operations, manage traffic Disseminate warning information ttravelers, modify operations in urbModify operations. 

Subsurface Temperature (degrees F)

Variable, based on contributing factors such as wind, shade, sun

Forecast and observation Pavement temperature Predict threatened area, select tre

Disseminate early warning informamonitor equipment/personnel heaoperations.Take prescribed health/safety and 

Pavement Freeze Point Temperature with Dew Point Temperature (degrees F)

<32o with 

moisture (observation and forecast)

Forecast and observation Loss of traction, safety risk to operations personnel and 

motorists, effects on snow/ice removal operations. (Some treatment operations can be completed in one shift, others require two shifts.)

Select treatment strategy, advise opreparation procedures. At 12 houroadway treatment start time, prepequipment for application (e.g., fill or hoppers for salt application).

>15-18o but 

<32o

Forecast Impaired mobility, snow/ice bonding, effects on snow 

removal/ice treatment operations, loss of traction

Predict threatened area, select trePrepare, deploy, and track treatmetreatment chemicals/abrasives.

<15-18o Forecast Impaired mobility, snow/ice bonding, effects on snow 

removal/ice treatment operations, loss of traction, effects

on treatment chemical effectiveness

Predict threatened area, select trePrepare, deploy, and track treatmeapply abrasives.

Variable, based on impact criteria

Observation Impaired mobility, snow/ice bonding, effects on snow 

removal/ice treatment operations, loss of traction, effects

on treatment chemical effectiveness, melting

Predict threatened area, select trePrepare, deploy, and track treatmeapply treatment chemicals/abrasiv

Air Quality Code orange or Health and safety risk, operational delays

red>85-90o

Pavement Temperature (degrees F) Pavement Temperature (degrees F)

Forecast Health and safety risks, engine/equipment heat stress, 

pavement "blow-ups" (Subsurface temperature affects pavement temperature, but other factors such as wind, insolation, and shade also contribute.) 

Forecast
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Wet Forecast and observation Safety risks, impaired mobility, loss of traction, loss of 

stability/maneuverability

Predict threatened area. Manage tdisseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, implerestrict access to designated vehic

Snow/slush Forecast and observation Safety risks, impaired mobility, loss of traction, loss of 

stability/maneuverability

Predict threatened area, select trePrepare, deploy, and track treatmeManage traffic flow (e.g., dissemininformation, vary speed limit, modimodify signal timing/ramp meteringbridges, implement tire controls, redesignated vehicle types).

Ice Forecast and observation Safety risks, impaired mobility, loss of traction, loss of 

stability/maneuverability

Predict threatened area, select trePrepare, deploy, and track treatmetreatment chemicals/abrasives. Madisseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, implerestrict access to designated vehic

Chemical Concentration Variable, based 

on application, residue

Observation (sensor or mobile infrared) 

Safety risks, effects on snow removal/ice treatment operations, snow/ice bonding

Select treatment strategy, apply trechemicals/abrasives, deploy and t

Visibility (statute miles)

<1/4-1/2 mile Forecast and observation Safety risk, loss of visibility (due to fog, haze, dust, 

smoke), impaired mobility

Disseminate warning information ttravelers, modify operations, consioptions (e.g., CO2 application).

Glare Any Forecast and observation Loss of visibility in glare quadrant of horizon Advise operators, modify operation

>30 mph but <50 mph 

Forecast Safety risk, drifting snow, loss of visibility, loss of 

stability/maneuverability, lane obstruction (debris), road damage, loss of life and property, treatment chemical dispersion, loss of communications/power, toxicity and environmental damage, pavement temperature

Predict threatened area, modify optreatment strategy, develop warninplans. Remove debris, repair damaflow (e.g., disseminate traveler infolimit, modify lane configuration, motiming/ramp metering, close roadwimplement tire controls, restrict accvehicle types). 

>50 mph Forecast Safety risk, drifting snow, loss of visibility, loss of 

stability/maneuverability, impaired mobility, lane obstruction (debris), road damage, loss of life and property, treatment chemical dispersion, loss of communications/power, toxicity and environmental damage, pavement temperature

Predict threatened area, select trerestrict/suspend operations, develoevacuation plans. Remove debris, Manage traffic flow (e.g., dissemininformation, vary speed limit, modimodify signal timing/ramp meteringbridges, implement tire controls, redesignated vehicle types). 

Surface Wind Direction Any speed Forecast and observation Drifting snow, wild fire tracking, toxicity and 

environmental damage, pavement temperature

Predict threatened area, select treRemove debris, repair damage.

Pavement ConditionWind: Head, Cross, Tail (speed in miles per hour)
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Upper Air Winds Standard levels Forecast Air quality, storm cell tracking, toxicity and 

environmental damage, air stability

Predict threatened area, select treRemove debris, repair damage.

High Winds Variable, based 

on impact criteria

Observation Safety risk, drifting snow, loss of visibility, loss of 

stability/maneuverability, impaired mobility, lane obstruction (debris), road damage, loss of life and property, treatment chemical dispersion, loss of communications/power, toxicity and environmental damage

Predict threatened area, select treoperations, develop warning and eRemove debris, repair damage. Mdisseminate traveler information, vlane configuration, modify signal ticlose roadways and bridges, implerestrict access to designated vehic

Wind Chill (degrees F) <20o to 32o Forecast and observation Safety risk (hypothermia, frost bite) Advise operators, restrict or suspe

Disseminate warning information ttravelers. Advise operators, modify/restrict o

Space Weather (solar flares, etc.)

Any Forecast and observation Loss of communications/power, impaired GPS 

location/navigation

Advise operators, monitor commun

Total Sun (insolation) Total hours Forecast and observation Air temperature, pavement temperature, toxicity and 

environmental damage, air quality 

Modify operations. 

Cloud Cover Scattered, 

broken, overcast

Forecast and observation Air temperature, pavement temperature, toxicity and 

environmental damage 

Modify operations. 

Water Course Flow Volume (cubic meters per second)

Variable, based on flood stage criteria

Forecast and observation Flood risk, lane submersion, loss of life and property, 

road damage

Predict threatened area, select tredevelop warning and evacuation pdevices.

Water Body Depth (feet) Variable, based 

on flood stage criteria

Forecast and observation Flood risk, lane submersion, loss of life and property, 

road damage

Predict threatened area, select tredevelop warning and evacuation pdevices.

High Surf (wave height in feet) >8 feet Forecast and observation Safety risk, property damage, road damage, evacuation 

route delays

Predict threatened area, disseminato operators and travelers. Repair 

Avalanche Danger High, moderate, 

low

Forecast and observation Impaired mobility, loss of life and property, lane 

obstruction, effects on snow removal/ice treatment operations

Manage traffic flow (close roadwayrelease avalanche, remove snow.

Seismic Activity Any seismic 

activity

Forecast and observation Road damage, property damage, impaired mobility, loss

of life and property

Manage traffic flow, modify operatrepair damage.

Heat Index (degrees F) >105o Forecast Health and safety risk (heat exhaustion)
Weather Element Threshold Forecast/Observation Impacts Action 

Weather Needs for Federal Highway Operations

Volcanism Any volcanic 

activity

Forecast and observation Road damage, property damage, impaired mobility, loss

of life and property, air quality

Manage traffic flow, modify operat

Soil moisture Saturated, 

unsaturated

Forecast and observation Flood risk, road/pavement damage, pavement condition Select treatment strategy. 

Fire Any fire event or 

activity

Forecast and observation Loss of visibility, loss of life and property, air quality Manage traffic flow (e.g., dissemin

information, vary speed limit, modimodify signal timing/ramp meteringbridges, implement tire controls, redesignated vehicle types).

Fair Weather 1 to 10 days 

(variable, based on impact criteria)

Forecast Operations planning (Forecasts of good or bad weather 

aid managers in deploying raod crews efficiently on short and long term weather-sensitive operations with specific time constraints. Crews work year round with no reserve personnel, and mobilization is required for some tasks. Work details vary day to day; undertaking tasks that require good weather depends on how much good weather is anticipated.)

Modify operations. Examples: (1) Dremoving the sanders, mounting a replacing the blower attachment obucket. These jobs would probably actions cannot be started without a good (non-snow) weather because reconvert the equipment. (2) In urbhauling is necessary following a st

of work is needed to clean up after inch one. If good weather is forecaevent, hauling might be started. If forecast within several days, haulin

Nuclear, Biological, or Chemical Release 

Any Forecast and observation Health and safety risk (potential severe threat to life), 

dispersion of hazardous materials

Close/detour roadways. Assist in Aand Diffusion and HAZMAT respon
Weather Information for Surface Transportation

Appendix B - 2

Long Haul Rail
Weather Information for Surface Transportation

Long-Haul Railway Activities

Railway/control center operations. The control center monitors the railroad system and advises train and

station operators and dispatchers. It controls system integrity.

Station and depot operations. Operations at and in the vicinity of stations, involving tracks, rolling stock, and

platforms.

Hump yard operations. Includes maintenance, inspections, and local operations.

Construction. Includes scheduling, maintenance, and repair activities.

Hazardous material. Includes monitoring the transport and handling of materials, as well as mitigation,

reclamation, and reporting of events or incidents.

Surveillance. Includes inspections, monitoring, and maintenance of trackage, supporting structure, and facilities.

Personnel safety. Safety of train crews, station and depot personnel, and passengers.
Weather Element Threshold Activity Impacts Action 

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing ice off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, possible malfunction of track sensors and signal sensors, possible signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.) 

Advise and update dispatch centers, creaffected areas, review and prepare treaice/snow plan, choose applicable chemiModify operations to forecast conditionsfeasible, plan for slowing or stopping, codepartures. Inspect tracks, repair as necadvisories and updates regarding weathconditions. Prepare to initiate crew reca

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing ice off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, possible malfunction of track sensors and signal sensors, possible signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.), increased attention to hazardous material (monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, prepare treatment optionice/snow plan, apply chemical treatmenoperations for conditions. Slow or stop tdelay departure from station. Inspect traPublish and distribute advisories and upsituation and track conditions. Initiate crnotification. If HAZMAT incident occurs, reaction/mitigation plan.

Frozen Precipitation (snow, inches)

Any Reduced ability of employees to get to work, impeded/restricted foot traffic and 

road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, possible malfunction of track sensors and signal sensors, possible signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.)

Advise, warn, and update dispatch centPredict affected areas, review and prepinitiate ice/snow plan, apply chemical treModify operations for current or forecastrains, reroute if feasible, delay departurtracks, repair as necessary. Publish and updates warning of weather situation anpreparations for or initiate crew recall or 

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), possible malfunction of track sensors or signal sensors, possible signal malfunctions, rail inspection crews may be required, signal maintenance crew may be required

Advise and update dispatch centers, creaffected areas, review and prepare treaice/snow plan (if warranted), apply chemwarranted. Review procedures for the cforecast. Distribute advisories and updasituation and track conditions. Review c

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), possible malfunction of track sensors or signal sensors, possible signal malfunctions, rail inspection crews may be required, signal maintenance crew may be required, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Advise and update dispatch centers, creaffected areas, implement treatment optice/snow plan (if warranted), apply chemappropriate. Review procedures for currDistribute advisories and updates warnitrack conditions. Initiate crew and re-creincident occurs, initiate HAZMAT spill re

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel SafetyRailway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Weather Needs for Long-Haul Railway Transportation

Freezing Precipitation (ice, inches)

Any Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor 

local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Frozen Precipitation (snow, inches)

>2 and <6 

inches
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Restricted ability of employees to get to work, impedeed/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, probable malfunctions of track sensors and signal sensors, probable signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting), potential increase in ridership (Passenger service increases because roadway mode may not be viable.)

Advise and update dispatch centers, creaffected areas, implement treatment optplan, apply chemical treatment as approoperations to conditions present or forecPublish and distribute advisories, warninregarding weather situation and track corecall and/or re-crew notification/recall. 

Restricted ability of employees to get to work, impedeed/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, probable malfunctions of track sensors and signal sensors, probable signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting), potential increase in ridership (Passenger service increases because roadway mode may not be viable.)

Warn and update dispatch centers, crewaffected areas, prepare and implement ice/snow plan, apply chemical treatmenfor and initiate crew recall, re-crew notifincident occurs, initiate HAZMAT spill re

Restricted ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety when boarding and leaving train), train speed reductions with attendant delays, switch failure likely, malfunctions of track sensors or signal sensors likely, signal malfunction likely, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.)

Advise, warn, and update dispatch centPredict affected areas, prepare treatmeice/snow plan, apply chemical treatmenmodify operations for current or forecastrains, reroute if feasible, delay departurtracks and repair as necessary. Distribuand updates regarding weather situation Initiate and execute crew recall, re-crew 

Restricted ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety when boarding and leaving train), train speed reductions with attendant delays, switch failure likely, malfunctions of track sensors or signal sensors likely, signal malfunction likely, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise, warn, and update dispatch centOutline affected areas, review and initiaexecute ice/snow plan, apply chemical tReview and modify operations for curreSlow or stop trains, reroute if feasible, dstation. Inspect tracks and repair as necadvisories and updates warning of weatconditions. Initiate/execute crew recall anotification/recall. If HAZMAT spill occurreaction/mitigation plan.

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, possible malfunction of track sensors and signal sensors, possible signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.)

Advise, warn, and update dispatch centPredict affected areas, prepare treatmeice/snow plan, apply chemical treatmenmodify operations for current or forecastrains, reroute if feasible, delay departurtracks and repair as necessary. Publish and updates warning of weather situatio

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel SafetyRailway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel SafetyRailway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Frozen Precipitation (snow, inches)

>6 and <8 

inches

Frozen Precipitation (snow, inches)

>8

Drifting Snow (inches) >8
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Reduced ability of employees to get to work, impeded/restricted foot traffic and road use by inspection crews, transportation platform safety (clearing snow off platform, passenger safety boarding and leaving train), train speed reductions with attendant delays, possible switch failure, possible malfunction of track sensors and signal sensors, possible signal malfunction, rail inspection crews may be required, signal maintenance crew may be required, potential increase in ridership (Passenger service increases because other modes are not available.), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise, warn, and update dispatch centIdentify affected areas, initiate treatmenplan, apply chemical treatment, as approperations for current or forecast conditreroute if feasible, delay departure from distribute advisories and updates warnintrack conditions. Initiate/execute crew renotification/recall. Inspect tracks and repHAZMAT spill occurs, initiate reaction/m

Liquid Precipitation Heavy Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Reduced ability of employees to get to work; possible train speed reductions with attendant delays; possible malfunctions of track sensors or signal sensors; possible wash-outs, slides, or high water impacts; potential signal malfunctions; rail inspection crews may be required; signal maintenance crew may be required; possible missed signals due to reduced visibility in heavy rain; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise, warn, and update dispatch centIdentify affected areas, stage equipmenModify operations for current or forecastrains, reroute if feasible, delay departurtracks and repair as necessary. Distriburegarding the weather situation and tracinitiate crew recall, re-crew notification/roccurs, initiate HAZMAT spill reaction/m

Reduced ability of employees to get to work; possible train speed reductions with attendant delays; possible malfunctions of track sensors or signal sensors; possible wash-outs, slides, or high water impacts; potential signal malfunctions; rail inspection crews may be required; signal maintenance crew may be required; possible missed signals due to reduced visibility in heavy rain

Advise, warn, and update dispatch centPredict affected areas, outline affected aequipment and inspection crews. Modify forecast conditions. Slow or stop trains, departure from station. Inspect tracks anDistribute advisories and updates warnitrack conditions. Review and initiate crenotification/recall.

Reduced ability of employees to get to work; possible train speed reductions with attendant delays; possible malfunctions of track sensors or signal sensors; possible wash-outs, slides, or high water impacts; potential signal malfunctions; rail inspection crews may be required; signal maintenance crew may be required; possible missed signals due to reduced visibility in heavy rain; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Advise, warn, and update dispatch centOutline affected areas, stage response Modify operations for current or forecastrains, reroute if feasible, delay departurtracks and repair as necessary. Distribuwarning of weather situation and track ccrew recall, re-crew notification/recall. If initiate HAZMAT spill reaction/mitigation 

Refueling operations delayed, track signal sensor malfunction resulting in possible train delays and stops, crew safety (delay or suspend operations), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise, warn, and update dispatch centPredict/define affected areas. Modify opforecast conditions. Slow or stop trains, departure from station. Inspect tracks, trPublish and distribute advisories and upsituation and track conditions. If HAZMAHAZMAT spill reaction/mitigation plan.

Refueling operations delayed, track signal sensor malfunction resulting in possible train delays and stops, crew safety (delay or suspend operations), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Warn and update dispatch centers, crewaffected areas. Modify operations for cuconditions. Slow or stop trains, reroute ifrom station. Inspect and repair tracks, tDistribute warnings and updates regardtrack conditions. If HAZMAT incident ocreaction/mitigation plan.

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel SafetyRailway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Flooding AnyThunderstorms with Wind, Lightning, or Hail (hail size, proximity to route or operational area in miles)

>1/4 inch, <5 miles 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Reduced ability of employees to get to work, possible train speed reductions with attendant delays, possible malfunctions of track sensors and signals, possible damage to track and/or signals, rail inspection crews may be required, signal maintenance crew may be required, crew, personnel and passenger safety, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Advise, warn, and update dispatch centPredict/define affected areas. Modify opforecast conditions. Slow or stop trains, departure from station. Inspect tracks, trPublish and distribute advisories and upsituation and track conditions. If HAZMAHAZMAT spill reaction/mitigation plan.

Reduced ability of employees to get to work, possible train speed reductions with attendant delays, possible malfunctions of track sensors and signals, possible damage to track and/or signals, rail inspection crews may be required, signal maintenance crew may be required, crew, personnel and passenger safety, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas. Modify operations for cuconditions. Slow or stop trains, reroute ifrom station. Inspect and repair tracks, tDistribute wanings and updates regardintrack conditions. If HAZMAT incident ocreaction/mitigation plan.

increased rail contraction and rail warning signals (The first time each season that the air temperature drops to or below 32 o F causes occurrence of track 

warning signals and potential for derailment.); possible malfunction of track sensors and signals; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay dReview maintenance records to determtrack motion. Inspect and repair tracks, as needed. Distribute advisories, warniregarding weather situation and track co

Increased rail contraction (The first time each cold season that the air temperature drops to or below 32o F causes rail contractions with increased occurrence of track warning signals and potential for derailment.); possible malfunction of track sensors and signals; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, stage resources (equipmoperations for current or forecast conditreroute if feasible, delay departure from tracks, track sensors, and signals. Distrand updates regarding the weather situaIf HAZMAT incident occurs, initiate HAZreaction/mitigation plan.

Increased rail expansion (The first time each warm season that the air temperature rises to or above 70-75o F, rail expansion causes increased 

numbers of track warning signals and potential for derailment.); possible malfunction of track sensors and signal sensors; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety.

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay dReview maintenance records to determtrack motion. Inspect and repair tracks, as needed. Distribute advisories, warniregarding weather situation and track co

Increased rail expansion (The first time each warm season that the air temperature rises to or above 70-75o F, rail expansion causes increased 

numbers of track warning signals and potential for derailment.); possible malfunction of track sensors and signal sensors; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, stage resources (equipmoperations for current or forecast conditreroute if feasible, delay departure from tracks, track sensors, and signals. Distrand updates regarding the weather situaIf HAZMAT incident occurs, initiate HAZreaction/mitigation plan.

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Thunderstorms with Tornadoes (proximity to route or operational area in miles)

<5 miles

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Air Temperature (degrees F, first occurrence of season)

>70o-75o Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Air Temperature (degrees F, first occurrence of season)

<32o
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Continued risk of track contraction, potential for derailment, possible malfunction of track sensors and signal sensors, possible track and/or signal damage, rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (hypothermia, frost bite likely)

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay dReview maintenance records to determtrack motion. Inspect and repair tracks, as needed. Distribute advisories, warninweather situation and track conditions.

Continued risk of track contraction, potential for derailment, possible malfunction of track sensors and signal sensors, possible track and/or signal damage, rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (hypothermia, frost bite likely), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, stage resources (equipmoperations for current or forecast conditreroute if feasible, delay departure from tracks, track sensors, and signals. Distrand updates regarding the weather situaIf HAZMAT incident occurs, initiate HAZreaction/mitigation plan.

Continued risk of track expansion potential for derailment, possible malfunction of track sensors and signal sensors, possible track and/or signal damage, rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (heat exhaustion likely) 

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay dReview maintenance records to determtrack motion. Inspect and repair tracks, as needed. Distribute advisories, warninweather situation and track conditions.

Continued risk of track expansion potential for derailment, possible malfunction of track sensors and signal sensors, possible track and/or signal damage, rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (heat exhaustion likely), increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, stage resources (equipmoperations for current or forecast conditreroute if feasible, delay departure from tracks, track sensors, and signals. Distrand updates regarding the weather situaIf HAZMAT incident occurs, initiate HAZreaction/mitigation plan.

Safety and damage risks (Continued risk of track contraction exists when rail temperature drops to or less than 32 o F.), potential for derailment, possible 

malfunction of track sensors and signal sensors, possible track and/or signal damage, rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (hypothermia, frost bite possible)

Advise and update dispatch centers, creaffected areas, pre-stage resources (eqModify operations for current or forecastrains, reroute if feasible, delay departurmaintenance records to determine areamotion. Distribute advisories and updatesituation and track conditions. 

Safety and damage risks (Continued risk of track contraction exists when rail temperature drops to or less than 32 o F.), potential for derailment, possible 

malfunction of track sensors and signal sensors, possible track and/or signal damage; rail inspection crews may be required, signal maintenance crew may be required, health and safety risks (hypothermia, frost bite possible)

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay Review maintenance records to determtrack motion. Distribute advisories, warnregarding weather situation and track co

Continued risk of track expansion when rail temperature rises to or above 110o F (~20o to 30o F above the neutral installation temperature); potential for 

derailment; possible malfunction of track sensors and signal sensors; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety

Advise, warn, and update dispatch centPredict affected areas, pre-stage resourcrews). Modify operations for current or or stop trains, reroute if feasible, delay dReview maintenance records to determtrack motion. Inspect and repair tracks, as needed. Distribute advisories, warniregarding weather situation and track co

Continued risk of track expansion when rail temperature rises to or above 110o F 

(~20o to 30o F above the neutral installation temperature); potential for 

derailment; possible malfunction of track sensors and signal sensors; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; crew, personnel, and passenger safety; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting) 

Warn and update dispatch centers, crewaffected areas, stage resources (equipmoperations for current and forecast condreroute if feasible, delay departure from tracks, track sensors, and signals. Distrand updates regarding the weather situaIf HAZMAT incident occurs, initiate HAZreaction/mitigation plan.

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Air Temperature (degrees F) >90o Railway/Control Center Operations: monitor, advise, control system integrity. 

Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Air Temperature (degrees F)

<0o

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Rail Temperature (degrees F)

 >110o Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Rail Temperature (degrees F) <32o with moisture
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Soil Temperature, Freezing or Thawing Trend (degrees F)

Decreasing to <32o or 

increasing to >32o

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Risk of railbed motion/movement from ground heave (Ground heave is most prevalent during autumn freezes and spring thaws.), construction and inspection delays likely, possible failure of track and railbed; possible derailment; increased risk of HAZMAT incidents, public relations effects

Issue advisories to rail management anincreasing rail remote sensing interval oSchedule additional system monitoring crews/re-crews as required. Initiate altemaintenance work schedule. Ensure peclothing and footwear for snow and ice. topography and failure location for remeHAZMAT incident occurs, initiate HAZMplan. 

Crew, personnel, and passenger safety (hypothermia, frost bite); potential operational delays.

Advise operators, monitor personnel, mPlan to increase available manpower. Inappropriately for cold weather and ensugear is available.

Crew, personnel, and passenger safety (hypothermia, frost bite); potential operational delays.

Advise operators, monitor personnel, mLimit personnel time outside, increase athat crews are clothed appropriately for 

Safety and health risk (heat exhaustion), potential operational delays Advise operators, break shifts, restrict o

to increase available manpower, insist tappropriately for hot weather.

Safety and health risk (heat exhaustion), potential operational delays Advise operators, break shifts, restrict o

personnel time outside, increase availabcrews are clothed appropriately for hot w

Construction: scheduling, maintenance, repair. Personnel Safety Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center.

Heat Index (degrees F) >105o Construction: scheduling, maintenance, 

repair. Personnel Safety Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center.

Wind Chill (degrees F) <-20o 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Crew, personnel and passenger safety risks; missed signals, obstructions on track, etc.; increasing risks of collisions and derailments; reduced speed; delays in service; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators, reduce speeds or stoIf HAZMAT incident occurs, initiate spill 

Crew, personnel and passenger safety risks; missed signals, obstructions on track, etc.; increasing risks of collisions and derailments; reduced speed; delays in service; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators, reduce speeds or stoIf HAZMAT incident occurs, initiate spill 

Crew, personnel, and passenger safety risks; damage risk; rail car blow over likely; schedule delays; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators/operations, review optoperations. If HAZMAT incident occurs, reaction/mitigation plan. 

Crew, personnel, and passenger safety risks; damage risk; rail car blow over likely; schedule delays; possible track and/or signal damage; rail inspection crews may be required; signal maintenance crew may be required; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators/operations, review optoperations. If HAZMAT incident occurs, reaction/mitigation plan. 

Hurricane: Winds, Sea State, Tidal Surge, Flooding

Any Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Safety risks to personnel and equipment (possible injury or death from accidents); railway roadbed scoured, buried, damaged or destroyed; rail damage from line stretch and foreign debris impact; winds, seas, tides may restrict or suspend coastal rail traffic; rail sensor failure likely; possible railbed or track failures and derailments; increased monitoring of crews and equipment required; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting); potential for disrupted construction or maintenance cycles; public relations effects

Acquire hurricane advisories and/or warand/or warnings to rail management and number of visual inspections and rail remIncrease rail surveillance; check for bridintegrity. Consider the effects of topografor remediation and reclamation. Assign as required. If HAZMAT incident occursreaction/mitigation plan. Ensure proper Restrict or suspend rail operations. Ressuspend aerial and vehicle track inspecsafety. Initiate alternate construction/maEnsure proper clothing and footwear are and flooded walkways and road surface

Earthquake: Land Motion, Landslides, Avalanches, Etc.

Any Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Safety risks to personnel and equipment (accidents are likely with possible injury or death); railway roadbed scoured, buried, damaged or destroyed; rail damage from line stretch and foreign debris impact likely; rail sensor failure likely; increased monitoring of crews and equipment; increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting); public relations effects

Issue advisories to rail management annumber of visual inspections and rail remConsider the effects of topography and remediation and reclamation. Schedule monitoring queries, assign additional creInitiate fuel management contingency pcancel transfers, etc) based on impact oincident occurs, initiate HAZMAT spill re

Railway/Control Center Operations: monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Wind: Head, Cross, or Tail (wind speed in miles per hour)

>50 mph Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Visibility, including Restriction (statute miles)

<1 mile, 

<1/2 mile
Weather Element Threshold Activity Impacts Action 

Weather Needs for Long-Haul Railway Transportation

Nuclear, Biological or Chemical Release

Any Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor 

local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Safety risks to personnel and equipment; increased monitoring of crews and equipment (During a rail failure, vapors and toxins are released to the envrionment with possible/likely catastrophic results. Accidents are likely with possible injury or death.)

Acquire output from atmospheric transpdepicting the horizontal and vertical distvapor. Issue advisories and/or warnings operators. Initiate/execute HAZMAT spiEnsure proper authorities are notified.

GPS navigation disrupted, radio/cellular phone communications disrupted, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators, monitor communicatiofor alternate communications methods.

GPS navigation disrupted, radio/cellular phone communications disrupted, increased risk of hazardous material spill (increased monitoring, mitigation, reclamation, reporting)

Advise operators, monitor communicatioalternate communications methods.

Railway/Control Center Operations: 

monitor, advise, control system integrity. Station & Depot Operations: monitor 

local operations, advise Control Center. Hump Yard Operations: maintenance, inspections, local operations, advise Control Center. Construction: scheduling, maintenance, repair. Hazardous Material: monitoring, mitigation, reclamation, reporting. Surveillance: inspections, monitoring, maintenance. Personnel Safety

Space Weather (solar flares etc.)

Any
Weather Information for Surface Transportation

Appendix B–3

U.S. Marine Transportation System WIST Needs Template
Weather Information for Surface Transportation

U.S. Marine Transportation System Sector Activities

Inland water activities

Ferries

Commerce. Includes barge traffic on major rivers.

Recreational Boating. Includes fresh water lakes, rivers and streams.

Open water activities

Cargo/freight. Includes large ocean-going vessels, including U.S. Navy ships

Cruise lines

Commercial fishing. Primarily includes near-shore and off-shore salt water operations.

Recreational Boating. Salt-water operations.

Port operations. Operations include keeping port facilities open and safe movement of vessels in and out.

St. Lawrence Seaway operation. Operation of locks and canals, control of navigation and movement of vessels.

NASA movement of launch vehicle/payload elements via barge. Primarily external fuel tank and solid rocket

boosters moving to and from the launch facility.

Marine Modeling. Forecasting oceanographic conditions for waterway and coastal operations to specifically

improve predictions of water levels to facilitate ships entering/leaving ports.
Weather Element Threshold Activity Impacts Action 

All inland activities (ferries, boating, commerce), all open water activities (boating, cargo/freight, cruise lines, and fishing) 

Possible injury to personnel because of ice covered decks and walkways, impaired equipment operation due to ice cover, line handling difficult because of ice, schedule delays due to time required for ice removal

Take precautions such as limiting equipment to keep it clear of ice. periods or in areas of freezing rain

NASA movement of launch vehicle and payload elements via barge

Risk to personnel, equipment and cargo from ice buildup

Consider restricting ondeck activit

cargo. Delay barge movement. 

St. Lawrence Seaway operations

Vessel lockage operations delayed/suspended (dangerous conditions for lock linehandlers)

Apply sand and salt to surfaces. 

Port operations Difficult ground travel, cargo handling, equipment 

operation, etc., because of ice

Implement snow/ice emergency p

 Any All inland activities (ferries, 

boating, commerce), all open water activities (boating, cargo/freight, cruise lines, and fishing) 

Possible injury to personnel from snow-covered decks and walkways, reduced visibility (depending on rate of snowfall), impaired equipment operation 

Take precautions such as limiting equipment to keep the equipment 

Any NASA movement of launch 

vehicle and payload elements via barge

Risks to personnel, equipment, and cargo from snow buildup

Consider restricting ondeck activit

cargo. Delay barge movement. 

>4 inches Port operations Difficult ground travel, cargo handling, equipment 

operation, etc., because of snow 

Implement snow/ice emergency p

Heavy St. Lawrence Seaway 

operations

See Visibility weather element If equipped with radar, use it for n

clearance. Otherwise exercise extspeed as conditions require.

Drifting Snow Any Port operations Travel difficult due to blowing snow and reduced 

visibility, snow clearing operations hampered

Impement snow/ice emergency pl

All inland activities (ferries, boating, commerce)

Impaired operations due to reduced visibility, danger to

personnel, and equipment from flooding

Exercise caution and reduce speebelow 1 statute mile, modify or deconditions improve.

All open water activities (boating, cargo/freight, cruise lines, and fishing) 

Operations impaired by reduced visibility Increase vigilance and reduce spe

NASA movement of launch vehicle and payload elements via barge

Operations impaired by reduced visibility Increase vigilance and reduce spe

St. Lawrence Seaway operations

Visual navigation restricted, risk of collisions increased If equipped with radar, use it for n

clearance. Otherwise exercise extspeed as conditions require.

Port operations Flooding possible Move equipment to high ground a

Any Marine modeling Freshwater inputs important to models Improve model results by making 

All inland activities (ferries, boating, commerce)

Danger to all inland activities, including lock operations, from high water levels and swift currents

Restrict/suspend operations until tpassed. 

Rain (intensity) Heavy Flooding Any

Weather Needs for the Marine Transportation System, including Inland Waterway and Open Water Activit

Freezing Rain AnySnow (inches)
Weather Element Threshold Activity Impacts Action 

Weather Needs for the Marine Transportation System, including Inland Waterway and Open Water Activit

NASA movement of launch vehicle and payload elements via barge

Potential problems in handling barges because of high water levels and swift currents

Restrict/suspend operations until tpassed. 

Port operations Operations disrupted, facilities damaged Implement emergency proceduresMarine modeling Modeling of estuarine dynamics affected by freshwater inMake more data available (e.g., h

real-time data needed to provide bestuarine models).

Port operations Potential damage to port facilities from flooding and 

from vessals tied alongside 

Exercise extra vigilance in tending alongside. Decide whether large s

Recreational boating Potential damage to moored boats Arrange mooring lines for significaFerries Increased potential for groundings, potential damage to

docks and terminals, impaired accessibility for passengers (particularly those with disabilities) 

Modify operations as required. 

Marine modeling Estuarine models affected by coastal boundary 

conditions

Iimprove model results by making conditions available.

Inland recreational boating Reduced passenger comfort, increased risk to small 

boats 

Warn small boats to exercise caut

Open water recreational boating Reduced passenger comfort, increased risk to small 

boats 

Exercise caution, adjust speed ac

Inland recreational boating, ferries, and commerce

Potential safetly risks to crew and passenge; potential hull damage to small boats; open barges may take on water, depending on loading

Exercise extreme caution, stop smpassengers. Modify ferry operatiosuspend operations.

Open water recreational boating, open water cruise lines 

Risks to personnel, possible hull damage, reduced passenger comfort

Boats should reduce speed, exercpassengers. 

Port operations Possible damage to port facilities Implement emergency proceduresInland ferries Safety risk to crew and passegers, damage risk to 

cargo

Advise passengers, secure cargo

Open water recreational boating, cargo/freight, cruise lines, and fishing

Safety risk to crew and passengers If encounter unavoidable, adjust c

Ensure cargo is secure, consider activities. 

Port operations Likely damage to port facilities Implement emergency procedures

>10 feet NASA movement of launch 

vehicle and payload elements via barge

Risk to personnel, possible damage to very sensitive, high value space program resources 

Consider delaying movements un

>12 feet Open water cargo/freight, 

cruise lines, and fishing

Safety risk to crew and passengers, potential for damage to cargo and structural damage to the ship

Ensure cargo is secure. Consider 

weather decks. Ensure freeing pospeed/course for best ride. Imple

Any Marine modeling Wave effects on model dynamics, mixing Include waves in models to improv

Inland Waterway Ice (coverage)

 Any All inland activities (ferries, 

boating, commerce)

All activities threatened by potential hull damage from ice 

Change course and/or speed to aice breaking services.

4 to 6 feet6 to12 feet2 to 4 feet

Storm Surge or Abnormal High/Low Tides 

Any

Wind Wave Height (feet) 
Weather Element Threshold Activity Impacts Action 

Weather Needs for the Marine Transportation System, including Inland Waterway and Open Water Activit

River Ice, Ice Gorging (coverage)

Any Inland commerce Damage risk to vessels, vessels may become 

icebound

Reduce tow size for better maneu

if conditions prevent safe passageservices. 

All open water activities (cargo/freight, cruise lines, and fishing) 

All activities threatened by potential hull damage from sea ice 

Change course and/or speed to a

Port operations Possible damage to port facilities including docks, 

piers, and watercraft

Be prepared to keep ice away from 

Freezing Spray (seas and low temperature)

Any All open water activities 

(boating, cargo/freight, cruise lines, and fishing) 

Reduced stability, ice loading may exceed maximum weight limit

Change heading and/or speed to Remove as much ice as possible. improve, seek shelter. 

Thunderstorms with Lightning or Hail (distance from operation in statute miles)

5 statute miles All inland activities (ferries, 

boating, commerce)

Risk to personnel from lightning, potential damage to damage to cargo and injury to crew and passengers from hail, threats to barge tow equipment and personnel from reduced visibility and wind

Stop boating activities. Exercise cStop outside work, reduce speed.

All open water activities (boating, cargo/freight, cruise lines, and fishing) 

Risk to personnel from lightning, potential damage to cargo and injury to crew and passengers from hail, impaired ability to see and be seen from reduced visibility

Delay departure until storm has paspeed to avoid storm. Consider reweather decks. 

NASA movement of launch vehicle and payload elements via barge

Potential for injury to personnel, possible damage to very sensitive, high value space program resources

Delay departure until conditions imactivities. Adjust course and speepossible. 

Port operations Safety risk to personnel, damage risk to port facilities Implement wind/hurricane/tornado 

Thunderstorms with Tornado or Waterspout (distance from operation in statute miles)

25 statute miles

All inland activities (ferries, boating, commerce)

Serious threat to all inland activities from tornadoes or waterspouts

Adjust course and/or speed to avo

All open water activities (boating, cargo/freight, cruise lines, and fishing) 

Serious threat to all open water activities from waterspouts

Adjust course and/or speed to avo

Port operations Safety risk to personnel, damage risk to port facilities Implement wind/hurricane/tornado 

Inland ferries and commerce Risks to crew, passengers, and equipment Ensure that proper clothing is avaOpen water cargo/freight, cruise lines, and fishing

Health hazard to personnel, equipment operation impaired

Ensure proper clothing is available equipment is properly maintained operations. 

Port operations Risk to operators and equipment Ensure that proper clothing is ava

>90o All MTS activities (10) Risk to personnel from heat exhaustion, risk to 

equipment from overheating

Advise operators. Ensure proper cavailable. Monitor equipment and 

Air Temperature 

(degrees F) 

<32o 

Thunderstorms with Lightning or Hail (distance from operation in nautical miles)

5 nautical miles

Thunderstorms with Tornado or Waterspout (distance from operation in nautical miles)

20 nautical miles

Open Water Sea Ice Any
Weather Element Threshold Activity Impacts Action 

Weather Needs for the Marine Transportation System, including Inland Waterway and Open Water Activit

>90o NASA movement of launch 

vehicle and payload elements via barge

Risk to personnel from heat exhaustion, risk to equipment from overheating, possible damage to very sensitive, high value space program resources 

Advise operators. Ensure proper cavailable. Monitor equipment and Protect cargo. 

All Marine modeling Air temperature effects on heat flux in models Include data on air temperature an

interactions to improve model resu

All inland activities (ferries, boating, commerce)

Threat to all inland activities if waterways freeze over Monitor water conditions and mod

required.

St. Lawrence Seaway operations

Underpowered vessels may become icebound Restrict certain vessels from oper

power-to-length ratio. 

All Marine modeling Water temperature important as initial condition for 

models

Improve model results by incorpordata.

Heat Index (degrees F) >105o All MTS activities (10) Risk to personnel from heat exhaustion Ensure that personnel wear prope

and limit exposure.

Wind Chill (degrees F) <20o All MTS activities (10) Risk to personnel from hypothermia and frost bite Ensure that personnel wear prope

exposure.

1 statute mile Inland recreational boating3 statute miles Inland ferries1 mile or less Inland commerce<1/8 nautical 

mile

NASA movement of launch vehicle and payload elements via barge 

No movement when visibilities are below threshold Wait for improved conditions. 

3 nautical miles

All open water activities (boating, cargo/freight, cruise lines, and fishing) 

Reduced ability to maintain visual clearance, visual navigation restricted

If equipped with radar, use it for n

clearance. Otherwise exercise exspeed as conditions require. 

1 nautical mile Port operations Reduced ability to maintain visual clearance Consider delaying ship movement 

1/4-1/2 nautical mile

Reduced ability to maintain visual clearance Suspend two-way navigation. Con

<1/4 nautical 

mile

Reduced ability to maintain visual clearance Stop all vessel movements. 

Glare Any All MTS activities Difficult to see for navigation and avoidance Consider adjusting heading and/o

25 mph All inland activities (ferries, 

boating, commerce)

Small boat handling may be difficult; control during ferry docking may be impaired; difficulty handling empty barges in tow; depending on wind direction, tows may become windbound; if wind opposes tidal current, expect increased wave heights 

Warn all operators to exercise causmall boat operations. 

All Marine modeling Wind provides surface momentum flux to models To improve models, include wind <32 Water Temperature o 

(degrees F) Visibility (statute miles) Visual navigation restricted, risk of collisions increased If equipped with radar, use it for n

clearance. Otherwise exercise extspeed as conditions require. 

Visibility (nautical miles)

St. Lawrence Seaway operations

Wind Speed and Direction (speed in miles per hour)
Weather Element Threshold Activity Impacts Action 

Weather Needs for the Marine Transportation System, including Inland Waterway and Open Water Activit

20 knots Open water boating and fishing Boat handling difficulties because of wind and seas Advise all operators to exercise ca

small boat operations. 

25 knots Port operations Possible wind damage to port facilities Implement Emergency Wind Proc

delaying ship movements. 

35 mph All inland activities (ferries, 

boating, commerce)

Small boat handling and control difficulties because of wind and seas, control during docking impaired, difficulty handling empty barges in tow 

Operations by small boats are not Operators of ferries and commerccaution. If appropriate, stop opera

i

30 knots All open water activities 

(boating, cargo/freight, cruise lines, and fishing) 

Minimal to extreme difficulty maintaining control, depending on size of vessel 

Operations by small boats are not Cargo/freight, cruise line, and fishexercise caution and modify operarequire. 

15-20 knots St. Lawrence Seaway 

operations

Winds may affect vessel maneuverability, especially vessels in ballast conditions; normal flow of canal traffic may be interrupted 

Require Seaway Entities to enforvessels to anchor, as appropriate

30 knots Port operations Possible damage to port facilities Implement Emergency Wind Proc

delaying ship movements. 

50 mph All inland activities (ferries, 

boating, commerce)

Extreme difficulty with handling and maintaining control likely

Modify operations as required by 

45 knots Open water cargo/freight, 

cruise lines, and fishing

Likely difficulty with handling and maintaining control Adjust course and speed for best Likely damage to port facilities Begin preparation activities. Ship handling becomes difficult Implement emergency wind proce

ship movements. 

Air Qualilty (characterization/code)

Unhealthful/ red

All MTS activities (10) Health and safety risks to operators, passengers, and 

crew

Advise operators and modify oper

Space Weather (solar flares, etc.)

Any All MTS activities (10) Degraded GPS navigation and radio/cellular 

communications

Advise operators and monitor com

Volcanic ash Any All MTS activities (10) Reduced visibility, health hazard, damage to 

equipment from ash accumulation

Protect equipment, have breathing preparations to clear ash, curtail o

Nuclear, Biological, or Chemical Dispersion 

Any All MTS activities (10) Severe threat to life, health and safety risks (dispersion 

of extremely dangerous hazardous materials, agents, or substances)

Notify operators. Do not travel in a

Port operations

Wind Speed and Direction (speed in knots or miles per hour)

45 knots
Weather Information for Surface Transportation

Appendix B–4

Pipeline Sytems WIST Needs Template
Weather Information for Surface Transportation

Pipeline Systems Sector Activities

Control center operations. Operations to monitor the pipeline system, advise system operators, and

control system integrity.

Pumping station operations. Responsible for fuel movement, allocation, storage, and distribution.

Well head/drill site operations. Includes operations for fuel pumping, storage, and distribution near

source wells.

Tank farm operations. Includes fuel storage, distribution, and maintenance at tank farms.

Construction. Operations include construction, maintenance, and repair, as well as the scheduling of

these operations.

Hazardous material. Includes monitoring storage and transport of hazardous materials and any

mitigation, reclamation, and reporting operations associated with their accidental release while

within the pipeline system.

Surveillance. Includes inspections, monitoring, and maintenance.

Personnel safety. Any operation where safety and health risks to workers or others may be present.

Fuel barge operations. Includes barge docking, fuel movement by barge, and transfer to/from fuel

barges.
Weather Element Threshold Activity Impacts A

Issue communication advisorimanagement and operators. Icontingency plans (re-route, spipeline scheduler will make aterminals/customers to accomdisruptions. Initiate de-icing owalkways, valves, gauges, etctopography and leak/pipe failureclamation. Increase the numpipeline remote monitoring effinspections, assign additional HAZMAT incident occurs, initireaction/mitigation plan. EnsuInitiate alternate construction/Postpone any work that can wEnsure proper clothing and foMonitor crews and equipmentsuspend aerial and vehicle pipweather safety. Check integritvalves. Check liquid level in tahomogeneity and purity. RepoNSC. Monitor communicationmodes as necessary. Initiate pipeline sensor data distributio

Frozen Precipitation(snow, inches)

Any to <8 inches

Control Center Operations : monitor, advise, control system integrity.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Inoperative valves or valve failure from freezing, damage to valves or gauges during snow removal, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, possible disruption of construction or maintenance cycles, safety of personnel and equipment (proper clothing and monitoring of crews and equipment required), buried pipeline inspections (digging out an inspection trench or bore hole) may be complicated by ice and frozen soil, construction and inspection delays likely, public relations impacts

Issue advisories to pipeline mInitiate snow removal program gauges, etc.). Consider the efleak/pipe failure location for reIncrease the number of visual monitoring efforts. Schedule aadditional crews/re-crews, as occurs, initiate HAZMAT spill alternate construction/maintenany work that can wait until thclothing and footwear for snow pipelines, tanks, and valves. Csample the liquid for homogenIssue communication advisorimanagement and operators. Icontingency plans (re-route, spipeline scheduler will make aterminals/customers to accomdisruptions. Initiate snow remoprogram for roads, walkways, the effects of topography and remediation and reclamation. inspections and pipeline remoadditional inspections, assign required. If HAZMAT incident reaction/mitigation plan. EnsuInitiate alternate construction/Postpone any work that can wEnsure proper clothing and fo

Frozen Precipitation(snow, inches)

Control Center Operations : monitor, advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

>8 inches Inoperative valves or valve failure from freezing, damage to valves or 

gauges during snow removal, disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, re-routing, unscheduled storage), pipeline sensor failure likely, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (accidents are likely on snow-covered walkways and roads, proper clothing and monitoring of crews and equipment required), possible injury or death, buried pipeline inspections (digging out an inspection trench or bore hole) may be complicated by ice and frozen soil, construction and inspection delays likely, satellite/radio/cellular phone communications may be disrupted, communications and data distribution from pipeline sensors may fail during heavy snow eventsInoperative valves or valve failure from freezing, damage to valves or gauges during ice removal, disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, rerouting, unscheduled storage), pipeline sensor failure likely, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (accidents are likely due to icy conditions, proper clothing and monitoring of crews and equipment required), possible injury or death, buried pipeline inspections (digging out an inspection trench or bore hole) may be complicated by ice and frozen soil, construction and inspection delays likely, satellite/radio/cellular phone communications may be disrupted, communications and data distribution from pipeline sensors may fail during ice storms

Any Control Center Operations : monitor, 

advise, control system integrity. Pumping Station Operations : fuel movement, allocation, storage, distribution. Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance. Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Weather Needs for Pipeline System Operations

Freezing Precipitation (ice)
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Monitor crews and equipmentsuspend aerial and vehicle pipweather safety. Check integritvalves. Check liquid level in tahomogeneity and purity. RepoNSC. Monitor communicationmodes as necessary. Initiate pipeline sensor data distributioIssue communication advisorimanagement and operators. Icontingency plans (re-route, spipeline scheduler will make aterminals/customers to accomdisruptions. Initiate snow remoprogram for roads, walkways, the effects of topography and remediation and reclamation. inspections and pipeline remoadditional inspections, assign required. If HAZMAT incident reaction/mitigation plan. EnsuInitiate alternate construction/ Postpone any work that can wEnsure proper clothing and foMonitor crews and equipmentsuspend aerial and vehicle pipweather safety. Check integritvalves. Check liquid level in tahomogeneity and purity. RepoNSC. Monitor communicationmodes as necessary. Initiate pipeline sensor data distributio

Liquid Precipitation Heavy Control Center Operations : monitor, 

advise, control system integrity.Construction: scheduling, maintenance, repair.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Safety of personnel and equipment, possible workplace injury or death (Accidents are likely on rain slick surfaces; proper clothing is required.), possible disruption of inspection, construction, or maintenance cycles, inspections of buried pipeline (digging out an inspection trench or bore hole) may be complicated by standing water, satellite/radio/cellular phone communications disruptions, possible failure of communications and data distribution from pipeline sensors during heavy precipitation

Issue advisories to pipeline mInitiate alternate construction/Postpone any work that can wEnsure proper clothing and foReschedule/restrict aerial and based on weather safety. Inspand water impounds; drain/pufor the heavy rain. Issue commcommunication failure to NSCoutages, utilize alternative mocontingencies for pipeline sen

Drifting Snow (inches)

Inoperative valves or valve failure from freezing, damage to valves or gauges during snow removal, disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, re-routing, unscheduled storage), pipeline sensor failure likely, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (accidents are likely on snow-covered walkways and roads, proper clothing and monitoring of crews and equipment required), possible injury or death, buried pipeline inspections (digging out an inspection trench or bore hole) may be complicated by ice and frozen soil, construction and inspection delays likely, satellite/radio/cellular phone communications may be disrupted, drifting snow may cause communications and data distribution failures from pipeline sensors

Control Center Operations: monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

>8 inches
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Issue advisories and/or warnioperators. Initiate fuel manageroute, store, cancel transfers, make arrangements with shipaccommodate the schedule dtopography and leak/pipe failureclamation. Increase the numpipeline remote monitoring effinspections; check for bridge, integrity. Assign additional creHAZMAT incident occurs, initimitigation plan. Ensure propealternate construction/maintenany work that can wait until thEnsure proper clothing and fowalkways and road surfaces. aerial and vehicle pipeline inssafety. Check integrity of pipeliquid level in tanks, sample thDrain or fill pipelines to decreaappropriate.Acquire wind advisories and/obarge operations and tank corepair. If conditions become uthe building and go to the strathe SBS controllers can monitInitiate fuel management contcancel transfers, etc.) based oThe pipeline scheduler will maand terminals/customers to acdisruption. Consider the effecfailure location for remediation number of visual inspections aefforts. Schedule additional intrestles, pipeline roadbed intecrews, as required. If HAZMAHAZMAT spill reaction/mitigatconstruction/maintenance woclothing and footwear are worRestrict or suspend fueling opor suspend aerial and vehicle weather safety. Check integritvalves. Check liquid level in tahomogeneity and purity. Issue report communications failure alternative modes. Initiate bacdata distribution.

Flooding Pipeline roadbed scoured or buried pipeline unearthed, pipeline 

damage from line stretch and foreign debris impact, disruption of fuel delivery resulting in fuel management emergency procedures (reallocation, transfer delays, re-routing, unscheduled storage), pumping may be restricted or suspended, pipeline sensor failure likely, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (monitoring of crews and equipment required; accidents are likely with possible injury or death), buried pipeline inspections (digging out an inspection trench or bore hole) may be complicated by standing water

Control Center Operations : monitor, advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Any

Thunderstorms with Lightning, Hail, or Tornadoes (proximity to route or operational area in miles)

within 5 miles Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Pipeline roadbed scoured or buried pipeline unearthed, pipeline damage from line stretch and foreign debris impact, disruption of fuel delivery resulting in fuel management emergency procedures (reallocation, transfer delays, re-routing, unscheduled storage), pumping may be restricted or suspended, pipeline sensor failure likely, possible disruption of construction or maintenance cycles (Fuel tank construction/repair is very wind sensitive--large sail area.), possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (monitoring of crews and equipment required; accidents are likely with possible injury or death), satellite/radio/cellular phone communications disruptions, communications and data distribution from pipeline sensors may fail during thunderstorms (effects of tornadoes, lightning, hail)
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

<32o with 

moisture

Control Center Operations : monitor, advise, control system integrity.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Inoperative valves or valve failure from freezing, damage to valves or gauges during ice/snow removal, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, safety of personnel and equipment (proper clothing and monitoring of crews and equipment required)

Issue advisories to pipeline mInitiate snow removal program gauges, etc.). Schedule additassign additional crews/re-creeffects of topography and leakremediation and reclamation. of visual inspections and pipePostpone any work that can wEnsure proper clothing and fointegrity of pipelines, tanks, antanks, sample the liquid homoincident occurs, initiate HAZM

<-20o Construction: scheduling, maintenance, 

repair. Personnel Safety

49 CFR 193.2137 sanctions for plastic pipes, safety of personnel and equipment (proper monitoring of crews and equipment required)

Advise operators of exposure equipment. Enforce prohibitio

>100o Construction: scheduling, maintenance, 

repair. Personnel Safety

Safety of personnel and equipment (proper monitoring of crews and equipment for heat stress required), 49 CFR 193.2137 sanctions for plastic pipes.

Advise operators of heat stresand equipment. Review and fopipe.

>150o Construction: scheduling, maintenance, 

repair.

49 CFR 193.2137 sanctions for plastic pipes Enforce prohibition on thermo

Soil Temperature (degrees F)

 <32o Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Possible pipeline motion/movement from ground heave (Ground heave is most prevalent during autumn freezes and spring thaws.), buried pipeline inspections (digging out the inspection trench or bore hole) may be complicated by frozen soil, construction and inspection delays likely, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, potential regulatory restrictions on gas lines under 49 CFR 193.2137 and 193.2065

Issue advisories to pipeline mConsider increasing pipeline rphysical inspections. Schedulqueries, assign additional crewConsider the effects of topogrlocation for remediation and reoccurs, initiate HAZMAT spill alternate construction/maintenany work that can wait until thclothing and footwear for snow pipelines, tanks, and valves. Csample the liquid homogeneit

Wind Chill (degrees F)

<20o Control Center Operations : monitor, 

advise, control system integrity.Construction: scheduling, maintenance, repair.Personnel Safety

Personnel exposure (hypothermia, frost bite), limited time outside for maintenance personnel, personnel safety procedures strictly enforced (buddy system, time outside limited and actively managed)

Limit personnel time outside. Insist that ground crews are cweather; ensure that cold wea

Heat Index (degrees F)

>105o Control Center Operations : monitor, 

advise, control system integrity.Construction: scheduling, maintenance, repair.Personnel Safety

Personnel exposure (heat stroke/heat exhaustion), personnel safety procedures strictly enforced

Limit personnel time outside. Insist that ground crews are cweather.

Air Temperature(degrees F)
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Cooling or Heating Degree-Days Vairable Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.

Fuel management impacts (Based on prediction of cooling and heating degree days, fuel demand can vary dramatically. Proper fuel types can be readied for distribution based on customer demand. Although this is principally a petroleum industry concern, it also affects management of pipeline fuel distribution.) 

Issue advisories to pipeline mReallocate resources to respoclient/customer demand, if fea

Visibility(statute miles)

<1/4 mile Control Center Operations : monitor, 

advise, control system integrity.Tank Farm Operations : storage, distribution, maintenance.Fuel Barge Operations : docking, fuel movement.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Restricted or suspended movement of barge and tanker traffic from/to off-shore drill sites to/from coastal pumping facilities, restricted or suspended surveillance of pipelines by air or truck, disruption of fuel delivery resulting in fuel management emergency procedures (reallocation, transfer delays, re-routing, unscheduled storage), pumping may be restricted or suspended, safety of personnel and equipment (monitoring of crews and equipment required), accidents are likely with possible injury or death, possible disruption of construction or maintenance cycles

Issue advisories to pipeline mModify, restrict, or suspend baReallocate resources to respodemand, if feasible. Rescheduand vehicle pipeline inspectioCheck integrity of pipelines, talevel in tanks; sample the liqu

Acquire wind advisories and/obarge operations and tank corepair. Issue advisories and/omanagement and operators. Icontingency plans (re-route, sbased on impact of high windstopography and leak/pipe failureclamation. Increase the numpipeline remote monitoring effinspections; check for bridge, integrity. Assign additional creHAZMAT incident occurs, initireaction/mitigation plan. EnsuInitiate alternate construction/Postpone any work that can wModify, restrict, or suspend taor repairs. Restrict or suspend Reschedule, restrict, or suspeinspections based on weather pipelines, tanks, and valves. Csample the liquid homogeneit

>200 mph Construction: facility regulations. Facility design must conform to wind restrictions in 49 CFR 193.2067 Ensure construction complian

requirements as spelled out in 

Winds, Speed and Direction (speed in miles per hour)

Restricted or suspended movement of barge traffic from/to off-shore drill sites to/from coastal pumping facilities, disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, re-routing, unscheduled storage), pumping may be restricted or suspended, pipeline sensor failure likely, possible disruption of construction or maintenance cycles (Fuel tank construction/repair is very wind sensitive--large sail area.), possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (Accidents are likely with possible injury or death, monitoring of crews and equipment is required.) 

>60 mph Control Center Operations : monitor, 

advise, control system integrity.Tank Farm Operations : storage, distribution, maintenance.Fuel Barge Operations : docking, fuel movement. Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Acquire hurricane advisories aduring barge operations and tor repair. Issue advisories andmanagement and operators. Ithe control center, controllers go to the strategic back up sitcontrollers can monitor and opreturn to the primary control cInitiate fuel management contcancel transfers, etc.) based opipeline scheduler will make aterminals/customers to accomConsider the effects of topogrlocation for remediation and reof visual inspections and pipeIncrease pipeline surveillancepipeline roadbed integrity. Assas required. If HAZMAT incidereaction/mitigation plan. EnsuInitiate alternate construction/Postpone any work that can wEnsure proper clothing and fowalkways and road surfaces. operations. Reschedule, restrvehicle pipeline inspections baintegrity of pipelines, tanks, antanks; sample the liquid homopipelines to decrease damage Acquire seas advisories and/obarge operations and off-shormaintenance, or repair. Issue pipeline management and opewill make arrangements with scustomers to accommodate thfuel management contingency transfers, etc.) based on impaof topography and leak/pipe faand reclamation. Increase the and pipeline remote monitorininspections; check pipeline intcrews/re-crews, as required. Iinitiate HAZMAT spill reactionEnsure proper authorities are and footwear for slick and flooshipboard surfaces. Initiate almaintenance work schedule. tanks, and valves. Check liquliquid homogeneity and puritydecrease damage susceptibil

Seas >12 feet(wave height in feet)

Seafloor pipeline damaged or destroyed; buried pipeline unearthed, damaged or destroyed; pipeline damage from line stretch, foreign debris impact, and corrosion from damaged coating; restricted or suspended movement of barge traffic from/to off-shore drill sites to/from coastal pumping facilities due to high seas; disruption of fuel delivery resulting in fuel management emergency procedures (reallocation, transfer delays, re-routing, unscheduled storage); pumping may be restricted or suspended; pipeline sensor failure likely; possible disruption of construction or maintenance cycles; possible leaks or other pipeline failures; HAZMAT procedures may be initiated; public relations impacts; safety of personnel and equipment (monitoring of crews and equipment required; accidents are likely with possible injury or death)

Control Center Operations : monitor, advise, control system integrity.Pumping Station Operations: fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : 

pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Fuel Barge Operations : docking, fuel movement.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Pipeline roadbed scoured or buried pipeline unearthed, pipeline damage from line stretch and foreign debris impact, restricted or suspended movement of barge traffic from/to off-shore drill sites to/from coastal pumping facilities (due to high winds, seas, tides), disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, re-routing, unscheduled storage), pumping may be restricted or suspended, pipeline sensor failure likely, possible disruption of construction or maintenance cycles, possible leaks or other pipeline failures, HAZMAT procedures may be initiated, public relations impacts, safety of personnel and equipment (monitoring of crews and equipment required; accidents are likely with possible injury or death)

Hurricane with Winds, High Sea State, Tidal Surge, or Flooding 

Any Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Fuel Barge Operations : docking, fuel movement.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Acquire seas advisories and/obarge operations and off-shormaintenance, or repair. Issue pipeline management and opewill make arrangements with sterminals/customers to accomInitiate fuel management contcancel transfers, etc.) based oConsider the effects of sea-flofailure location for remediation number of visual inspections aefforts. Schedule additional inintegrity. Assign additional crerequired, initiate HAZMAT spiEnsure proper authorities are and footwear for slick and flooshipboard surfaces. Initiate almaintenance work schedule. Check integrity of pipelines, talevel in tanks; sample the liquor fill pipelines to decrease daappropriate.

Earthquakes (any land motion, land slides, avalanches, etc)

Any Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Pipeline roadbed scoured, buried, damaged or destroyed; buried pipeline unearthed, damaged or destroyed; pipeline damage from line stretch and foreign debris impact likely; disruption of fuel delivery resulting in fuel management emergency procedures (re-allocation, transfer delays, re-routing, unscheduled storage); pumping may be restricted or suspended; pipeline sensor failure likely; possible disruption of construction or maintenance cycles; possible leaks or other pipeline failures; HAZMAT procedures may be initiated; public relations impacts; safety of personnel and equipment (Accidents are likely with possible injury or death, monitoring of crews and equipment is required.) 

Issue advisories to pipeline mSchedule additional system madditional crews/re-crews, as management contingency platransfers, etc.) based on impascheduler will make arrangemterminals/customers to accomConsider the effects of topogrlocation for remediation and reof visual inspections and pipeHAZMAT incident occurs, initireaction/mitigation plan. EnsuCheck integrity of pipelines, talevel in tanks; sample the liqu

Atmospheric Transport & Diffusion

Any Control Center Operations : monitor, 

advise, control system integrity.Personnel Safety

Release of vapors and toxins to the environment from a leak or pipeline failure may have catastrophic results, safety of personnel and equipment (Accidents are likely with possible injury or death, monitoring of crews and equipment is required.) 

Acquire output from an (the) amodel depicting the horizontatoxins or vapors. Issue advisomanagement and operators. Ireaction/mitigation plan. EnsuCheck integrity of pipelines, talevel in tanks; sample the liqu

Air Quality (characterization or code)

Poor, red Control Center Operations : monitor, 

advise, control system integrity.Personnel Safety

Safety of personnel and equipment (monitoring of crews and equipment required) 

Issue advisories to pipeline mInitiate alternate construction/Postpone any work that can w

Seafloor pipeline damaged or destroyed; buried pipeline unearthed, damaged or destroyed; pipeline damage from line stretch, foreign debris impact, and corrosion from damaged coating; disruption of fuel delivery resulting in fuel management emergency procedures (reallocation, transfer delays, re-routing, unscheduled storage); pumping may be restricted or suspended; pipeline sensor failure likely; possible disruption of construction or maintenance cycles; possible leaks or other pipeline failures; HAZMAT procedures may be initiated; public relations impacts; safety of personnel and equipment (monitoring of crews and equipment required; accidents are likely with possible injury or death)

Control Center Operations : monitor, advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Fuel Barge Operations : docking, fuel movement.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Tsunami, Tidal Surge Any
Weather Element Threshold Activity Impacts A

Weather Needs for Pipeline System Operations

Space Weather (e.g., solar flares)

Any Control Center Operations : monitor, 

advise, control system integrity.Pumping Station Operations : fuel movement, allocation, storage, distribution.Well-head/Drill Site Operations : pumping, storage, distribution.Tank Farm Operations : storage, distribution, maintenance.Construction: scheduling, maintenance, repair.Hazardous Material: monitoring, mitigation, reclamation, reporting.Surveillance: inspections, monitoring, maintenance.Personnel Safety

Possible disruptions of satellite, radio, and cellular phone communications; communications and data distribution from pipeline sensors may fail during solar storms (Leaks or pipeline failures may be detected without a method to relay the sensed information to the pumping station, tank farm. or control center.); safety of personnel and equipment (monitoring of crews and equipment required); possible disruption of construction or maintenance cycles

Issue advisories to pipeline mReport communication failure solar flares. Monitor communialternative modes of communcontingencies for pipeline sen
Weather Information for Surface Transportation

Appendix B–5

Rural and Urban Transit Systems WIST Needs Template
Weather Information for Surface Transportation

Sector Activities for Rural and Urban Transit Systems

Roadway maintenance. This activity includes roadway surface treatment for snow and ice control

in the winter, as well as maintenance to repair damage to roads and infrastructure.

Bus operations. In addition to bus driving, this activity includes road supervision and maintenance

of the bus fleet, terminals and other facilities, and bus stops.

Trolley bus. This activity refers primarily to electric trolleys with overhead wires.

School transportation. This activity includes transportation of students by bus and commuting to

school by young, inexperienced drivers.

Rail operations. This activity includes passenger rail operations above and below ground, and

station and platform areas. Trains are predominantly electric, using a power rail (“third rail”)

or overhead wires.

Traffic management. Activity consists primarily of managing traffic signals and traffic routing to

enhance safety and efficiency.
Weather Element Threshold Activity Impacts Action 

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane 

obstruction, impaired mobility, road damage, loss of life, property damage, loss of communications/power

Predict threatened area, select treaoperators. Begin preparation procethrough press releases, to ensure pallow adjustment to travel plans.

Operational and travel delays, increased workload, ice treatment requirements 

Prepare, deploy, and track treatmeicing, de-icing treatment chemicalstraffic flow, remove debris, repair d

Increased safety risk, passenger injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/ property, delays in maintenance (facilities, fleet, bus stops) 

Advise operators, implement prepa

(During ice/snow episodes, minor accidents are common for busses, 

snow removal vehicles and equipment. Striking poles, curbs, or fixed objects often results in damage, which can range from $500 to $2500. Source: Rockford, Illinois, Transit.) 

Advise operators to drive with extrerestrict operations (especially on hioperations as appropriate. Advise pradio system. Clear station parking 

Trolley busses Malfunctions due to ice and heavy frost on wires Remove ice from wires, equip track

cutters at start of precipitation.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Safety risk (sliding, braking), collisions, passenger injuries and resulting claims, damage risk 

Advise operators, begin preparatio

Power outages (ice buildup on third rail, catenary lines) Inspect and clear rails, railbeds, caOperational delays (slower operations for safety reasons), increased workload (extra manpower hired), ice on passenger platforms

Restrict or suspend operations, treplatforms and parking lots, activate heaters, remove graded tracks from 

Traffic management Traffic congestion Resequence traffic signals, clear m

Structure Ice Accumulation (inches)

Any Roadway maintenance Safety risk, loss of communications/power, property and structural 

damage

Select treatment strategy, remove 

Roadway maintenance Safety risk, impaired mobility, loss of stability/maneuverability, loss of 

traction, pavement damage, pavement temperature, effects on snow removal/ice treatment operations

Select treatment strategy, remove 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Safety risk to maintenance personnel, motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane obstruction, impaired mobility, road damage, loss of life and property damage 

Predict threatened area, select treaoperators. Begin preparation procecrew planning, shift changes, geogand deployment. Warn the public thto ensure public awareness and alltravel plans.

Operational delays, increased workload, snow accumulation on roadways 

Prepare, deploy, and track treatmeroadway treatment/clearing (sandintreatment chemicals/abrasives, snotraffic flow.

Increased safety risk, passenger injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/ property, delays in maintenance (facilities, fleet, bus stops) 

Advise operators, begin preparatioAdvise operators to drive with extrerestrict operations (especially on hioperations (in some regions). Advisradio system. Clear station parking 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenanceBus operations (road supervision, facility, fleet, bus stop maintenance)

Frozen Precipitation (snow, inches)

Any to <2 inches

Pavement Ice Accumulation (inches)

Any

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Freezing Precipitation (ice) Any Roadway maintenance

Bus operations (road supervision, facility, fleet, bus stop maintenance)Rail operations
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Safety risk (sliding, braking), collisions, passenger injuries and resulting claims, damage risk, power outages (ice buildup on third rail, catenary lines) 

Advise operators, preparation proc

Operational delays, increased workload, snow on passenger platforms

Modify operations, increase manpooperations and maintenance, remopassenger platforms and parking lo

Traffic management Traffic congestion Resequence traffic signals, clear m

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane 

obstruction, impaired mobility, road damage, loss of life, property damage 

Predict threatened area, select treaoperators. Begin preparation procecrew planning, shift changes, geogand deployment. Warn the public thto ensure public awareness and alltravel plans.

Operational delays, increased workload, snow accumulation on roadways 

Prepare, deploy, and track treatmetreatment chemicals/abrasives, plo

flow (implement tire chain controls, designated vehicle types, restrict abridges).

Increased safety risk, passenger injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/ property, delays in maintenance (facilities, fleet, bus stops) 

Advise operators, begin procedureroutes.Advise operators to drive with extrerestrict operations (especially on hioperations (in some regions). Advisradio system. Clear station parking 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Safety risk (sliding, braking), collisions, passenger injuries and resulting claims, damage risk, power outages (ice buildup on third rail, catenary lines), operational delays, increased workload, snow on 

passenger platforms 

Advise operators, begin preparatioInspect and clear rails, railbeds, caoperations, increase manpower for and maintenance, remove snow froplatforms and parking lots.

Run service vehicles or snow trains overhead catenary lines clear. Remtracks from service, use ice scrape

Traffic management Traffic congestion Resequence traffic signals, clear m

Safety risk to maintenance personnel and motorists, travel delays, loss of visibility, loss of traction, loss of stability/maneuverability, lane 

obstruction, impaired mobility, road damage, loss of life, property damage, slope instability (avalanche risk) 

Advise operators. Begin preparatioequipment, crew planning, shift chareassignment and deployment. Wapress releases, to ensure public awadjustments to travel plans.Prepare, deploy, and track treatmesnowfighting operations to treat/cletreatment chemicals/abrasives, plotire chain controls. Manage traffic fdesignated vehicle types, restrict abridges, close roadways and bridge

Frozen Precipitation Roadway maintenance(snow, inches)

> 8 inches

Rail operations

Frozen Precipitation (snow, inches)

> 2 to <8 

inches

Roadway maintenanceBus operations (road supervision, facility, fleet, bus stop maintenance)Rail operations
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Increased safety risk, passenger injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delays in maintenance (facilities, fleet, bus stops) 

Advise operators, preparation procsnow routes.

Put snow routes into effect, advise extreme caution. Modify or restrict on hills), suspend operations as nepassengers via bus radio system. Clots and platforms.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Safety risk (sliding, braking), collisions, passenger injuries and resulting claims, damage risk, power outages (ice buildup on third rail, catenary lines), operational delays, increased workload, snow on 

passenger platforms 

Advise operators, begin preparatioInspect and clear rails, railbeds, caoperations, increase manpower for and maintenance, remove snow froplatforms and parking lots.

Slower train movement, snow buildup on switches and trucks, potential power problems if snow level is above third rail

Run service vehicles or snow trains overhead catenary lines clear. Remtracks from service, use ice scrapecontinuously clear rail switching areand switch heater performance, us

Traffic management Traffic congestion Resequence traffic signals, clear m

Safety risk to maintenance personnel and motorists, travel delays (Winds >15 mph can lead to blowing snow and drifting in some areas. The amount of snow already on the ground may not be the determining factor; if snow storage areas are full, even a few inches can cause drifting problems. Drifting snow can cause continuous and prolonged clearing operations, which strain manpower resources.)

Predict threatened area, consider rConstruct and place living and struBegin equipment preparation, crew changes, geographical reassignmeWarn public through press releases

and allow adjustment to travel plan

Operational delays, increased workload, loss of visibility, loss of traction, lane obstruction, impaired mobility 

Select treatment strategy. Preparetreatment assets. Conduct roadway operations (sanding, plowing, snow tire chain controls, manage traffic fconfiguration.

Increased safety risk, passenger injuries and resulting claims, traffic congestion, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/ property, delays in maintenance (facilities, fleet, bus stops) 

Advise operators, begin preparatioAdvise operators to drive with extrerestrict operations (especially on hioperations (in select areas). Advise radio system. Clear station parking 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Safety risk (sliding, braking), collisions, passenger injuries and resulting claims, damage risk, power outages (ice buildup on third rail, catenary lines), operational delays, increased workload, snow on passenger platforms 

Advise operators, preparation procInspect and clear rails, railbeds, caoperations, increase manpower for and maintenance, remove snow froplatforms and parking lots.

Bus operations (road supervision, facility, fleet, bus stop maintenance)Rail operationsRoadway maintenanceBus operations (road supervision, facility, fleet, bus stop maintenance)Rail operations

Drifting Snow (inches) >6-8 inches
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Slower train movement, snow buildup on switches and trucks, potential power problems if snow level is above third rail

Run service vehicles or snow trains overhead catenary lines clear. Remtracks from service, use ice scrapecontinuously clear rail switching areand switch heater performance, us

Traffic management Traffic congestion Resequence traffic signals, clear mRoadway maintenance Drifting snow, impaired plowing, lane obstruction, loss of stability/ 

maneuverability, loss of traction, pavement temperature effects, slope instability (avalanche risk)

Prepare, deploy, and track treatmetreatment chemicals/abrasives, maremove debris, repair damage.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenance Impaired plowing, lane obstruction Select treatment strategy. School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenance Loss of traction, impaired mobility, effects on snow removal/ice 

treatment operations

Select treatment strategy. 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenance Loss of traction, impaired mobility, effects on snow removal/ice 

treatment operations

Select treatment strategy. 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenance Drifting snow, roadway snow depth Select treatment strategy. School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Snow/Ice Bonding Observation (inches)

Any Roadway maintenance Effects on snow removal/ice treatment operations Select treatment strategy. 

Roadway maintenance Safety risk, maintenance activity delays, public travel delays, loss of 

visibility, loss of traction, loss of stability/maneuverability, lane obstruction /submersion, road damage, treatment chemical dispersion, toxicity and environmental damage 

Predict threatened area, advise opBegin preparation procedures, indu

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Increased safety risk, traffic congestion, vehicle damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delays in maintenance (facilities, fleet, bus stops) 

Begin preparation procedures. 

Operational delays Advise operators of wet road condi

pooling water, drive with extreme coperations.

School transportation Safety risk, vehicle damage risk, schedule delays Advise operators, modify operationRail operations Safety risk, damage risk Advise operators, begin preparatio

Moderate to heavy

Operational delays, potential flood damage to railroad line, bridges, culverts

Modify operations. Inspect railroad culverts.

Any Traffic management Traffic congestion Resequence traffic signals, clear m

Roadway maintenance Safety risks, road submersion, loss of life and property, road 

damage, bridge damage, travel delays

Review contingency plans, issue aBegin preparation procedures.

Maintenance activity delays, traffic slowdowns Begin local mobilization/action and 

travelers. Prepare to monitor/induc

AnyAnyAnyAnyAnyAnyAny

Snow Accumulation Observation (inches)Snow Drift Levels Observation (inches)Roadway Snow Depth Observation (inches)Roadway Snow Pack Depth Observation (inches)Adjacent Snow Depth Observation (inches)Liquid PrecipitationFlooding 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Bus and trackless trolley

operations (road supervision, facility, fleet, bus stop maintenance)

Increased safety risk, traffic congestion, vehicle damage risk, routes may require detours, delays of scheduled operations, traffic accidents, increased risk of damage to busses/property, delays in maintenance (facilities, fleet, bus stops), busses may be called upon to provide evacuation assistance. 

Advise operators, begin preparatio

Operational delays, complete loss of bus service in affected areas, notification of road authorities and public relations required

Advise operators, roadway authoritrelations of real time road conditionsuspend operations. Divert routes aflooding may be occuring or is at hShelter busses on high ground untAssist as requested in civil defense prone areas to safe shelters.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Rail operations Safety risk (trains losing power, evacuations), damage risk 

(trackbed, electrical), operational delays 

Advise operators, begin preparatioadditional manpower for emergencmaintenance. Build dams if necess

Operational delays Modify, restrict, or suspend operatiPower outages (third rail blowouts); flood damage to railroad lines, bridges, culverts

Clear rails and catenary wires. Insplines, bridges, culverts.

Passenger notification requirements Check pumps and drains. Notify pa

address system, public broadcast).

Traffic management Traffic congestion Resequence traffic signals, clear mRoadway maintenance Safety risk, loss of life and property damage, loss of 

communications/ power, maintenance activity delays, travel delays

Cease refueling, restrict or suspend outdoor activities.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, damage risk, operational delays Advise operators, restrict or suspen

NOTE: During thunderstorms, transsuspend operations because of safpassengers waiting at bus stops. 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Rail operations Safety risk (personnel working in train yard or on tracks), damage 

risk (lightning striking switches or electrical boxes causing signal outages), operational delays 

Advise operators, restrict or suspen

Traffic management Traffic congestion, damage to signal operations Monitor/resequence traffic signals. Roadway maintenance Safety risks and travel delays, loss of visibility, loss of traction, 

impaired mobility, lane obstruction, loss of life and property, loss of communications/power

Predict threatened area, prepare to and evacuation plans, advise traverestrict or suspend outdoor activitie

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, damage risk, operational delays Advise operators, restrict or suspen

NOTE: During thunderstorms, transsuspend operations because of safpassengers waiting at bus stops. 

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Rail operations Safety risk, damage risk, operational delays Advise operators, restrict or suspenTraffic management Traffic congestion, damage to signal operations Monitor/resequence traffic signals. Roadway maintenance Safety risks and travel delays, loss of visibility, loss of traction, 

impaired mobility, lane obstruction, loss of life/property, loss of communications/power, maintenance activity delays 

Predict threatened area, advise opreview and implement warning and suspend outdoor operations.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, damage risk, operational delays Advise operators, restrict or suspen

<1/4 inch, < 5-10 miles

Within 20-30 miles

Thunderstorms with <5-10 milesLightning (proximity to route or operational area in miles)

Thunderstorms with Hail (hail size and proximity to route or operational area in miles)Thunderstorms with Tornado (proximity to route or operational area in miles)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Rail operations Safety risk, damage risk, operational delays Advise operators, restrict or suspenTraffic management Traffic congestion Resequence traffic signals, clear m

Roadway maintenance Credibility of evacuation orders, flood risk, property damage, road 

damage loss of visibility, loss of traction, impaired mobility, lane obstruction/submersion, loss of life and property damage, loss of communications/power

Predict threatened area, select treamobilize maintenance personnel, imevacuation plans. Issue evacuation outflow devices, manage traffic flowrepair damage.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Rail operations Safety risk, damage risk, operational delays Advise operators, restrict or suspenTraffic management Traffic congestion Resequence traffic signals, clear m

Major Storms

Roadway maintenance Loss of visibility, loss of traction, impaired mobility, lane 

obstruction/submersion, loss of life, property damage, loss of communications/power 

Predict threatened area, select treaoperators and travelers, suspend oImplement warning and evacuation maintenance forces.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Disruption of scheduled service, disruption of local business operations, schedule delays, increased safety risk, damage to busses and property, scheduled operations modified/restricted/suspended

Advise bus operators, road supervpersonnel. Operate with extreme cpreparation procedures. Modify, reoperations in inundated areas. Cooand other action requirements in suevacuation operations, including evand disabled. Halt all activity on the estimated time of arrival of the leadDeploy all busses and other personevacuation shelters or return them Predict threatened area, select resimplement warning and evacuation operators and travelers, suspend omobilize maintenance forces.Review prediction of threatened arestrategy, update and reissue warniWeather Service issues official hurWeather Service issues official hurwarning. Depending on conditions, begin plaprocedures.

<20 miles 

Within 25-50 miles 

Severe Storm Cell Track—Location, Direction, Speed, Severity (proximity to route or operational area in miles)Blizzard

Loss of visibility, loss of traction, impaired mobility, lane obstruction/submersion, loss of life, property damage, loss of communications/power 

Tropical Cyclone/Hurricane Any within a 

radius of 900 nautical miles

 Roadway maintenance 
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Disruption of scheduled service, disruption of local business operations, schedule delays, increased safety risk, damage to busses and property, operations modified/restricted/suspended

Advise bus operators, road supervpersonnel of pending storm. Operacaution. Begin preparation procedususpend operations in inundated atransportation and other action reqcivil defense evacuation operationsof the elderly and disabled. Halt all minutes prior to estimated time of aleading edge of 40 mph winds. Depother personnel to designated evacreturn them to bus facilities.

General Weather/Environmental ParametersAir Temperature including Maximum and Minimum (degrees F)

Variable, based on impact criteria

Roadway maintenance Air quality, loss of communications/power, precipitation type, 

pavement temperature, slope instability (avalanche risk), effects on snow removal/ice treatment operations

Advise operators, monitor surface operations.

Decrease to less than 32o 

or increase to exceed 32o, 

with moisture

Roadway maintenance Safety and health risk, potential effects on ice/snow removal 

operations, traveler delays

Provide early warning, advise opermonitor surface moisture, begin preApply salt to city streets or conduct actions as appropriate.

<40o Bus operations (road 

supervision, facility, fleet, bus stop maintenance)

Life threat to homeless Transport homeless to shelters. 

<32o with 

moisture 

Bus operations Safety and health risk, passenger injuries and resulting claims, 

potential operational delays 

Advise operators, modify or restrict on hills).

<20 Bus operations Safety and health risk, inoperable vehicles, wayside equipment Issue cold weather alert to operato

implement cold weather plan. NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

<32o with moisture 

School transportation Safety risk, vehicle damage risk, schedule delays Advise operators, modify or restrict 

<32o with moisture 

Rail operations Safety and health risk, passenger injuries and resulting claims, 

potential operational delays 

Advise operators, modify or restrict 

<20o Rail operations Safety and health risk, inoperable vehicles, wayside equipment Issue cold weather alert to operato

implement cold weather plan. NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

<32o with 

moisture 

Traffic management Traffic congestion Resequence traffic signals, clear mRoadway maintenance Health and safety risk, engine/equipment heat stress Advise operators, monitor personn

equipment for signs of heat stress, operations as needed.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Personnel safety, engine/equipment heat stress Advise operators (issue heat alert)

ensure climate control units are op

NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

Rail operations Personnel safety, engine/equipment heat stress Advise operators (issue heat alert)

operations.

>85-95o

Air Temperature Relative to Freezing and Trend (degrees F and rising or falling trend)Air Temperature (degrees F)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Roadway maintenance Personnel safety, heat exhaustion, engine/equipment heat stress Advise operators, monitor personn

equipment for signs of heat stress, operations as needed.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Personnel safety, heat exhaustion, engine/equipment heat stress Modify or restrict operations, ensur

are operating properly.

School transportation Health/safety risk, vehicle damage risk, schedule delays Modify operations, dismiss school eRail operations Personnel safety, heat exhaustion, engine/equipment heat stress Restrict or suspend operations, ens

units are operating properly, reduce 

Dew Point Temperature (degrees F)

Variable, based on temperature and impact criteria

Roadway maintenance Precipitation type, effects on fog formation and air quality, slope 

instability (avalanche risk), effects on snow removal/ice treatment operations

Predict threatened area, select treaoperators, monitor surface moisture

Air Temperature Change Rate (degrees F per 24 hours)

Approx. 60o in 

24 hours

Roadway maintenance Precipitation type, pavement temperature, pavement buckling 

damage due to rapid expansion and contraction

Predict threatened area, select trearoadways.

Time and Air Temp Integrals 

(heating/cooling degree days)

Variable Roadway maintenance Road and property damage risks under extreme heating degree days 

or cooling degree days

Determine stockpile or resources ndamage.

Wet Bulb Temperature (degrees F)

Variable, based on temperature and impact criteria

Roadway maintenance Air temperature, fog dispersal effectiveness Predict threatened area, select trea

disperse fog (cold fog) using CO2 a

Relative Humidity (percent) Variable, 

based on impact criteria

Roadway maintenance Precipitation type, visibililty restrictions Predict threatened area, select trea

Air Stabililty Stable/ 

unstable

Roadway maintenance Air quality (Stable atmosphere inhibits dispersion of pollutants.) Modify operations. 

Subsurface temperature Variable, 

based on contributing factors such as wind, shade, sun

Roadway maintenance Pavement effects (Subsurface temperature affects pavement 

temperature, along with wind, insolation, shade, and other contributing factors.)

Predict threatened area, select trea

>85-90o Roadway maintenance Personnel health and safety, heat exhaustion, engine/equipment 

heat stress, pavement "blow-ups"

Provide early warning, monitor equstress. Modify or restrict maintenanrequired. Take prescribed health aand road repair actions as needed.

<32o but 

>15o, with moisture

Roadway maintenance Safety and health risk, effects on ice/snow removal operations Apply appropriate ice/snow remova

>100-110o

Pavement Temperature (degrees F)Air Temperature (degrees F)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

<15o with moisture

Roadway maintenance Safety and health risk, effects on ice/snow removal operations Because ice removal chemicals ine

abrasives or plow.

Pavement Freeze Point Temperature with Dew Point Temperature (degrees F)

<32o with 

moisture (observation and forecast)

Roadway maintenance Safety risk to maintenance personnel and motorists, loss of traction, 

operational delays, increased workload, anti-icing and de-icing operations required (Applying ice preventative treatment to roadways requires preparation of equipment and crews.) 

Select treatment strategy, advise opreparation procedures for applying liquid chemical tanks or hoppers fohours prior to time for applying treaTreat/clear roadways with anti-icingManage traffic flow.

Pavement Temperature, Moisture Present (degrees F)

>(15-18)o but 

<32o

Roadway maintenance Snow/ice bonding, effects on snow removal/ice treatment operations, 

loss of traction

Predict threatened area, select treaPrepare, deploy, and track treatmetreatment chemicals/abrasives.

<(15-18)o Roadway maintenance Snow/ice bonding, effects on snow removal/ice treatment operations, 

loss of traction, treatment chemical effectiveness

Predict threatened area, select treaPrepare, deploy, and track treatmeapply abrasives.

Pavement Temperature Variable, 

based on impact criteria

Roadway maintenance Snow/ice bonding, effects on snow removal/ice treatment operations, 

loss of traction, treatment chemical effectiveness, melting

Predict threatened area, select treaPrepare, deploy, and track treatmeapply treatment chemicals/abrasive

Roadway maintenance Safety risk, impaired mobility, loss of traction, loss of stability/ 

maneuverability

Predict threatened area, manage tr

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement appropriate 

measures.

Roadway maintenance Safety risk, impaired mobility, loss of traction, loss of stability/ 

maneuverability

Predict threatened area, select treaPrepare, deploy, and track treatmetreatment chemicals/abrasives, plo

flow.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Roadway maintenance Safety risk, impaired mobility, loss of traction, loss of stability/ 

maneuverability

 Predict threatened area, select trea

Prepare, deploy, and track treatmetreatment chemicals/abrasives, ma

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Chemical Concentration (in-road sensor or mobile infrared)

Variable, based on application, residue

Roadway maintenance Safety risk, effects on snow removal/ice treatment operations, 

snow/ice bonding

Select treatment strategy, apply trechemicals/abrasives, deploy and troperate outflow devices.

<1/4 mile Roadway maintenance Safety risk, loss of visibility, impaired mobility Advise operators, modify operation<1/4 mile Bus operations (road 

supervision, facility, fleet, bus stop maintenance)

Safety risk, schedule delays Advise operators, modify operation

<1/4 mile School transportation Safety risk, vehicle damage risk, schedule delays Modify operations, consider/implem

start or early dismissal.

<1/4 to 3 miles

Rail operations Safety risk, schedule delays, difficulty monitoring switch alignment Advise operators, modify operation

<1/4 mile Traffic management Traffic congestion Modify operations. 

Roadway maintenance Safety risk, restricted visibility in glare quadrant of horizon Advise operators, reduce speeds, m

SnowIceAny

Pavement Condition WetVisibility, Including Restricting Conditions such as Fog, Haze, Dust, Smoke (statute miles) Sun Glare
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, restricted visibility in glare quadrant of horizon Advise operators, reduce speeds, m

School transportation Safety risk, vehicle damage risk, schedule delays Advise operators, reduce speeds, mRail operations Safety risk, restricted visibility in glare quadrant of horizon, difficulty 

monitoring switch alignment

Advise operators, reduce speeds, m

Traffic management Safety risk, restricted visibility in glare quadrant of horizon Advise operators, reduce speeds, mRoadway maintenance Safety risk, increased roadway debris, potential operational 

slowdown (Speed and direction are most important when snow has accumulated and drifting results.)

Predict threatened area, select treaoperations, increase debris removasnow drifting is likely, implement eaprocedures, advise travelers, constand structural snow fences for snow 

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Increased safety risk, roadway debris, flying debris, traffic congestion, downed live electric lines and or poles, routes may require detours, increased risk of damage to busses and property, schedule delays, delays of scheduled operations, delays in maintenance (facilities, fleet, bus stops), speed restrictions for express routes

Advise operators when high wind wModify, restrict, or suspend operatineeded. Notify passengers (public 

broadcast).

School transportation Safety risk, vehicle damage risk, schedule delays Advise operators, modify operationRail operations Safety risk; downed live electric lines, catenary wires, and poles; 

schedule delays

Advise operators, modify operationhigh-profile cars.

Traffic management Traffic congestion, potential damage to traffic management systems Monitor traffic management system

>50 mph Roadway maintenance Safety risk, increased roadway debris, operational slowdown (Speed 

and direction are most important when snow has accumulated and drifting results.)

Predict threatened area, select treaoperations, increase debris removasnow drifting is likely, implement eaprocedures, advise travelers, constand structural snow fences for snow 

>50 mph Bus operations (road 

supervision, facility, fleet, bus stop maintenance)

Increased safety risk, roadway debris, flying debris, traffic congestion, downed live electric lines and or poles, increased risk of damage to busses and property, routes may require detours, schedule delays, delays in maintenance (facilities, fleet, bus stops) 

Advise operators when high wind wModify, restrict, or suspend operatirequired. Reschedule delayed opemaintenance.

>50 mph School transportation Safety risk, vehicle damage risk, schedule delays Advise operators, modify or restrict >50 mph Rail operations Safety risk; downed live electric lines, catenary wires, and poles; 

schedule delays

Advise operators, modify or restrict 

>70 mph Service over bridges suspended 

>50 mph Traffic management Traffic congestion, potential damage to management systems Monitor management systems. 

<32o 

with moisture

Rail operations Potential safety risk, damage to track Inspect tracks, modify operations. 

> 85-130o Rail operations Heath and safety risk, equipment heat stress, sagging catenary 

wires, potential for track damage (heat kink in rails) 

Advise operators, modify or restrict rails while hot, reduce speed of tra

Roadway maintenance Safety and health risk (hypothermia, frost bite) Advise operators, restrict or suspen

necessary.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety and health risk (hypothermia, frost bite) Advise operators, modify operation

NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

School transportation Safety and health risk (hypothermia, frost bite) Modify operations. If necessary, se

response strategy, e.g., 2-hour delaearly dismissal.

>30 mph but <50 mph<20o 

Wind: Head, Cross, or Tail, including Convective Winds 

(wind speed in miles per hour)Rail Temperature (degrees F)Wind Chill (degrees F)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Rail operations Safety and health risk (hypothermia, frost bite), frozen 

switches/vehicles/equipment

 Advise operators, rotate personnel 

modify operations. Exercise switchdoors and equipment while not in u

Roadway maintenance Safety and health risk (heat exhaustion) Advise operators, restrict or suspenBus operations (road supervision, facility, fleet, bus stop maintenance)

Safety and health risk (heat exhaustion) Advise operators, modify operation

NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

School transportation Health and safety risk, vehicle damage risk, schedule delays Modify operations. Dismiss school Rail operations Safety and health risk (heat exhaustion) Advise operators, modify operation

NOTE: During extreme temperaturnormally not suspend operations bconcerns for passengers waiting at 

Roadway maintenance Potential health and safety risk Advise operators, modify or restrict Bus operations (road supervision, facility, fleet, bus stop maintenance)

Potential health and safety risk Reschedule, increase passenger c

School transportation Potential health and safety risk Reschedule, increase passenger cRail operations Potential health and safety risk Reschedule, increase passenger cTraffic management Traffic congestion Advise motorists to take mass tranRoadway maintenance Radio/cellular phone communication disruptions Advise operators, monitor communBus operations (road supervision, facility, fleet, bus stop maintenance)

Radio/cellular phone communication disruptions Advise all operators, road supervis

the bus radio system of temporary communications.

School transportation Radio/cellular phone communication disruptions Advise operators, monitor communRail operations Radio/cellular phone communication disruptions Advise operators, monitor commun

place communications personnel odisruptions.

Traffic management Potential impact on traffic management systems Monitor traffic management system

Total Sun (insolation per 24 hours)

Total per 24 hour period

Roadway maintenance Air temperature, pavement temperature, toxicity and environmental 

damage 

Modify operations as necessary. 

Cloud Cover Forecast Scattered, 

broken, overcast

Roadway maintenance Air temperature, pavement temperature, toxicity and environmental 

damage 

Modify operations as necessary. 

Water Course Flow Volume (cubic meters per second)

Variable, based on flood stage criteria

Roadway maintenance Flood risk, lane submersion, loss of life and property, road damage Predict threatened area, select trea

operate outflow devices, develop wplans.

Water Body Depth (feet) Variable, 

based on flood stage criteria

Roadway maintenance Flood risk, lane submersion, loss of life and property, road damage Predict threatened area, select trea

operate outflow devices, develop wplans.

Any>100-105o

Poor/code red

Heat Index (degrees F)Air QualitySpace Weather (e.g., solar flares)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Any Roadway maintenance Safety risk, damage to vehicles, road damage, evacuation route 

delays

Predict threatened area, repair dam

>5 feet Bus operations (road 

supervision, facility, fleet, bus stop maintenance)

Increased safety risk, damage to busses, delays to scheduled operations or complete disruption of service on routes through coastal areas 

 Advise operators and road supervconditions, request radio reports of crossing the highway. Modify, restroperations. 

>8 feet Roadway maintenance Safety risk, damage to vehicles, road damage, evacuation route 

delays

Predict threatened area, repair dam

18-20 feet Bus operations Increased safety risk, damage to busses, delays to scheduled 

operations or complete disruption of service on routes through coastal areas 

 Advise operators and road supervconditions, request radio reports of crossing the highway. Modify, restroperations. As requested, assist Cevacuation of coastal areas to safe 

Roadway maintenance Impaired mobility, loss of life and property, lane obstruction, effects 

on snow removal/ice treatment operations

Close roadways, release avalanche

operations as necessary.

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Bus operations Bus routes and service likely impacted due to blocked roads, 

possible requests to provide evacuation assistance

Modify routes as required, be prepaassiatance. 

Roadway maintenance Road damage, property damage, impaired mobility, loss of life and 

property

Manage traffic flow, modify operatiorepair damage.

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, damage to buses and property, potential for tsunami in coastal areas, disrupted operations, operations modified/restricted/ suspended 

Conduct immediate, spontaneous, If communications are still up, adviroll of operators and supervisors. Adepartment, civil defense, and the 

School transportation Safety risk, vehicle damage risk, schedule delays Select response strategy, e.g., sch

closure, or early dismissal.

Tsunami (Japanese for "wave in the harbor")

Any alert or warning from the Pacific Tsunami Warning Center

Bus operations (road supervision, facility, fleet, bus stop maintenance)

Safety risk, disrupted operations, service delays, damage to equipment, operations modified/restricted/suspended 

Advise operators and road supervisprocedures. Modify, restrict, or susinundated areas. Coordinate transpaction requirements in support of coperations, including evacuation of disabled. As situation and time perendangered residents/visitors from areas to designated tsunami evacuTerminate service 45 minutes prior of arrival of the tsunami wave.

High, moderate, lowAny seismic activity

Storm Surge (height above mean high tide, in feet)High Surf (wave height in feet)Avalanche Danger Seismic Activity (earthquakes)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Rural and Urban Transit System (Local Roads and Light Railway) Operation

Roadway maintenance Road damage, property damage, impaired mobility, loss of life and 

property, air quality

Manage traffic flow, modify operatio

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Soil moisture Saturated, 

unsaturated

Road maintenance Flood risk, road and pavement damage, effects on pavement 

condition

Select treatment strategy. 

Roadway maintenance Loss of visibility, loss of life and property, air quality Manage traffic flow (e.g., close roa

School transportation Safety risk, vehicle damage risk, schedule delays Select and implement response str

delay, school closure, early dismiss

Fair Weather 1 to 10 Days Roadway maintenance Operational planning (The tasks that will be undertaken in periods of 

good weather depend somewhat on how much good weather is anticipated. Crews work year round; there are no reserves or parttime personnel to call in for snow or other severe weather events. Details of crew assignments vary day to day, some days plowing and sanding, some days working on drainage, some days on signs and guardrail, etc. A certain amount of mobilization is required for some tasks.)

Examples: (1) Ditching requires remmounting a truck box, and replacinattachment on a loader with a buckprobably take 2 days. Such actions without a forecast of 10 days of goobecause of the time needed to reco(2) In urban areas, snow hauling is storm. The same amount of work is after a 6-inch fall as a 12-inch one. forecast following a 6" snow event, started. If another snow event is fodays, hauling may be delayed. (3) weather, as well as bad, aid manag

efficiently.

Roadway maintenance Severe threat to life, health and safety risk, dispersion of extremely 

dangerous hazardous materials, agents, substances

Close/detour roadways, assist in Aand Diffusion and HAZMAT responneeded.

School transportation Severe threat to life, health and safety risk, dispersion of extremely 

dangerous hazardous materials, agents, substances

 Select and implement response str

delay, school closure, early dismiss

Any fire event 

or activityAnyAny volcanic activity

Volcanism Fire Nuclear, Biological, or Chemical Release 
Weather Information for Surface Transportation

Appendix B–6

Airport Ground Operations WIST Needs Template
Weather Information for Surface Transportation

Sector Activities for Airport Ground Operations

Aircraft movement. Includes all ground movement of aircraft and safety of flight considerations

that affect aircraft ground movement.

Vehicle movement. Vehicle movement and traffic flow on the airfield and on approaches to the

airfield

Gate accessibility. Includes operations for the transfer of baggage and cargo and general aircraft

servicing (cleaning, catering, minor maintenance) while an aircraft is parked at a gate.

Aircraft maintenance. All ground maintenance conducted away from the gate.

Refueling aircraft. Includes transportation of fuels from at-airport storage to aircraft and the

operations during transfer from fuel truck to aircraft fuel tanks.

Foot traffic. All pedestrian movement on the airfield.

Construction and maintenance projects. All vehicular movement and operations related to

construction or structural maintenance of airport and airfield facilities, while the airport continues

to operate.
Weather Element Threshold Activity Impacts Action 

Conduct early planning to ensure avaiequipment and supplies (stockpile of sparking areas, other materials for runwmanpower availability. Advise carriersall tenants. Prepare de-icing pads for euse a 24-30 hour forecast for a prelimiImplement personnel recall, go to 12-hof application (anti-ice, sand, etc.). Airschedule changes and plan reconstituupdates) to all airport tenants. Execute airlines could begin de-icing aircraft at snow plan. Form the snow desk/snow NOTAMS, track expected storm duratiand update advisories and plan activittreating runways, taxiways, roads, parMonitor pavement subsurface and surcontinued snow removal strategy. Alewhite-out conditions. Conduct early planning for availability/supplies (stockpile of anti-ice and de-icavailability, ready designated aircraft dFixed Base Operator, and all tenants. Implement personnel recall, go to 12-hhour shifts is driven by manpower avaanti-ice/de-ice application material, anto derive the greatest benefit/effectivenAirlines could implement flight schedureconstitution. Issue advisories (and usnow and ice control plan(s) (with tem

high humidity, airlines could begin de-NOTAMS, track storm onset and experunways, taxiways, roads, parking areapavement subsurface and surface temremove freezing precipitation. Airline meteorology/operations/dispatcmanagers of potential threat. Station d"iceman," plans for availability/readineand manpower. Airport operations alericing pads for expected use. Airport coto tenants on type of precipitation expeand duration, temperature, and wind. Use the latest forecast (type and rate otemperature) to select the de-icing maeffectiveness. (Airlines may implemenadditional function of de-icing in turninde-icing fluid before precipitation beginprecipitation from bonding (freezing) to roll, the accumulated precipitation slidecan be applied to remove frozen preciFrost and "cold wing" icing are routineprecipitation is not present. Note: If rate of freezing precipitation is current observation, operations will like

Weather Needs for Airport Ground Operations

Frozen Precipitation (snow, inches) 

>1/2 inch per hour

Aircraft movement, vehicle movement, gate accessibility, foot traffic, aircraft maintenance 

Personnel safety risk, equipment damage risk, operational delays and cancellations, potential runway closure (biggest impact on intersecting runways), parking limitations, airport access road conditions (Heavy snow coupled with high winds will cause blizzard conditions and "white-outs." All snow removal ceases until visibility improves.)

Freezing Precipitation (all ice forms) 

Any Aircraft movement, vehicle 

movement, gate accessibility, foot traffic, aircraft maintenance

Personnel safety risk, equipment damage risk, operational delays/cancellations, potential runway closure, airport parking limitations, decreased traction/maneuverability on airport access roads 

Freezing Precipitation (ice, inches) *Note: This section treats aircraft deicing as responsibility of the airline/ pilot-in-command. 

Any Safety of flight Safety risk, equipment damage risk, schedule delays and cancellations 

(Frozen precipitation of any kind, along with frost and rime icing picked up on descent, affects the aerodynamic performance features of an aircraft. Lift is dramatically affected and is most critical on take-off/climb-out. "Holdover-time," the maximum allowable time between the start of de-icing and actual take-off, varies with the weather conditions and the type of de-icing fluid used. The proper selection must be made for effectiveness, efficiency, and above all, safety. Efficient de-icing operations minimize schedule impacts.)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Airport Ground Operations

Airlines advise station managers of imairport operations advises all tenants. and maintenance projects.Continue issuing advisories to all airfieof construction equipment. Hangar or tin use or not needed in short term. Mogrid. Begin shutting down noncritical aobserved at or near outer boundaries oHalt all refueling when lightning is obseof the airfield, get personnel inside and Note: Some operators pull their persolightning is observed at or within 10 naAirlines advise station managers of imoperations advises all tenants. Plan opmaintenance projects.Continue issuing advisories to all airfieconstruction equipment. Hangar or tie-use or not needed in short term. Begin activities when hail is observed within airfield. Hangar aircraft. When hail is observed within 3 nauticarefueling. Get personnel inside and unNote: Some operators pull their peoplobserved at or within 10 nautical miles Advise construction contractor and mawinds. Examine options for constructioAdvise all airfield tenants, advise air trfrequent ramp, taxiway, and runway ineliminate foreign object damage).If de-icing of aircraft is required, decide done, to control blowing spray. Select operation. Continue advisories to tenataxiway, and runway inspections. Ensucontainers, baggage, etc., that are not chocked for the duration of high windsareas frequently for foreign objects (to damage). Store equipment that is not Training for dealing with extremely colSeptember. Assure all personnel are eclothing and other cold weather gear wway radios, cell phones, foot and hand alert station managers, airports alert aand what kind of construction/repair mschedule. Use easy-to-follow checklistsafety detail is overlooked.Limit personnel time outside to periods available manpower to account for timmust take warm-up breaks inside. Insiwork with appropriate cold weather attground crew with warm fluids (tea, cofwarm up and avoid dehydration. 

Thunderstorms with Lightning, including Microburst Event

Within 3, 5, 17 nautical miles of the airfield

Refueling aircraft, construction and maintenance projects, general aircraft servicing (cleaning, catering, minor maintenance), baggage/cargo transfer 

Personnel safety risk, equipment damage risk, operational delays/cancellations, summer construction projects delayed, airfield maintenance projects delayed, aircraft servicing (refueling, maintenance) delayed

Thunderstorms with Hail Within 5 

nautical miles of airfield

Refueling aircraft, construction and maintenance projects, general aircraft servicing (cleaning, catering, minor maintenance), baggage/cargo transfer

Personnel safety risk, equipment damage risk, operational delays/cancellations, summer construction projects delayed, aircraft servicing (refueling, maintenance) delayed (Hail greater than 1 inch can severely damage aircraft not in flight.) 

Wind Speed and Direction, including Microburst Event (knots) 

>25-35 knots Construction projects, 

aircraft movement, aircraft servicing (cleaning, catering), baggage/cargo transfer 

Construction materials blow loose, increased incidence of foreign objects present in aircraft movement areas, maintenance at high locations on large aircraft impeded/slowed, delays in turning aircraft and runway changes contribute to schedule delays, snow removal and de-icing operations affected (Crosswind factors and dramatic wind shifts affect choice of runway. Runway changes at busy times contribute to schedule delays. Snow blower and aircraft de-icing operations must consider wind direction and speed. Blowing dust from construction sites presents a hazard.)

Temperature and Chill Factor (degrees F) (counts as 2 weather elements)

<0o F (with or 

without wind) or wind chill factor of <-20o F

Construction projects, aircraft servicing (cleaning, catering, minor maintenance), baggage and cargo transfer, routine refueling 

Personnel exposure (hypothermia, frost bite), water onboard aircraft may freeze during routine servicing, minor delays in turning aircraft because servicing personnel are limited in time they can spend outside, personnel safety procedures strictly enforced (buddy system required, time outside is limited and actively managed)
Weather Element Threshold Activity Impacts Action 

Weather Needs for Airport Ground Operations

Issue an advisory to all airlines and all vehicular traffic flow to bypass known coordinate with other agencies in the vcontrol points. Prepare equipment for sstanding water. Plan to have adequate personnel available Prepare to execute the plan for heavy Coordinate with construction contractoIssue advisory to all airport tenants. Enare available for service.Coordinate with air traffic control. At soRunway Visual Range reaches 600 ft, Ensure that "Follow me" guidance veh

Heavy Rain >1-2 inches per 

hour (produces standing water on tarmac)

Construction projects, aircraft movement, aircraft servicing, vehicle/traffic flow on airfield and approach to the airfield 

Construction projects impeded, slowing of all vehicular movement on the airfield (both on the ramp and on access roads/parking areas), foot traffic impeded, safety risk for employees and passengers, schedule delays possible

Visibility: Any Obstruction to Vision, Primarily Fog (statute miles) 

<1/4 mile Construction projects 

(many at night, at non-peak air traffic hours, but at peak fog occurrence times), aircraft movement, vehicular movement 

Potential delays to completion of construction and repair projects; increased probability for incursion incidents; all aircraft and vehicular movement slowed, with attendant schedule delays
Weather Information for Surface Transportation

C - 1

Appendix C

Abbreviations and Acronyms Listing
Weather Information for Surface Transportation

C - 2

Abbreviations and Acronyms Listing

AAR Association of American Railroads

AFWA Air Force Weather Agency

API American Petroleum Institute

ATIS Advanced Traveler Information System

ATWIS Advanced Transportation Weather Information System

DOC U.S. Department of Commerce

DoD U.S. Department of Defense

DOI U.S. Department of the Interior

DOT U.S. Department of Transportation

EPA U.S. Environmental Protection Agency

ESS Environmental Sensor Station

FAA Federal Aviation Administration

FCMSSR Federal Committee for Meteorological Services and Supporting Research

FEMA Federal Emergency Management Agency

FHWA Federal Highway Administration

GDP Gross Domestic Product

GPS Global Positioning System

HAZMAT Hazardous material(s)

ICMSSR Interdepartmental Committee for Meteorological Services and Supporting

Research

ISTEA Intermodal Surface Transportation and Efficiency Act

ITS Intelligent Transportation System

MADIS Meteorological Assimilation Data Ingest System

MTS U. S. Marine Transportation System

NASA National Aeronautics and Space Administration

NHTSA National Highway Traffic Safety Administration

NOAA National Oceanic and Atmospheric Administration

NOTAM Notice to Airmen

NRC Nuclear Regulatory Commission

NTP National Transportation Program [of the Department of Energy]

NWS National Weather Service

OFCM Office of the Federal Coordinator for Meteorological Services and

Supporting Research

OPS Office of Pipeline Safety

PMA Power Marketing Administration

R&D Research and Development

RSPA Research and Special Programs Administration

RWMP Road Weather Maintenance Program

USDA U.S. Department of Agriculture

USGS U.S. Geological Survey/Service

USTRANSCOM U.S. Transportation Command

WIST Weather Information for Surface Transportation
Weather Information for Surface Transportation

D - 1

Appendix D

 Glossary of Terms
Weather Information for Surface Transportation

D-2

Glossary of Terms

Weather Element(s) Definition

A

Adjacent Snow Depth The actual depth of snow on areas other than the surface of roadway

pavement, drifts and plowed areas. (FHWA)

Air Quality The AQI is an index for reporting daily air quality. It indicates how

clean or polluted the air is, and the associated health concerns. The

AQI focuses on health effects that can happen within a few hours or

days after breathing polluted air. EPA uses the AQI for five major

air pollutants regulated by the Clean Air Act: ground-level ozone,

particulate matter, carbon monoxide, sulfur dioxide, and nitrogen

dioxide. For each of these pollutants, EPA has established national

air quality standards to protect against harmful health effects. (EPA

webpage)

GREEN: “Good” The AQI value for your community is between 0

and 50. Air quality is considered satisfactory and air pollution poses

little or no risk.

YELLOW: “Moderate” The AQI for your community is between 51

and 100. Air quality is acceptable; however, for some pollutants

there may be a moderate health concern for a very small number of

individuals. For example, people who are unusually sensitive to

ozone may experience respiratory symptoms.

ORANGE: “Unhealthy for Sensitive Groups” Certain groups of

people are particularly sensitive to the harmful effects of certain air

pollutants. This means they are likely to be affected at lower levels

than the general public. For example, children and adults who are

active outdoors and people with respiratory disease are at greater

risk from exposure to ozone, while people with heart disease are at

greater risk from carbon monoxide. Some people may be sensitive to

more than one pollutant. When AQI values are between 101 and

150, members of sensitive groups may experience health effects.

The general public is not likely to be affected when the AQI is in

this range.

RED: “Unhealthy” AQI values are between 151 and 200. Everyone

may begin to experience health effects. Members of sensitive groups

may experience more serious health effects.

PURPLE: “Very Unhealthy” AQI values between 201 and 300

trigger a health alert, meaning everyone may experience more

serious health effects.

MAROON: “Hazardous” AQI values over 300 trigger health

warnings of emergency conditions. The entire population is more

likely to be affected.
Weather Information for Surface Transportation

D-3

Weather Element(s) Definition

Air Stability For the purposes of this report, air stability describes the tendency

for air to rise or to be restricted from rising, normally described as

stable or unstable. An unstable atmosphere is generally associated

with convection and the potential for showers, thunderstorms. A

stable atmosphere is generally associated with low clouds, fog, poor

visibilities, and poor air quality.

Air Temperature The degree of hotness or coldness of the air measured on a

temperature scale by means of a thermometer. (AMS glossary

derived)

Air Temperature Change Rate For the purposes of this report, the change in temperature at a given

location during a specified period of time, e.g. 6, 12, or 24 hours.

Atmospheric Transport &

Diffusion

For the purposes of this report, the transportation and diffusion of

toxic substances by atmospheric movement and turbulent processes.

Avalanche A mass of snow (perhaps containing ice and rocks) moving rapidly

down a steep mountain slope. (AMS Glossary)

B

Blizzard A severe weather condition characterized by temperatures near or

below 10 degrees Fahrenheit, winds 32 mph or higher, and snow

(mostly fine, dry snow picked up from the ground) reducing

visibility to less than 500 feet. (AMS Glossary)

C

Chemical Concentration For the purposes of this report, the residual concentration of

chemicals on the road surface as the result of the most recent

application of treatment chemicals or substances.

Cloud Cover That portion of the sky cover which is attributed to clouds. (AMS

Glossary derived)

Scattered: Description of a sky cover 1/8 to 4/8, applied only when

clouds or obscuring phenomena aloft are present.

Broken: Description of a sky cover of 5/8 to 7/8, applied only when

clouds or obscuring phenomena aloft are present.

Overcast: Description of a sky cover of 8/8, when at least a portion

of this amount is attributable to clouds or obscuring phenomena

aloft.

D

Dew Point Temperature The temperature at which a given parcel of air must be cooled at

constant pressure and constant water-vapor content in order for
Weather Information for Surface Transportation

D-4

Weather Element(s) Definition

saturation to occur. (AMS Glossary)

Drifting Snow Snow raised from the surface of the earth by the wind to a height of

less than six feet above the surface. When snow is raised to six feet

or more above the surface, it is classified as blowing snow. Snow

Drift: Snow deposited behind obstacles or irregularities of the

surface, or collected in heaps by eddies in the wind. (AMS Glossary)

F

Fair Weather When this term is used in weather forecasts, it is meant to imply no

precipitation, less than 3/8 sky cover of low clouds, and no other

extreme conditions of cloudiness, visibility, or wind. (AMS

Glossary derived)

Fire For the purposes of this report, any fire event at or near areas of

transportation operations. This includes the threat caused by the

actual flames, fire induced winds, and visibility restrictions caused

by smoke.

Flooding The condition that occurs when water overflows the natural or

artificial confines of a stream or other body of water, or accumulates

by drainage over low-lying areas. (AMS Glossary)

Freezing Precipitation Any form of liquid precipitation that freezes upon impact with the

ground or exposed objects; i.e., freezing rain, or freezing drizzle.

(AMS Glossary)

Freezing Spray Sea spray transported through the air that freezes on ship’s surfaces

and structures.

Frozen Precipitation Any form of precipitation that reaches the ground in frozen form; i.e.

snow, snow pellets, snow grains, ice crystals, ice pellets, and hail.

(AMS Glossary)

G

Glare Any hindrance to vision caused by scattering or reflection of light

into an observer's line of sight. (AMS Glossary)

H

Hail Precipitation in the form of balls or irregular lumps of ice, always

produced by convective clouds, nearly always cumulonimbus. (AMS

Glossary)
Weather Information for Surface Transportation

D-5

Weather Element(s) Definition

Heat Index For the purposes of this report, sometimes referred to as the

"apparent temperature" and given in degrees Fahrenheit. Heat Index

is an accurate measure of how hot it really feels when the relative

humidity (RH) is added to the actual air temperature. 

High Surf Surf: The sea-surface wave activity between the outermost line of

breakers and the shore. (AMS Glossary) For the purposes of this

report, high surf thresholds are variable depending on specific

transportation activities, operations, and the vulnerability of roadway

operations to surf damage.

High Winds For the purposes of this report, any wind speed (normally in excess

of 25 mph) that impacts normal or unique operations or activities.

Hurricane (Tropical Cyclone) One of the most intense and feared storms of the world with winds

of 74 mph or higher and torrential rains. (AMS Glossary)

I

Ice Gorging The stacking and packing of ice due to river currents and river

constrictions. Ice often packs all the way to the river bottom.

Inland Waterway Ice Coverage Percentage of rivers, bays, lakes, and inter-coastal waterways

covered by surface ice.

L

Lightning Generally any or all of the various forms of visible electrical

discharge produced by thunderstorms. (AMS Glossary)

Liquid Precipitation Liquid water droplets that fall from the atmosphere and reach the

ground. Liquid precipitation includes drizzle and rain. (AMS

Glossary derived)

N

Nuclear, Biological, or

Chemical Release

For the purposes of this report, any release of nuclear, biological, or

chemical substances onto the surface or into the atmosphere or

waterways.

Open Water Sea Ice Ice formed by the freezing of seawater. Forming first as lolly ice

(frazil crystals), thickens into sludge, and coagulates into sheet ice,

pancake ice, or into floes of various shapes and sizes. (AMS

Glossary)

P

Pavement Condition The state of the surface of roadway pavement based on current or
Weather Information for Surface Transportation

D-6

Weather Element(s) Definition

recent weather conditions, road conditions, and traffic conditions.

The pavement conditions are expressed as dry, wet, snow/slush and

ice. (FHWA)

Pavement Freeze Point

Temperature

The temperature at which the existing solution on the roadway will

freeze. The critical temperature varies because the normal freeze

point of water can be depressed by dissolved chemicals. (FHWA)

Pavement Ice Accumulation The actual depth of ice on the surface of roadway pavement.

(FHWA)

Pavement Temperature The temperature of the surface of roadway pavement based on

thermal energy flows to and from the subsurface (conduction), to

and from the air (boundary layer conduction, convection and

radiation), water phase changes at the surface (energy from

condensation, energy to evaporation), radiation from the sun or

surrounding objects that reflect solar energy, and terrestrial heat

transfers, e.g. vehicles. (FHWA)

Precipitable Water Vapor The total atmospheric water vapor contained in a vertical column of

unit cross-sectional area extending between any two specified levels

of the atmosphere. (AMS Glossary)

R

Rail Temperature The temperature of the surface of the rail based on thermal energy

flows to and from the subsurface (conduction), to and from the air

(conduction, convection and radiation), water phase changes at the

surface (energy from condensation, energy to evaporation), radiation

from the sun or surrounding objects that reflect solar energy, and

terrestrial heat transfers, e.g. vehicles.

Relative Humidity The (dimensionless) ratio of the actual vapor pressure of the air to

the saturation vapor pressure . (AMS Glossary)

River/Lake Ice Ice formed on the surface of a river/lake. (AMS Glossary)

Roadway Snow Depth The actual depth of unpacked snow on the surface of roadway

pavement. (FHWA)

Roadway Snow Pack Depth The actual depth of packed snow on the surface of roadway

pavement. (FHWA)
Weather Information for Surface Transportation

D-7

Weather Element(s) Definition

S

Seismic Activity

(earthquakes)

For the purposes of this report: Any earthquakes or earth tremors.

Snow Accumulation

(also called snow depth)

The actual depth of snow on the ground at any instant during the

storm, or after any single snowstorm or series of storms. (AMS

Glossary)

Snow Drift Levels For the purposes of this report, the height of the crest of snowdrifts

(see drifting snow above) measured in inches or feet.

Snow/Ice Bonding The formation of a bonding layer of ice beneath snow accumulated

on the surface of roadway pavement. (FHWA)

Soil Temperature The temperature of the soil below the rail or roadway surface (same

as subsurface temperature).

Soil Moisture Moisture in the soil within the zone of aeration, including water

vapor (also part of the soil air) present in the soil pores. In some

cases this refers strictly to moisture within the root zone of plants.

(AMS Glossary)

Space Weather Space Weather refers to conditions on the sun and with the solar

wind, magnetosphere, ionosphere, and the thermosphere that can

influence the performance and reliability of space-borne and groundbased technological systems and can endanger human life or health.

Adverse conditions in the space environment can cause disruption of

satellite operations, communications, navigation, and electric power

distribution grids, leading to a variety of socioeconomic losses.

(National Space Weather Program, Strategic Plan)

Storm Cell Track For the purposes of this report, the path of past locations, present

location, direction of movement, speed of movement, and intensity

of storm cells as indicated by a storm detection radar.

Storm Surge An abnormal rise of the sea along the shore as the result, primarily,

of the winds of a storm. (AMS Glossary)

Structure Ice Accumulation The actual depth of ice on roadway structures. (FHWA)

Subsurface Temperature The temperature of the soil below the surface. (FHWA)
Weather Information for Surface Transportation

D-8

Weather Element(s) Definition

T

Time and Air Temp Integrals

(heating/cooling degree days)

Degree day: Generally, a measure of the departure of the mean daily

temperature from a given standard: one degree day for each degree

(C or F) of departure above (or below) the standard during one day.

(AMS Glossary)

Tornado or Waterspout A violently rotating column of air, pendant from a cumulonimbus

cloud, and nearly always observable as a "funnel cloud" or tuba. On

a local scale, it is the most destructive of all atmospheric

phenomena. (AMS Glossary)

Total Sun (Insolation) Insolation (incoming solar radiation). In general, solar radiation

received at the earth's surface. (AMS Glossary)

Tropical Storm Force Winds Winds equal to or greater than 39 mph but less than 74 mph.

Tsunami Japanese for "wave in the harbor" (also called a seismic sea wave or

tidal wave). An ocean wave produced by a submarine earthquake,

landslide or volcanic eruption. These waves may reach enormous

dimensions and have sufficient energy to travel across entire oceans.

(AMS Glossary)

V

Visibility In United States weather observing practice, the greatest distance in

a given direction at which it is just possible to see and identify with

the unaided eye (a) in the daytime, a prominent dark object against

the sky at the horizon, and (b) at night, a known, preferably

unfocused, moderately intense light source. After visibilities have

been determined around the entire horizon circle, they are resolved

into a single value of prevailing visibility for reporting purposes.

(AMS Glossary)

Volcanism For the purposes of this report, any volcanic activity e.g. eruptions,

earthquakes, ashfall which can impact transportation operations and

activities.

W

Water body depths The measured depth of a water body, e.g. river or stream, from a

specified datum at a specified location. (FHWA)

Water course flow volume Volume of water that passes a given point within a given period of

time. (FHWA)
Weather Information for Surface Transportation

D-9

Weather Element(s) Definition

Water Temperature The measure of the surface/near surface temperature of the water as

measured by a thermometer. (AMS Glossary)

Wet Bulb Temperature The temperature an air parcel would have if cooled to saturation.

(AMS Glossary)

Wind Chill That part of the total cooling of the body caused by air motion.

(AMS Glossary)

Wind Direction The direction from which the wind is blowing. (AMS Glossary)

Headwind: A wind that opposes the intended progress of an

exposed, moving object.

Tailwind: A wind which assists the intended progress of an

exposed, moving object.

Crosswind: A wind which has a component which is directed

perpendicularly to the course (or heading) of an exposed, moving

object.

Wind Direction (upper air) Upper Air: That portion of the atmosphere which is above the lower

troposphere. No distinct lower limit is set but the term is generally

applied to the levels above 5 thousand feet (850mb). (AMS

Glossary derived)

Wind Speed The velocity of air in motion relative to the surface of the earth.

(AMS Glossary derived)

Wind Wave Height Height of the ocean surface wave generated by the wind. (AMS

Glossary derived)
Weather Information for Surface Transportation

E-1

Appendix E

Weather Research and Technology Development

Required to Meet WIST User Needs
Weather Information for Surface Transportation

E-2

Weather Research and Technology Development

Required to Meet WIST User Needs

This list was compiled from information provided by agencies supporting research and

application development specific to WIST user needs (e.g., FHWA), leaders in the

surface transportation research community (e.g., University Corporation for Atmospheric

Research, National Center for Atmospheric Research), and the representatives of WIST

user communities who participated in the meetings and symposia held for this study.

Based on the information received and general knowledge of the state of R&D in specific

areas, OFCM staff have estimated when R&D results can be anticipated for each item

listed. An NT (near term results) after an item indicates that substantial work already in

progress or a directed development effort can probably produce significant impact for

WIST users within five years (end of fiscal year 2007). An FT (far term results) indicates

that gaps in the knowledge base require more extensive research to support useful

applications, with impacts for WIST users anticipated after 2007. In many instances, an

R&D item is likely to have useful, but limited, real impact in the near term, with more

extensive impacts on WIST user needs requiring more time. These items are marked with

both the NT and FT flags.

I. Requirements for Incorporating Observed Fine-Scale Weather and Related

Elements into WIST Applications

A. Weather elements and related phenomena that can be observed and predicted with

existing methods but require integration into operational roadway transportation

information systems. NT

1. Black ice on roadways (demonstrated in the Meridian SAFE ATIS program).

NT

2. Turbulent vortices around large vehicles (demonstrated in the Meridian SAFE

ATIS program). NT

3. Sun glint and glare (demonstrated in the Meridian SAFE ATIS program). NT

B. Weather elements and consequences that can be observed with existing

technology as point measurements but require spatial distribution modeling for

surface transportation applications. NT

1. Frost heave of road surfaces and its impact on load-bearing capacity of roads

and railbeds. (FHWA research underway at University of North Dakota). NT

2. Spatial distribution of pavement conditions (temperature, frost, ice, etc.)

beyond the point measurements available with roadway monitoring sites

(RWIS). NT, FT

3. Rainfall spatial variability leading to hydroplaning and other local flooding

hazards. NT
Weather Information for Surface Transportation

E-3

C. Increase access to the Continuously Operating Reference System, which enables

highly accurate height and position measurements using GPS for applications in

waterways and other surface transportation uses. NT

II. Prediction of Roadway and Railway Condition

The existing technologies for predicting road or rail condition are still primitive. Most of

the best current prediction systems use two-dimensional heat transfer equations

parameterized in very simple ways to account for cloud cover, total insolation,

precipitation, and other weather factors. New methods uncovered by research in this area

could significantly advance predictive capability. The following research areas are among

the most promising but require further investigation. They are listed in approximate order

of priority for WIST needs.

A. Detection and prediction of road/rail conditions in complex terrain. Complex

terrain provides a particularly difficult setting for diagnostic/prognostic systems

focused on road/rail conditions. Research is required to discover the best ways to

deal with complex terrain at high resolution in numerical models, interpolation

schemes, and data fusion systems. FT

B. Predicting precipitation type. For assessing the impact of precipitation on road

and rail condition, predictive systems are required that provide much higher

spatial and temporal resolution for occurrence of sleet, snow, freezing rain, or

rain. NT, FT

C. Systems for predicting track/road washouts. Decision support systems are needed

to determine the likelihood, presence of, and future location of debris flows that

will result in track/road washouts. FT

D. Flood prediction systems. More accurate systems (models, decision support

systems, real-time sensing systems, etc.) are required to provide more accurate

prediction of road/track flooding, particularly in data-sparse regions. NT, FT

E. Land surface modeling. Land surface models coupled to atmospheric mesoscale

models need more development. An efficient system could serve as a translator

of atmospheric data into surface conditions near a roadway or railway. NT, FT

F. Thermal mapping. Surface-based and space-based thermal mapping has the

potential to provide the spatial distribution between surface observation sites

(point observations) along roadways and railways. Accurate interpolation of

temperature at a high spatial resolution is necessary to predict microscale effects,

and therefore necessary to provide a highly resolved and highly accurate forecast

of road temperature. Investigators at Montana State University have developed a

promising prototype that needs further support. NT

G. Snowdrift prediction from numerical models. (The U.S. Army Corps of Engineers

Cold Regions Research and Engineering Laboratory [CRREL] has done

pioneering work in this area, but more emphasis and much more research is

needed on application to surface transportation sectors.) NT, FT

H. Predicting precipitation rate and quantity. For assessing road and rail conditions,

systems must be able to predict precipitation rate and quantity at much higher
Weather Information for Surface Transportation

E-4

spatial and temporal resolution than is currently possible, particularly for the nearterm forecast (0-6 hours) and for convection-induced precipitation events. NT

J. Mobile sensor systems. The number of temperature observations taken along

roadways could be significantly increased using manufacturer-installed

temperature sensors in automobiles, commercial vehicles, and government

maintenance vehicles. An R&D program is needed to assess the value of such

observations and design quality control, data collection, and distribution

subsystems. NT, FT

K. Determination of surface insolation at high resolution (1 km) using remote

sensors. University of Wisconsin investigators have done excellent work in this

area for applications to agricultural crops and freeze warnings. Remote sensing

data of this type could become a valuable component of data fusion systems

designed to estimate road/rail surface temperatures. NT, FT

L. Measurement of snow depth near roadways/railways. Cost-effective and accurate

systems to automatically measure snow depth along road/railways are needed. NT

M. Effect of contaminants (ice, water, snow, chemicals, etc.) on road temperature.

Much work has been done in this area, but more is needed. NT, FT

N. Effects of traffic volume on road condition. Advanced decision support systems

for winter road maintenance need to incorporate quantitative models of the effects

of traffic on the temperature, wetness, snow depth, and ice compaction along

roadways. FT

P. Estimating snow depth from radar remote sensing. Much work needs to be done

to produce reliable algorithms for estimating snow depth and water equivalent.

NT, FT

Q. Remote sensing of road contaminants. The ability to provide diagnostic and

prognostic road condition information across all roads in the U. S. network

requires methods of surveillance that go far beyond today’s point sampling

technologies using fixed observation sites or mobile platforms. FT

R. Measurement and prediction of subsurface conditions, such as frost and water

flow, that affect road/rail stability and surface condition. NT, FT

III. Detection and Prediction of Reduced Visibility

Unexpected low visibility caused by fog, smoke, dust, rain, snow, or other atmospheric

obscurants along railways and roadways is responsible for many accidents annually.

Research is required in the following areas.

A. Data fusion systems for detection of low visibility. (System development and

research are needed to produce visibility information based on the fusion and

analysis of raw data from various sources, including numerical models, satellitebased sensors, ground-based sensors, and others.) FT

B. Spatial distribution of blowing/drifting snow and its impact on roadway visibility.

(FHWA research underway at University of North Dakota). NT
Weather Information for Surface Transportation

E-5

C. Visibility Prediction Systems. Forecast systems are needed that merge real-timedata and model data to provide near-term (0–6 hour) forecasts at high resolution

and accuracy. Such systems could be used on highways to trigger variable

message signs or in-vehicle information systems to give travelers warnings,

advisories, and cautions. FT

IV. Detection and Decision Support for High Wind Events

High wind events such as tornadoes, downbursts associated with convective activity,

strong density currents moving through narrow channels in high terrain, mountain

downslope winds, and tropical systems making landfall can seriously affect traffic

volume and safety of operators along roads and railways, particularly for high-profile

vehicles.

A. Decision support systems are needed that combine the best information available

from the atmospheric diagnostic and prognostic system with traffic operational

data. Such a system would include algorithms that would diagnose and predict

crosswind, headwind and tailwind components along all relevant road and

railways. The crosswind components would trigger warnings, advisories and

cautions. The headwind and tailwind data could be used for more efficient

routing of commercial vehicles or large privately owned vehicles like RVs. FT

B. Wind Diagnosis Using Remote Sensors – Much more work is needed in

developing algorithms that use satellite multispectral data, radar data, and lidar

data to detect air movement, particularly to detect hazardous high winds. NT, FT

V. Requirements for Improved Weather and Surface Sensing and Measuring

Technologies (Satellite-based, Radars, Fixed and Mobile Surface or NearSurface Platforms)

A. Standards for accuracy and all data quality factors affecting the utility of the data.

For example, review and adopt/adapt national and international standards for

environmental data objects, message sets, and icons. NT, FT

B. Calibration and validation methods. NT

1. Use of remote sensing to complement/supplant in situ sensing. NT

2. Appropriate sensor investment and siting, by climate and functional class of

sensor/facility. NT

C. Standard methodologies for collecting, processing, and archiving

sensor/measurement data. NT

D. Technologies and standards for access to and assimilation of sensor/measurement

data. NT, FT

1. Assimilation of ESS observations with other weather observations for quality

control of ESS and augmentation of traditional weather observations. NT

2. Improved nowcasts and near-term forecast predictions of open water currents

using new current measurement systems and improved forecast models. NT,FT
Weather Information for Surface Transportation

E-6

F. Facilitate ingest and assimilation of observations of “nontraditional” weather and

environmental elements into WIST systems by developing improved metadata,

standards, and calibration for such observations. NT, FT

G. Environmental sensor technologies for ITS and MTS that reduce cost and

improve effectiveness. NT, FT

H. Tradeoffs between sensor-based time series prediction versus weather-based heat

balance prediction for parameters such as surface freezing and temperature/rate

extremes. NT,FT

VI. Information Technology for Access and Application of WIST, Including WIST

inputs to ITS

A. Develop better computer-based systems for communicating and processing

WIST, including the capability to integrate total environmental information from

air, sea, and land sensors and other sources. Such systems should be able to

incorporate information on evolving weather conditions and other environmental

elements into an open system adhering to the information architectures of the

national ITS and a national weather information system. NT, FT

B. Refine in-vehicle displays for WIST and other ITS decision-support tools that use

WIST. NT

C. Develop filtering and fusion processes to tailor increasingly abundant information

and data for specific decisions in mobile and fixed environments and for purposes

of safety-warning, operations, and planning. NT, FT

1. Coordination of multiple local-domain NWP models (e.g., ensembles and

boundary reconciliation) for transportation applications. NT, FT

2. Flexible “scripting” to tailor information dissemination from general

information sources (e.g., ITS) to end users’ decision systems. NT

D. Develop “intelligent” decision support systems, e.g., systems that learn and can

collaborate with other systems and with humans. NT, FT

E. Conduct human-factors research to improve the human-machine interface, impact

of information, and standardization of graphical displays in decision support

applications. NT

F. Apply advanced communication technologies and graphical products to decision

support systems, particularly those for mobile and remote decision nodes of ITS.

NT, FT

VII. Requirements for Development and Improvement of Misoscale to Mesoscale

Numerical Models for Transportation Applications

A. Finer-scale forecast skill in mesoscale weather prediction models used for

multiple purposes in addition to surface transportation weather. NT, FT

B. Incorporation of land-surface features near roadways into local-scale models of

weather parameters. NT, FT
Weather Information for Surface Transportation

E-7

C. Improvement of pavement condition models and local-scale weather forecast

models through incorporation of data from next-generation road condition

reporting systems. FT

D. Use of artificial intelligence techniques to improve the spatial resolution of

weather forecast models. FT

E. Impact of high spatial and temporal variability of land use and land cover on

mesoscale models with grid spacing less than 4 km. (Research currently supported

by the U.S. Army for non-roadway applications should be transferable to surface

transportation applications.) NT, FT

F. Roadway weather modeling that incorporates the surface–atmosphere system

along and adjacent to the road and provides a framework for traffic and road

operations management decision-support systems. (Long-term effort currently at

“vision” stage.) FT

G. Predictive models for air and water dispersion of chemical, biological, and

nuclear hazards associated with HAZMAT transportation incidents. NT, FT

H. Improve oceanographic sensors and models that incorporate weather data with

water levels, tides, and currents to improve forecasts of conditions on MTS

waterways and open water routes. NT,FT

VIII. Interactions of Transportation Weather with Other Decision Support Factors

A. Improve understanding and models for the uncertainties, risks, and cost–benefit

outcomes related to incorporating weather/geophysical observations and

prediction in surface transportation decision processes. FT

B. Operational research to understand and validate the effects of weather on all

transportation outcomes, including traffic management, maintenance, emergency

management, travel planning, traveler warning, facility planning, and others. Each

decision type requires operational research to determine and validate linkages

between weather information and improved transportation outcomes. NT, FT

C. Improve understanding of and develop models for human performance and

behavior in relation to the use of weather-related current information and

forecasts (near term to very long term) in decision processes. NT, FT

D. Improve understanding of, and address the social, economic, educational, and

institutional policy issues related to, open dissemination and application of

weather information for surface transportation. NT, FT

E. Develop and distribute tools and guidance to assist decision makers when release

of contaminants or hazardous materials (spills, accidental discharges, terrorist

actions) occurs within waters of the Marine Transportation System and other

coastal environments. NT

E. Develop an understanding of, and validate with operational research, climaticscale effects on facility and operations planning in the surface transportation

sectors. NT, FT
Weather Information for Surface Transportation

E-8

F. Improve the estimation and presentation of risk in all weather and geophysical

measurements and predictions related to surface transportation decisions and

outcomes. Validate that end users comprehend the risk information well enough

to affect their decisions and outcomes. The decision areas and outcomes include

safety, mobility, productivity, environmental quality, and security. Risk

communication topics to be explored include:

1. Dissemination of observation confidence and quality-control metrics from

data assimilation processes. FT

2. Increased use of model ensemble and output statistics. NT, FT

3. Integrating the spatial, temporal, and intensity dimensions of risk in

precipitation and other weather events. NT, FT

G. Transportation outcome quantification of improved environmental information,

decision support and technique (generally requiring large cross-sectional or

longitudinal studies with controlled interventions). FT

IX. Requirements to Extend the Fundamental Knowledge Base Supporting WIST

Technology Development and Application

A. Improve the scientific understanding of atmospheric scales (spatial and temporal)

and the thresholds of weather and geophysical parameters that affect surface

transportation. NT, FT

B. Statistical filtering and prediction techniques applicable to roadways, railways,

and waterways. NT, FT

C. Assess and develop controls for electromagnetic effects (e.g., solar weather) on

ITS equipment. NT

D. Develop improved weather forecasting and climate monitoring applications in

support of the USDOT/NOAA Interagency Agreement for the Nationwide

Differential GPS. FT

E. Determine the total observational requirements, including those from

transportation facilities, to achieve numerical weather prediction (NWP) quality

sufficient for all WIST user needs. FT

X. Education and Training to Provide Human Resources in WIST R&D

A. Develop academic curricula and training that spans meteorology and

transportation applications. (The growth of the private sector WIST provider

community will create career opportunities for appropriately educated

individuals.) NT, FT

B. Attract the interest of the meteorological research community and enhance its

participation in WIST applications R&D. Encourage the development of

academic research centers with a focus on transportation-related weather issues

and meeting the evolving needs of WIST user communities. NT, FT

C. Make the United States competitive with international research capabilities in

applied weather information. NT, FT
F-1

Appendix F

Federal Entities and Program Activities

Relevant to WIST
F-2

Federal Entities and Program Activities

Relevant to WIST

OVERVIEW

This appendix expands on the Chapter 3 summaries for the federal partners in the Federal

Committee for Meteorological Services and Supporting Research (FCMSSR)

Each section begins with a table for the entities within one federal department or independent

agency. These tables identify each transportation sector of significant interest to each federal

entity’s constituent groups, or otherwise of significant interest to that federal entity. The

following federal entities are represented:

• Department of Transportation

• Department of Energy

• Department of Defense

• Department of Commerce and the National Oceanic and Atmospheric Administration

• Department of the Interior

• Department of Agriculture

• Environmental Protection Agency

• Federal Emergency Management Agency

• National Aeronautics and Space Administration

• Nuclear Regulatory Commission

• U.S. Postal Service
F-3

DEPARTMENT OF TRANSPORTATION

The mission of the Department of Transportation

(DOT) is to develop and coordinate national

transportation policies that will provide an efficient and

economical national transportation system, with due

regard for need, the environment, and national defense. The DOT is the federal entity with

primary responsibility for shaping and administering policies and programs to protect and

enhance the safety, adequacy, and efficiency of transportation systems and services. In addition,

it promotes intermodal transportation.

The DOT includes the Office of the Secretary and

13 operating administrations, each headed by a

presidential appointee. Among these

administrations are the Federal Highway

Administration (FHWA), National Highway

Traffic Safety Administration (NHTSA), Federal

Transit Administration, Federal Railroad

Administration, Federal Aviation Administration

(FAA), Maritime Administration, Saint Lawrence

Seaway Development Corporation, Research and Special Programs Administration (RSPA), the

U.S. Coast Guard, and the Transportation Security Administration (TSA). These operating

administrations within DOT provide policy and oversight for all the modes of surface

transportation covered by the WIST needs study (Table F-1).

Table F-1 Interests of DOT Constituencies in Transportation Sectors

Transportation Sectors of Constituencies

Department of Transportation Road Rail MTS Pipeline Transit

Airport

Ground Ops

Federal Highway Administration X

Federal Transit Administration X X X X

National Highway Traffic Safety Admin. X X

Federal Railroad Administration X

Maritime Administration X

St. Lawrence Seaway Corporation X

U.S. Coast Guard X

Research & Special Programs Administration X X X X X X

Office of Emergency Transportation X X X X X X

Office of Hazardous Materials Safety X X X X X

Office of Pipeline Safety X

Federal Aviation Administration X

Center for Climate Change & Environ. Forecasting X X X

Transportation Security Administration X X X X X X

“[T]he Act which I sign today is the most important

transportation legislation of our lifetime ... It is one

of the essential building blocks in our preparation for

the future ... Transportation has truly emerged as a

significant part of our national life. As a basic force

in our society, its progress must be accelerated so

that the quality of our life can be improved.”

President Lyndon Johnson, signing the act that established

the Department of Transportation, October 15, 1966

DOT Role: Policy and oversight for all

transportation systems in the nation
F-4

The DOT Office of the Secretary oversees the formulation of national transportation policy and

promotes intermodal transportation. Other responsibilities are negotiation and implementation of

international transportation agreements, assuring the fitness of US airlines, enforcing airline

consumer protection regulations, issuance of regulations to prevent alcohol and illegal drug

misuse in transportation systems, and preparing transportation legislation.

Federal Highway Administration

The roads and highways of the United States are

planned, built, and operated through a division

of responsibilities between the federal

government and the states. The FHWA has

division offices in each state, and four regional

resource centers, as well as a headquarters office

in Washington, D.C. It performs its mission

through two main programs:

• The Federal-Aid Highway Program

provides federal financial assistance to

the states to construct and improve the

National Highway System, urban and

rural roads, and bridges. The program

includes emergency relief to help states

conduct emergency and permanent repairs of damage from natural disasters or

catastrophic failures.

• The Federal Lands Highway Program provides access to and within national forests,

national parks, the Tribal nations, and other public lands by preparing plans, letting

contracts, supervising construction, and conducting bridge inspections and surveys.

With the exception of the roads served by the Federal Lands Highway Program and some private

roads, U.S. roads and highways are built, maintained, and operated by state and local agencies

and toll authorities. The FHWA develops regulations, policies, and guidelines for federal-aid

funding, with the aim of achieving FHWA goals for mobility, safety, productivity, the human

and natural environment, and national security.

The Federal-Aid Highway Program funds state highway research, but the FHWA also manages a

national research, development, and technology program that includes the Intelligent

Transportation System (ITS), through the ITS Joint Program Office. The work on Surface

Transportation Weather Decision Support Requirements (STWDSR), including the Maintenance

Decision Support System (MDSS), described in Section 1.3.1, is part of the ITS initiative

(Nelson 2001, Mahoney 2001, NCAR 2002).

The FHWA delivers technical training, education, and assistance to its own staff and partners in

areas of:

• Roadway and bridge design, construction, and maintenance

Snow on the Washington, D.C., beltway. Courtesy

Blaine K. Tsugawa, OFCM staff.
F-5

• Value engineering and other project and program evaluation tools

• Policy and planning

• Highway safety

• Intelligent transportation systems

• Environmental protection and enhancement

• Innovative financing

• Land acquisition

• Research, development, and technology transfer.

The research program generally seeks to advance the state of the art in transportation systems

quality. The FHWA works with government, industry, and research-community partners to

develop, test, and implement the latest technology. Because the FHWA is charged with

coordinating highway transportation programs in cooperation with the states and other partners,

it is helping to lead the effort to revolutionize road weather information in America. Much of this

effort will have spin-off effects for improving weather information for many other modes of

surface transportation.

The offices within the FHWA that are most relevant to weather issues are the Office of

Operations and the Office of Research, Development and Technology. However, weather issues

cut across the FHWA’s programs, goals, and organizational units. This has made it vital,

although difficult, to give weather information needs a focus within the agency.

The Road Weather Management Program

Various FHWA infrastructure and research programs have long been concerned with weather,

particularly winter road maintenance. Although the mission of the FHWA does not include

producing weather information, the linkages between general weather information and relevant

threats to surface transportation (“road weather”) spans the interests of meteorology and

transportation. In 1997 the Rural ITS program began a focus on road-weather information. This

effort has evolved into the Road Weather Management Program (RWMP) within the Office of

Operations (Row 2001).

The Office of Operations, created in 1999, represents the increasing role of FHWA as a leader in

improving state and local road operations in response to synoptic scale (e.g., hurricane) and

smaller-scale weather threats. It also hosts the emergency operations component of the FHWA,

which plays a federal coordinating role during national-scale disasters. The experience with

Hurricane Floyd in particular has shaped RWMP activities aimed at augmenting the emergency

management role of the state transportation departments. The RWMP is also working with the

traffic management staff within the Office of Operations to improve ITS-based practices for

preserving mobility and safety in more common, and smaller-scaled, weather threats. Issues

concerning road weather information for travelers are dealt with elsewhere in the Office of

Operations and in the ITS program generally.

The RWMP includes work on road-weather sensing related to prediction techniques,

dissemination of road-weather information through ITS, the development of decision support
F-6

applications that use information on weather threats, and the improvement of transportation

operations to respond to threats. The RWMP has taken the lead for the FHWA in interfederal

coordination concerning road-weather information. This coordination occurs directly with

agencies like the National Weather Service (NWS) in the National Oceanic and Atmospheric

Administration (NOAA) and through the Office of the Federal Coordinator for Meteorological

Services and Supporting Research (OFCM). The RWMP brings the interests of its

constituencies, primarily the state departments of transportation, to the interfederal arena.

Winter road maintenance continues to be an RWMP focus. Through the STWDSR program, the

RWMP is leading the FHWA activity in defining road-weather sensing requirements for

integration with both ITS surveillance efforts and the national environmental observation system.

In conjunction with the Office of Research, Development and Technology, the RWMP has been

developing technology for sensing and treating winter road conditions. Among the RWMP

efforts to develop and test advanced decision support systems for WIST users are the ATWIS

and FORETELL projects, now operational in the Midwest, as well as the MDSS prototype

development program (Section 1.3.1). Through the COMET program, the RWMP has sponsored

five university-NWS-state research projects to improve deployment and application of roadweather sensors.

The RWMP has worked with the ITS Joint Program Office to define the flows of weather and

related data in the National ITS Architecture (Section 1.3.1). This effort includes developing the

ITS user service for Maintenance and Construction Operations and integrating weather data

standards into Version 4 of the National ITS Architecture. Because the construction and

operational interests of the FHWA are mostly indirect, the FHWA controls no large operating or

project funds, comparable to programs of the FAA, NWS, or Department of Defense (DoD).

However, the RWMP works through the interfederal coordination process to bring the

requirements of the ITS into meteorological information systems and observing platforms.

Climate Information and its Relevance to Surface Transportation

Interests in road weather differ, within the FHWA and elsewhere in the DOT, depending on the

temporal and spatial scales of weather information. Climate information is most relevant to

infrastructure planning and the long-range management of operations resources. The Office of

Planning and Environment is the FHWA unit that works most closely with the DOT Center for

Climate Change and Environmental Forecasting, which focuses on climate issues and their

impacts on the surface transportation system, such as long-term highway inundation.

Federal Transit Administration

The Federal Transit Administration, through its funding program, assists in developing improved

mass transportation systems for cities and communities across the country. Beyond typical bus

and rail systems, it supports other forms of public transportation, including commuter ferryboat,

trolleys, and people movers. A wide range of technical and planning assistance helps transit

agencies’ to develop their service operations, building and construction, capital investments, and

joint development efforts. Through its technology programs, the Federal Transit Administration

supports research on intelligent transportation systems, alternative fuels, and new communication

technologies. System-wide applications of advanced new technologies have contributed to transit
F-7

agencies becoming more integrated with other transportation and information networks, while

also increasing access, cost-effectiveness, and convenience. Other programs play a significant

role in helping to minimize air pollution and single-occupant vehicle traffic in congested urban

environments. Programs and technologies such as the Bus Rapid Transit Initiative and

communication-based train control are improving the viability of transit services in meeting

current and future needs of the traveling public. Across the nation, the Federal Transit

Administration is helping to create neighborhoods that are more amenable to transit and

pedestrian travel, ultimately enhancing the quality of life and making communities more livable.

National Highway Traffic Safety Administration

NHTSA is responsible for reducing deaths, injuries, and economic losses resulting from motor

vehicle crashes. It sets and enforces safety performance standards for motor vehicles and

equipment. Through grants to state and local governments, it enables them to conduct effective

local highway safety programs. The statistics on highway accidents, including injuries and

economic consequences of accidents, cited in this and most other WIST-related reports originate

from NHTSA databases.

NHTSA investigates safety defects in motor vehicles; sets and enforces fuel economy standards;

helps states and local communities reduce the threat of drunk drivers; promotes the use of safety

belts, child safety seats, and air bags; investigates odometer fraud; establishes and enforces

vehicle antitheft regulations; and provides consumer information on motor vehicle safety topics.

It also conducts research on driver behavior and traffic safety, to develop the most efficient and

effective means of bringing about safety improvements

Federal Railroad Administration

The Federal Railroad Administration

promotes safe and environmentally sound rail

transportation. With its responsibility for

ensuring railroad safety throughout the

nation, it employs safety inspectors to

monitor railroad compliance with federally

mandated safety standards, including track

maintenance, inspection standards, and

operating practices. The Federal Railroad

Administration conducts tests to evaluate

research and development projects that

support its safety mission and enhance the

railroad system as a national transportation

resource. It also administers public education

campaigns on highway–rail grade crossing

safety and the danger of trespassing on

railroad property.

Railroad bridge washed out by hurricane flooding.
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Maritime Administration

The Maritime Administration promotes development and maintenance of an adequate, wellbalanced, U.S. merchant marine, sufficient to carry the nation's domestic waterborne commerce

and a substantial portion of its waterborne foreign commerce. The merchant marine can serve as

a naval and military auxiliary in time of war or national emergency. The Maritime

Administration also seeks to ensure that the United States enjoys adequate shipbuilding and

repair service, efficient ports, effective intermodal water and land transportation systems, and

reserve shipping capacity in time of national emergency.

Saint Lawrence Seaway Development Corporation

The Saint Lawrence Seaway Development Corporation operates and maintains a safe, reliable

and efficient waterway for commercial and noncommercial vessels between the Great Lakes and

the Atlantic Ocean. In tandem with the Saint Lawrence Seaway Authority of Canada, it oversees

operations safety, vessel inspections, traffic control, and navigation aids on the Great Lakes and

the Saint Lawrence Seaway.

U. S. Coast Guard

The Coast Guard ensures safe and secure transportation on America’s waterways and protection

of the marine environment. The Coast Guard’s job of ensuring maritime safety and security will

become even more challenging in the years ahead, driven by three transportation trends. First,

domestic and ocean-borne trade and cruise ship demand are poised for explosive growth in the

size and number of ships plying inland, coastal, and deepwater waterways. Second, fishing

vessels and offshore platforms venture farther offshore in search of the sea’s bounty. Third, a

dramatic increase in personal watercraft and recreational boating is driving ever greater

congestion on the nation’s waters. Prevention, founded on expert risk assessments to reduce the

probability of mishaps, will be the watchword of the future. Advanced technologies will continue

to be embraced to increase the probability of success of the Coast Guard mission.

Among the Coast Guard’s weather related duties is participation in the International Iceberg

Patrol, which aims to provide

safe navigation in the

northwest Atlantic Ocean by

monitoring the location and

movement of icebergs.

A sinking tanker leaking oil.

Photo courtesy NOAA Photo

Library.
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Research and Special Programs Administration

The RSPA oversees rules governing the safe transportation and packaging of hazardous materials

by all modes of transportation, excluding bulk transportation by water. It also assists local and

state authorities with training for hazardous materials emergencies. Research and development

play a major role in RSPA’s mission. In addition, RSPA operates the Volpe National

Transportation Systems Center in Cambridge, Massachusetts, which is dedicated to enhancing

the effectiveness, efficiency, and responsiveness of other federal organizations with critical

transportation-related functions. Three entities within the RSPA have special relevance to WIST

needs and applications: the Office of Emergency Transportation, Office of Hazardous Materials

Safety, and Office of Pipeline Safety.

Office of Emergency Transportation

Transportation is a vulnerable lifeline, but during and after disasters it becomes essential for

helping a community recover and restore its economy. To provide a centralized, effective

program, the Office of Emergency Transportation performs coordinated crisis management

functions for multimodal transportation emergencies. An emergency may result from:

• Natural disasters

• Technological incidents and accidents

• Labor strikes

• Security situations, such as domestic criminal acts or acts of terrorism

• National defense mobilization.

Extreme weather falls under the category of natural disasters. Adverse weather events in this

category include hurricanes, tornadoes, major flooding, and similar events that cause disruptions

in transportation systems for which coordinated crisis management is required. Preparation and

training for emergency events include exercising every component of the team and every aspect

of the plan, so that surprises will be minimal when critical decisions must be made and

implemented. The Office of Emergency Transportation also works with other federal and state

agencies to ensure relationships are in place before the stress of disaster response begins.

Activities within the Office of Emergency Transportation include:

• Managing the DOT Crisis Management Center to collect, analyze, and disseminate

critical transportation infrastructure information to senior DOT officials, and to

ensure that communications and other equipment are ready at any time

• Managing the Alternate Relocation Site for core DOT functions so that the

Department can continue to work even if the headquarters is unusable

• Developing and continually revising and testing plans and procedures to meet new

threats and take advantage of new technology and other advances

• Training DOT staff for disaster functions that are essential but not performed

frequently.
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Office of Hazardous Materials Safety

The mission of the Office of Hazardous Materials Safety is to promulgate a national safety

program that will minimize the risks to life and property inherent in commercial transportation of

hazardous materials. The functions of the Office of Hazardous Materials Safety fall into five

categories: regulatory development, enforcement, training and information dissemination,

domestic and international standards, and interagency cooperative activities. The standard form

used by the Office to report a transportation incident includes questions on weather conditions at

the time of the incident, such as precipitation, pavement condition, winds, or sun glare.

Weather events affect the transportation of hazardous materials in two ways. First, exposure to

specific kinds of weather may increase the vulnerability of hazardous materials in transit.

Second, weather and related condition can affect the consequences of a release of hazardous

materials through atmospheric dispersion, water contamination, and other routes.

Office of Pipeline Safety

The Office of Pipeline Safety administers the DOT’s national regulatory program to ensure the

safe transportation of natural gas, petroleum, and other hazardous materials by pipeline. It

develops regulations and other approaches to risk management, to assure safety in design,

construction, testing, operation, maintenance, and emergency response of pipeline facilities.

Pipeline safety standards are established and maintained by the Office of Pipeline Safety to

ensure public safety and environmental protection from gas and hazardous liquids transported by

pipeline.

Various types of weather phenomena can be listed as causal events in the standard form used by

the Office of Pipeline Safety for reports of accidents and incidents involving natural gas or

hazardous liquid pipelines. A section on the form called “Apparent Cause” lists “Natural Forces”

as a subsection, with four types of weather events among the list of choices: lightning, heavy

rains/floods, temperatures, and high winds. Heavy rains are further categorized by their effects

(washouts, flotation, scouring, other). Temperature as a cause is also further categorized as

thermal stress, frost heaves, frozen components, or other.

Federal Aviation Administration

The FAA oversees the safety of civil aviation. The

agency is responsible for certification of airports

serving air carriers. It also regulates a program to

protect the security of civil aviation and enforces

regulations under the Hazardous Materials

Transportation Act for shipments by air. In addition

to operating a network of airport towers, air route

traffic control centers, and flight service stations, the

FAA develops air traffic rules, allocates the use of

airspace, and provides security control of air traffic

to meet national defense requirements. Holman Field, St. Paul, Minnesota, flooded by the

Mississippi River, April 2001. Copyright AP Wide

World Photos.
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At air terminals, the FAA is responsible for coordinating or controlling operational movements

on the ground. This responsibility includes movement of aircraft, freight vehicles, baggage

movers, and support equipment such as fuel, food, and maintenance vehicles.

The FAA supports the collection of weather information for aviation and for all other weather

services and databases through a large number (767) of automated observing systems. It also

continues to fund contracts for human weather observers (198) at critical locations. It also

supports R&D on aviation weather, to ensure the safety, capacity, and efficiency of the national

aviation system.

Center for Climate Change and Environmental Forecasting

The Center for Climate Change and Environmental Forecasting was established within DOT in

1999 to coordinate Departmental strategies and policies for mitigating transportation’s

contribution to greenhouse gas emissions and assessing the effects of climate change on the

transportation system. The Center functions as a DOT-wide virtual organization, led by a

steering committee composed of senior executives from nine of the DOT operating

administrations and the Office of the Secretary. This cross-modal, virtual structure helps to

ensure strong participation throughout the Department, while avoiding unnecessary

administrative and institutional costs. The operating administrations support the Center's work

through contributions of funds, staff, and technical expertise. They participate in the Center’s

efforts to share information, build partnerships, and coordinate activities related to climate

change.

The Center sponsors several projects including the following:

• Impacts of Climate Change on Transportation. The Center is undertaking a series

of research projects to assess how short and long term changes in climate could affect

transportation, and how transportation decision makers could address these possible

impacts.

• Fuel Options. This study compares the energy use, emissions of greenhouse gases

and criteria pollutants, and cost-effectiveness of current and alternative fuels for lightduty and heavy-duty highway vehicles.

• Transportation Greenhouse Gas Data and Modeling. This study analyzes data and

models being used to improve understanding of greenhouse gas emissions from the

transportation sector and the implications of policy options.

Transportation Security Administration

The TSA was established by Public Law 107-71 following the terrorist attacks of September 11,

2001. Its primary objective is to stop terrorist incidents before they can be implemented. When

fully operational, the TSA will have thousands of federal law enforcement, security, and

regulatory employees at 429 airports across the country. Although protecting the traveling public

in airports and on airplanes may be the most visible responsibility of the TSA, it also has lead

responsibility for security of the nation’s highways, waterways, seaports, railways, public transit,
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and pipelines (DOT 2002). Thus, all the surface transportation sectors studied for this WIST

report are within its purview.

Weather conditions have direct and indirect implications for the mission of the TSA. First, as in

any emergency response situation, weather conditions may influence the ability of responders to

a homeland security incident. Second, prevailing and forecast conditions can be critical to

effective response and recovery, if an attack disperses a chemical, biological, or radiological

hazard. Third, heightened security measures after September 11 may increase the impact of

adverse weather on the efficiency and effective capacity of transportation systems (e.g, bridge

and facility entrances) or intermodal connections (e.g, airport parking lots and passenger

terminals, seaport-to-rail/roadway carrier links).

DEPARTMENT OF ENERGY

The mission of the Department of Energy (DOE) is to

foster a secure and reliable energy system that is

environmentally and economically sustainable, to be a

responsible steward of the nation's nuclear weapons, to

clean up its own facilities, and to support continued

United States leadership in science and technology.

A large part of the work performed by the DOE and its partners is the safe management of

nuclear materials and permanent disposal of the nation's radioactive wastes. This work includes

packaging, transporting, and storing these hazardous materials.

Table F-2 Interests of DOE Constituencies in Transportation Sectors

Transportation Sectors of Constituencies

Department of Energy Road Rail MTS Pipeline Transit

Airport

Ground Ops

National Transportation Program X X X X

Power Marketing Administrations X

DOE’s packaging and transportation activities are performed through program offices, which

provide policy direction and program oversight. Materials transported in these activities range

from weapons components and subassemblies to spent fuel, special nuclear materials, and

radioactive or otherwise hazardous waste materials. Field offices are responsible for detailed

planning for shipments and for full regulatory compliance. They also serve as focal points for

local public and stakeholder interactions.

DOE ships its materials by all modes of transportation, using both commercial and private

carriers. In FY 1997 the distribution by sector was 77 percent by air, 22 percent by roadway

(motor carrier), and less than 1 percent by rail. In FY 1997, DOE transported 430,000 shipments

of non–defense-related materials, consisting of 412,000 (96 percent) nonhazardous shipments

and 18,000 shipments (4 percent) of hazardous materials. Of the latter, 5,200 were radioactive.

Although shipments of radioactive materials were thus only 1.2 percent of all DOE shipments,

DOE ships 75 percent of all curies (a measure of radioactivity) transported in the United States.

DOE Role (Table F-2): Transportation of

nuclear materials, through its National

Transportation Program, and repair crew

access to electric transmission lines.
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National Transportation Program

The National Transportation Program (NTP), which is DOE’s corporate center for packaging and

transportation expertise, is located and managed within the Office of Environmental

Management. The NTP supports infrastructure and coordinates transportation activities for all

nonclassified shipments of hazardous materials, including radioactive materials, mixed wastes,

and commodities such as coal, other fuels, maintenance materials, and supplies.

The NTP is responsible for ensuring the availability of safe, secure, and economical transport

services; consistency in regulatory implementation; and coordinated outreach and emergency

preparedness assistance for DOE programs. The NTP develops and provides training on

transportation and packaging management and safety, including domestic and international

regulations, guidance, and standards.

Federal Energy Corporations—The Power Marketing Administrations

The Power Marketing Administrations (PMAs) are power utilities

that are agencies of the DOE. Their

role is to sell, in the wholesale

market, electric power and

associated energy produced at

federal dams (and some nonfederal

power plants). By law, the power is

marketed to publicly held entities

such as rural electric cooperatives

and municipal utilities first,

followed by commercial or

industrial customers within the

region. Any remaining surplus

power is sold to customers outside

the region. The regions for four of

the PMAs are shown in Figure F-1.

The fifth PMA is the Alaska Power

Administration.

The PMAs have a significant need for weather information, although most of it is required for

managing water resources and long-term planning of power production. Within the scope of the

WIST study, the information needed is mostly limited to weather elements that affect the ability

of repair crews to service power transmission lines. Consequently, the WIST needs of the PMAs

are similar to those of other utilities operating a fleet of repair trucks, such as telephone or cable

TV companies. Those needs focus on weather elements such as freezing rain, deep snow, and

other precipitation impacts.

The Bonneville Power Administration, with headquarters in Portland, Oregon, covers the

Pacific Northwest. It markets the wholesale electric power produced at 29 federal dams located

Figure F-1 PMA Regions.
F-14

in the Columbia–Snake River Basin, as

well as the power from one nonfederal

nuclear plant. Like all the PMAs,

Bonneville does not own or operate any

federal dams. It only sells the power

produced by these facilities. Two other

federal entities, the U.S. Army Corps of

Engineers and the Bureau of

Reclamation, operate the dams whose

electric energy output is sold by this

PMA. The nuclear plant is owned by

the Washington Public Power Supply

System, a consortium of utilities.

Today the Bonneville Power

Administration sells about 46 percent of

the electric power consumed in the

northwestern United States. To deliver

that power, it owns and operates one of the largest high-voltage electrical transmission systems

in the world, with 15,000 miles of power lines, constituting about three-fourths of the region’s

high-voltage electric grid.

The Southeastern Power Administration, headquartered in Elberton, Georgia, markets the

electric power and energy generated at hydroelectric dams operated by the U.S. Army Corps of

Engineers in the southeastern portion of the United States. Because this PMA does not own

transmission lines, it contracts with other utilities to provide transmission, or "wheeling"

services, for its power.

The Southwestern Power Administration, which has its headquarters in Tulsa, Oklahoma, is

responsible for marketing the hydroelectric power produced at 24 U.S. Army Corps of Engineers

multipurpose dams located in Arkansas, Missouri, Oklahoma, and Texas. This PMA operates

and maintains 1,380 miles of high-voltage transmission lines, 24 substations, and 46 microwave

and VHF radio sites.

The Western Area Power Administration has its headquarters in Lakewood, Colorado. It

markets and delivers power and related services from 55 hydroelectric plants within a 15-state

region of the central and western United States. These plants are operated by the Bureau of

Reclamation, U.S. Army Corps of Engineers, or the International Boundary and Water

Commission. This PMA operates and maintains a transmission system with more than 16,800

miles of transmission lines, as well as 256 substations and other related facilities.

Bonneville Dam, one of the sources of power marketed by the

Bonneville Power Authority. Photo courtesy Bonneville Power

Authority.
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DEPARTMENT OF DEFENSE

In addition to being a consumer of

transportation weather information, the

DoD is also one of the nation’s

principal producers of weather

information. Both the Air Force and the

Navy have weather observation and

prediction as elements of their mission.

The Air Force provides the weather

information required by the combat

forces of the Air Force and the Army.

The Navy provides weather information

for Navy and Marines Corps forces.

Table F-3 Interests of DoD Constituencies in Transportation Sectors

Transportation Sectors of Constituencies

Department of Defense Road Rail MTS Pipeline Transit

Airport

Ground Ops

U.S. Transportation Command X X X X X

 Military Traffic Mgmt Command X X X X X

U.S. Air Force X X

U.S. Navy X X X

Defense Logistics Agency X

U.S. Transportation Command

The mission of the U.S. Transportation Command (USTRANSCOM) is to provide air, land, and

sea transportation for the DoD both in times of peace and in war. It has been designated the

single manager of the Defense Transportation System. Strategic mobility is the instrument that

allows the United States to act upon the world stage at whatever level is chosen by the national

leadership. The potential range of regional threats in the next 20 years is so broad that no single

scenario can be identified as an adequate basis for planning. Current U.S. military strategy calls

for more military forces to be based in the continental United States, with a reduced forward

presence overseas. With fewer U.S. forces stationed overseas, the nation must increase its

capability to project military power abroad. USTRANSCOM must continue to strengthen and

improve all facets of strategic mobility and must be ready to react on a moment's notice. The

ability to project power worldwide rapidly depends on increased airlift capability, additional

prepositioning of heavy equipment afloat and ashore, increased surge sealift capacity, and

improved readiness and responsiveness of the Ready Reserve Force.

Military Traffic Management Command

The mission of the MTMC, the Army component of USTRANSCOM, is to support DoD and the

mobilization community worldwide during peace and war with responsive planning, crisis

response actions, traffic management, terminal operations, integrated transportation systems, and

DoD Role (Table F-3): The U.S. Transportation Command

(USTRANSCOM), through its Army component Military

Traffic Management Command (MTMC), has a major interest

in surface transportation (rail, road, and port operations).

While the MTMC is responsible for road and rail

transportation, the U.S. Army Corps of Engineers is

responsible for waterways. The Navy is responsible for open

water routes. All of the services have airport ground

operations. The Defense Logistics Agency and the Defense

Energy Support Center are responsible for pipelines.
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deployability engineering. As USTRANSCOM’s overland lift component and primary traffic

coordinator, the MTMC has assets and equipment comprising more than 12,000 containers, more

than 1,350 rail and tank cars, and 142 miles of government-owned railroad track. The MTMC

contracts with commercial transportation resources to provide additional transportation

capabilities.

With the help of these commercial industry partners, it accomplishes its mission with 2,355

active duty and reserve military members, as well as Department of the Army civilians, stationed

around the world. These professionals come from all branches of the Armed Forces: Army,

Navy, Air Force, Marines, Coast Guard, and the Canadian Armed Forces. This personnel

strength almost doubles during mobilizations, when Reserve Component units augment the

regular service personnel.

U.S. Air Force

The mission of Air Force Weather is to provide timely, accurate, and relevant mission weather

and space environmental information to meet Air Force, Army, Joint, and other defense and

intelligence community needs worldwide. These needs include weather support to surface

transportation and airfield ground operations worldwide. To accomplish its mission, Air Force

Weather executes five core processes: data collection, analysis, forecasting, tailoring, and

dissemination. On a global scale, it leverages the numerical weather prediction capabilities of the

U.S. Navy and the NWS. It also supports global meteorological satellite applications as the DoD

Meteorological Satellite Center of Excellence. For regional scale information down to “mission

scales,” it exploits meteorological satellites and a suite of models, including the communitydeveloped MM5 mesoscale model, to produce fine-scale weather forecasts for the gamut of

aviation and ground activities.

Air Force Weather provides space environmental support for DOD operations. This support is

increasingly important within the DOD, as space operations become critical to supporting

warfighting operations. Space weather events can affect key military capabilities such as radio

communications (HF and UHF), satellite operations, space object tracking, high-altitude flights,

radar operations, and the Global Positioning Satellite system.

To meet this spectrum of requirements, Air Force Weather activities are organized across the

breadth of military operations, from strategic to operational and tactical levels. The Air Force

Weather Agency (AFWA) is the primary strategic center providing global and other large-scale

support to strategic customers and Operational Weather Squadrons around the world. As an

example, AFWA provides gridded precipitation information to the Army Corps of Engineers to

support waterways management. To mitigate the impacts of space weather on DOD and national

systems, AFWA also provides space weather observations, forecasts, alerts and warnings, and

tailored products. It ensures that information on the space environment is available for

warfighters and decision makers at strategic, operational, and tactical levels.

The Air Force Combat Climatology Center, a strategic center under AFWA, provides

climatological support including engineering weather data for applications such as road building

and simulation support for development and testing of surface transportation systems. The eight

Operational Weather Squadrons provide regional forecasting services, warnings, and advisories
F-17

to protect life and resources and preserve operational capability. These units produce information

products tailored for use by Combat Weather Teams, which provide direct support to Air Force

and Army operations at the tactical level. Combat Weather Teams provide surface weather

decision information for the movement of personnel, equipment, and weapons on and around Air

Force and Army installations, as well as for operations en route to and from airports and sea

ports. They produce information products that are highly tailored to individual missions and

activities. They also provide weather information vital to safe and efficient ground operations on

airfields.

U.S. Navy

The Navy has the military requirement to provide meteorological products and services to

support Navy, Marine, and Joint forces. It also provides oceanographic support to all elements of

the DoD. The information is used to protect ships, aircraft, fighting forces, and shore

establishments from adverse ocean and weather conditions, as well as to provide tactical or

strategic advantage in exploiting the physical environment during military or humanitarian

operations.

Operational support within the Navy is provided by elements of the Naval Meteorology and

Oceanography Command. Navy meteorology and oceanography organizations collect

observations ashore, afloat, and through remote sensors, worldwide. They also are involved in

assimilating and processing these observations on a global basis to support analysis and

forecasting throughout the world. Environmental data are acquired through links with

distribution systems for conventional and remotely sensed data, operated by DoD or NOAA.

The Fleet Numerical Meteorology and Oceanography Center in Monterey, California, provides

global, regional, and tactical observations, analysis, and coupled air–ocean forecasts. The Naval

Oceanographic Office, located at Stennis Space Center, Mississipi, processes and distributes

oceangraphic, hydrographic, and other geophysical data and products. It is the Navy’s primary

processing facility for data from NOAA polar-orbiting satellites and the national “core

processing center” for sea-surface temperature measurements derived from satellite data.

Worldwide theater and regional support is provided to forces ashore and afloat through six

regional centers delivering meteorological and oceanographic services within their broad areas of

responsibility. Specific products common to the regional centers include warnings of high winds

and seas for the world's oceans, tailored forecast support for Navy, Coast Guard, and NOAA

ships at sea, and ship routing services for ocean transits.

The Naval Ice Center, located in Suitland, Maryland, provides tailored ice forecasts and analyses

to the DoD. The Navy, through this center, operates the National Ice Center jointly with NOAA

and the Coast Guard. The National Ice Center provides ice analyses and forecasts for the Arctic

and Antarctic regions, coastal United States waters, and the Great Lakes to civilian and military

operations.

Facilities of the Naval Meteorology and Oceanography Command—located at Whidbey Island,

Washington; Naples, Italy; and Jacksonville and Pensacola, Florida—provide aviation forecast

services, as well as Fleet Operating Area and local forecasts and warnings. These services and
F-18

products are used by aircraft, ships, submarines, and naval bases and staffs. The command also

has 31 detachments worldwide. These detachments are primarily situated at naval air stations for

aviation safety of flight forecasting, although several are located at naval stations in support of

sea-going units. They provide meteorological and oceanographic forecasting and warning

services to the DoD and allied units within their local and functional areas of responsibility.

Detachments and facilities within the continental United States use numerical weather prediction

products from both the Navy and NOAA's National Centers for Environmental Prediction.

Overseas detachments and facilities use Navy numerical products, in addition to Air Force and

foreign products.

The Navy also has permanent meteorological and oceanographic assets aboard aircraft carriers,

major amphibious ships, and command ships. Their primary objectives are safety of ships,

aircraft, and embarked personnel; optimum tactical and planning support to onboard warfare

commanders; and tailored on-scene products and services for the assigned task force, task group,

or allied units in joint, combined, or coalition military and humanitarian operations.

The Navy and Air Force have long cooperated in providing weather support for the DoD. These

efforts have led to successes such as the Defense Meteorological Satellite Program and the Joint

Typhoon Warning Center, which is operated jointly by the Navy and Air Force and located at

Pearl Harbor, Hawaii. Similarly, the Navy and NOAA have a history of cooperative efforts,

which increase efficiency and benefit both the Navy and NOAA. All three agencies continue to

identify new areas of cooperation

DEPARTMENT OF COMMERCE AND THE NATIONAL OCEANIC AND

ATMOSPHERIC ADMINISTRATION

The role of the Department of Commerce

(DOC) is to promote job creation, economic

growth, sustainable development and improved

living standards for all Americans. The DOC

accomplishes these objectives through its

various component agencies and by working in

partnership with business, universities, and

communities. The National Oceanic and Atmospheric Administration (NOAA) is the DOC’s

primary agency for weather data.

NOAA is dedicated to predicting environmental change and protecting the environment. It uses

environmental assessment and prediction to observe and analyze the state of the environment,

while protecting public safety and the nation's economic and environmental security through

accurate forecasting. Second, it practices environmental stewardship to protect ocean, coastal,

and living marine resources and enable sustainable development in the coastal zone.

NOAA provides its services through five major divisions and numerous special program units.

The major divisions are NOAA’s National Ocean Service, National Marine Fisheries Service,

Office of Oceanic and Atmospheric Research, National Weather Service, and National

DOC Role (Table F-4): NOAA’s National Ocean

Service and NOAA Corps are primarily consumers

of weather information., although some facilities

provide oceanographic and meteorological

observations. NOAA’s NWS is the principal

provider of weather information for the nation.
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Environmental Satellite Data and Information Service. NOAA also includes the nation's seventh,

and smallest, commissioned service, the NOAA Corps. The commissioned, uniformed officers of

the NOAA Corps are scientists and engineers who operate and manage NOAA's fleet of research

ships and aircraft.

Table F-4 Interests of DOC Constituencies in Transportation Sectors

Department of Commerce, Transportation Sectors of Constituencies

National Oceanic and

Atmospheric Administration Road Rail MTS Pipeline Transit

Airport

Ground Ops

NOAA’s National Ocean Service X

NOAA Corps X

NOAA’s National Weather Service X X X X X X

NOAA’s National Ocean Service

As the nation's principal advocate for coastal and ocean stewardship, NOAA’s National Ocean

Service develops the national foundation for coastal and ocean science, management, response,

restoration, and navigation. It provides nautical charting products for safe navigation to the

marine community and conducts research on the health of the coastal environment. Both

activities contribute to healthy coastal economies. The coastal ocean, which includes the coasts,

bays, estuaries, and the Great Lakes, is economically, politically, and socially critical to the

nation. Coastal communities are hubs of commerce and home to many major American

corporations, ports, and transportation networks. NOAA’s National Ocean Service works to find

innovative ways to provide information, tools, and techniques that will reduce the vulnerability

of these communities to storms, tsunamis, harmful algal blooms, fish kills, marine mammal

strandings, and other coastal hazards. It establishes coastal preparedness plans, educates the

public about coastal hazards, and develops tools, such as geographic information systems, to help

communities plan for and respond to coastal hazards. This agency also provides scientific

expertise during operations to clean up oil and hazardous chemical spills and works to restore

marine areas harmed by pollution or other damage.

Support to the Marine Transportation System

NOAA’s National Ocean Service supports the MTS with a variety of navigation and

environmental services. NOAA activities authorized by the Coast and Geodetic Survey Act of

1947 and the 1998 Hydrographic Services Improvement Act include programs for Mapping and

Charting, Hydrographic Surveys, Geodesy, and Tide and Current Data. These programs are the

backbone of the MTS information infrastructure. In addition to promoting safe and efficient

maritime commerce with its navigation services, NOAA issues marine weather forecasts,

conducts satellite-aided search and rescue tracking with the Coast Guard and other partners, and

facilitates sound port development. NOAA also supports an environmentally friendly MTS by

conducting waterway risk assessments to aid port planning, organizing spill preparedness and

response activities, and promoting fisheries management and habitat restoration. These activities

form a comprehensive and effective program supporting the future of the MTS.
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Marine Modeling and the Marine Transportation System

Predicting water levels accurately requires forecast models that incorporate weather information.

NOAA’s National Ocean Service provides real-time observations on water levels, tides, and

currents to support the MTS and safe, efficient use of the nation’s ports. NOAA merges these

oceanographic data with marine meteorological data from the NWS to develop models for

nowcasts and forecasts of water levels and conditions important for maritime commerce and safe

navigation.

NOAA data on water levels can help move ships in and out of port as quickly as possible, and as

fully loaded as safety permits. A few more inches of draft can mean additional thousands to

millions of dollars to a shipper. Loading additional cargo can take many hours, and it may take

anywhere from two to eight hours for a ship to leave a port and reach the ocean. To maximize

cargo loads, mariners need to know what the underkeel clearance will be, from 6 to 24 hours in

the future. Ships coming into port use the NOAA sensor data and models to time their arrival for

the best underkeel clearance conditions, without wasting fuel by having to wait outside a bay or

port entrance for adequate conditions.

NOAA Corps

The NOAA Corps is the smallest of the seven uniformed services of the United States. The

service, consisting of approximately 300 commissioned officers, is an integral part of NOAA. It

provides a cadre of professionals trained in engineering, earth sciences, oceanography,

meteorology, fisheries science, and other related disciplines. Officers operate research and

survey ships, fly "hurricane hunter" research aircraft into nature's most turbulent storms, lead

mobile field parties, manage research projects, conduct diving operations, and serve in staff

positions throughout NOAA. The ranks within the NOAA Corps are the same as the U.S. Navy,

from ensign to rear admiral (upper half).

NOAA Marine and Aviation Operations

NOAA operates a wide assortment of vessels to conduct hydrographic surveys, oceanographic

research, and fisheries research. These vessels, which operate under NOAA Marine and Aviation

Operations, are commanded by NOAA Commissioned Officers and crewed by wage marine

civilians. The wage marine personnel include licensed masters, mates, and engineers and

unlicensed members of the engine, steward, and deck departments. In addition, survey and

electronic technicians operate and maintain the ship's mission, communication, and navigation

equipment. The ship's officers and crew provide mission support and assistance to embarked

scientists from various NOAA laboratories and the academic research community.

NOAA’s National Weather Service

The NWS provides weather, hydrologic, and climate forecasts and warnings for the United

States, its territories, and adjacent waters and ocean areas, for the protection of life and property

and the enhancement of the national economy. The NWS has a national infrastructure in place to

gather and process data from the land, sea, and air. These data come from familiar technologies,

such as weather radars and satellites, but also from less-familiar technologies, including data
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buoys for marine observations and surface observing systems for data that help the aviation

industry.

The NWS maintains a constant vigil to provide warnings and forecasts of hazardous weather,

including thunderstorms, flooding, hurricanes, tornadoes, winter weather, tsunamis, and climate

events. It is the sole official federal voice for issuing warnings during life-threatening weather

situations. The NWS broadcasts life-saving information to the public during severe weather

events and other hazardous situations through the NOAA Weather Radio network. In addition,

the NWS relies on its partners in emergency management and the media to disseminate warnings

on severe weather and critical forecasts. With a massive modernization effort just completed

(Section 1.3.1), NWS is increasing the accuracy of forecasts and warning times, giving

communities more time to prepare for severe weather.

Weather services provided by NWS cost each American about $4 a year. This investment allows

the NWS to issue more than 734,000 forecasts (fire weather, public, aviation, and marine) and

850,000 river and flood forecasts annually. Each year, NWS issues between 45,000 and 50,000

potentially life-saving warnings of severe weather.

Every day, millions of economic decisions influenced by the weather are made in agriculture,

transportation, power, construction, and other sectors of the economy. Weather and flood

conditions affect the entire economy in many direct and indirect ways. Better weather,

hydrologic, and climate forecasts and information bring new economic opportunities to almost

every sector of the economy. The NWS provides general data and products to private-sector

meteorologists, who use this information to provide specialized services and tailored products to

clients in the transportation sectors and other industries. NWS forecasts are critical to the

commercial and private transportation sector, including airline shipping and trucking industries,

nationally and internationally. Airlines rely on short-term forecasts to position their aircraft and

adjust flight routes for economic advantage. Long-term climate forecasts help city managers

manage more cost-effectively their purchases of resources such as salt and sand for roads and

sidewalks. Hydrologic forecasts help communities protect their property by preparing for floods.

The NWS is making great strides in improving weather forecasts and warnings, with its vision of

becoming America's "no surprise" weather service. Over the past five years, it has doubled the

warning lead time for tornadoes to approximately 12 minutes. This extra warning time saves

lives. Today's three-to-four day forecast is as accurate as the two day forecast was 15 years ago.

The NWS is working now to make the 6 to 10 day forecast as accurate as the forecast for

tomorrow. Products issued around the clock by the NWS affect the lives of every American.

Important advances in the science of meteorology and hydrology, coupled with major new

technological capabilities for observing and analyzing the atmosphere, will allow the NWS to

continue providing unprecedented weather services to the nation, as it works in partnership with

other federal entities, state and local governments, and emergency management officials to

protect life and property throughout the United States.
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DEPARTMENT OF THE INTERIOR

As the nation's principal conservation

agency, the Department of the Interior

(DOI) has responsibility for most of our

nationally owned public lands and natural

resources. These areas encompass nearly

half a billion acres of federal lands,

including the entire National Park System

and vast tracts of federal lands, mostly in

the western regions of the country. Other DOI responsibilities include developing and using

resources in an environmentally sound manner.

Within the DOI are a number of bureaus and offices with interests related to WIST. These

include the Bureau of Indian Affairs, Bureau of Land Management, Bureau of Reclamation, Fish

and Wildlife Service, U.S. Geological Survey, and the National Park Service.

Table F-5 Interests of DOI Constituencies in Transportation Sectors

Transportation Sectors of Constituencies

Department of the Interior Road Rail MTS Pipeline Transit

Airport

Ground Ops

Bureau of Indian Affairs X X X X X X

Bureau of Land Management X X X X X X

Bureau of Reclamation X X

Fish and Wildlife Service X X X

National Park Service X X

U.S. Geological Survey X

Bureau of Indian Affairs

The Bureau of Indian Affairs was established in 1823 to carry out the nation’s trust

responsibilities for Native Americans. Today there are approximately 50,000 miles of road on

Tribal lands. Indian Reservation Roads are public roads that provide access to and within Tribal

reservations, trust land, restricted Tribal land, and Alaskan native villages. Approximately

25,000 miles of these roads are under the jurisdiction of the Bureau of Indian Affairs and the

Tribal nations. Another 24,000 are owned by state or local governments.

Bureau of Land Management

The Bureau of Land Management manages 266 million acres of federal land and 570 million

acres of subsurface federal mineral resources. These public lands, most of which are in the

western continental United States and Alaska, include grasslands, forests, mountains, arctic

tundra, and desert lands. The Bureau manages a wide variety of resources and activities on these

lands, including energy and minerals, timber, livestock forage, wild horse and burro populations,

habitat for fish and wildlife, wilderness areas, and archaeological and historical sites. The

DOI Role (Table F-5): The Bureau of Indian Affairs,

Bureau of Land Management, Bureau of Reclamation,

Fish and Wildlife Service, and National Park Service

manage large areas of land with roads and waterways.

The U.S. Geological Survey and Bureau of Reclamation

provide stream flow data to NWS River Forecast Centers

for use in flood forecasting.
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mission of the Bureau is to sustain the health, diversity, and productivity of these public lands for

the use and enjoyment of present and future generations.

The Bureau of Land Management administers about 85,000 right-of-way authorizations on the

public lands, including a variety of transportation-related systems for roads, railroads, and

pipelines. It maintains and manages an additional 81,000 miles of roads for public use on the

public lands. The Bureau of Land Management also administers 180,000 miles of rivers and

streams on the public lands, including more than 2,000 miles of National Wild and Scenic River

segments and 5.400 miles of floatable rivers for recreational use.

Bureau of Reclamation

The mission of the Bureau of Reclamation is to manage, develop, and protect water and related

resources in an environmentally and economically sound manner, in the interest of the American

public. This includes programs, initiatives, and activities that will help the western states, Native

American tribal nations, and others meet new water needs and balance the multitude of

competing uses for water in the West. The Bureau of Reclamation has constructed more than 350

large dams and reservoirs in the 17 western states, including Hoover Dam on the Colorado River

and Grand Coulee Dam on the Columbia River. Today, the Bureau is the largest wholesaler of

water in the country and the second largest producer of hydroelectric power in the western

United States.

Fish and Wildlife Service

The Fish and Wildlife Service operates the National Wildlife Refuge System, which comprises

more than 93 million acres in more than 570 National Wildlife Refuges and management

districts. The refuge system stretches from Florida to Alaska and includes refuges in U.S. insular

areas in the Caribbean and the Pacific. Every state and U.S. territory has at least one refuge or

management district, and most major American cities are within an hour’s drive of one. More

than 30 million people visit components of the system each year.

Of the 10,000 miles of roadway in the National Wildlife Refuge System, approximately half is

open to the public. The Fish and Wildlife Service also maintains 10,000 miles of dikes and

23,000 water control structures to maintain habitat. This roadway and waterway infrastructure is

vulnerable to extremes in precipitation, particularly to tropical storms with extreme winds and

storm surge.

National Park Service

The mission of the National Park Service is to promote and regulate the use of the national parks

in such a way as to conserve the scenery, natural and historic objects, and wildlife, leaving them

unimpaired for the continued enjoyment, education, and inspiration of current and future

generations. The National Park System of the United States comprises 384 areas covering more

than 83 million acres in 49 states, the District of Columbia, American Samoa, Guam, Puerto

Rico, Saipan, and the Virgin Islands. Since 1933 the National Park System has also included

national monuments and many historic military sites and battlefields.
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U.S. Geological Survey

The U.S. Geological Survey (USGS) serves the nation as an independent fact-finding agency that

collects, monitors, analyzes, and provides scientific understanding about natural resource

conditions, issues, and problems. It is also the sole science agency for the DOI. USGS scientists

pioneered hydrologic gauging techniques for estimating the discharge of water in rivers and

streams and modeling the flow of complex ground-water systems.

The USGS has collected water-resources data at approximately 1.5 million sites across the

United States, Puerto Rico, and Guam. The types of data collected are varied, but generally fit

into the broad categories of surface water and ground water. Surface-water data, such as gauge

height (stage) and streamflow (discharge), are collected at major rivers, lakes, and reservoirs.

These data, along with data collected by the U.S. Army Corps of Engineers, are used by the

NWS River Forecasting Centers to make critical flood forecasts throughout the nation.

DEPARTMENT OF AGRICULTURE

The mission of the Department of

Agriculture (USDA) is to enhance the

quality of life for the American people

by supporting production of agriculture; ensuring a safe, affordable,

nutritious, and accessible food supply;

caring for agricultural, forest, and range lands; supporting sound development of rural

communities; providing economic opportunities for farm and rural residents; expanding global

markets for agricultural and forest products and services; and working to reduce hunger in

America and throughout the world.

The U.S. agricultural sector is the largest user of freight transportation, accounting for nearly

one-third of all freight transportation services in the Unites States. Because most agricultural

production occurs in rural areas, a tremendous volume of transportation services is required to

move it to market. As a result, transportation modes vary by commodity and by region.

Table F-6 Interests of USDA Constituencies in Transportation Sectors

Transportation Sectors of Constituencies

Department of Agriculture Road Rail MTS Pipeline Transit

Airport

Ground Ops

Agricultural Marketing Service X X X X X X

Farm Service Agency X X X X X X

Forest Service X X X X X X

Office of the Chief Economist X X X X X X

Trucks are the primary movers of agricultural products, accounting for 45 percent of all

commodity transport. Trucks are mainly used for short hauls and move virtually all agricultural

USDA Role (Table F-6): The U.S. Forest Service manages

large areas of land with roadways. The Farm Service Agency,

through its Commodity Operations, must move agricultural

commodities effectively domestically and worldwide.
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production from the field and farm to the first consolidation point, which may be a grain

elevator, packing shed, or other facility. Among the agricultural commodities moved by truck are

field crops, fresh fruits and vegetables, livestock, meats and poultry, dairy products, and canned

goods.

Rail is the predominant transportation mode for long hauls in regions far from barge-loading

locations. Railways transport 32 percent of agricultural products. They provide the only costeffective transportation option for many agricultural shippers who are not located close to

markets or river transportation. Field crops, grain mill products, fertilizers, and pesticides move

by rail.

Barges, which account for 12 percent of agricultural transport, handle large volumes of field

crops, fertilizer, and pesticides. They provide a low-cost means of moving fertilizer and other

agricultural inputs to production regions, as well as to U.S. ports for export.

The remaining 11 percent of agricultural commodities are transported by pipelines, air freight,

and other modes. Pipelines carry just under 30 percent of the movements of fertilizers and

pesticides.

Climate and weather conditions affect seasonal demands for transportation of agricultural

commodities. Weather affects barge movement more than any other mode of agricultural

transportation. Factors such as freezing, flooding, and low water levels adversely affect the use

of inland waterways.

Agricultural Marketing Service

The Transportation and Marketing Program of the Agricultural Marketing Service brings

together a unique combination of traffic managers, engineers, rural policy analysts, international

trade specialists, and agricultural marketing specialists to help solve problems of U.S. and world

agricultural transportation. The program’s purpose is to ensure an efficient transportation system

for rural America, beginning at the farm gate. This system moves agricultural and other rural

products on the nation’s highways, railroads, airports, and waterways and into the domestic and

international marketplace. The program supplies research and technical information to producers,

producer groups, shippers, exporters, rural communities, carriers, government agencies, and

universities. The Agricultural Marketing Service publishes Grain Transportation Prospects and

the Grain Transportation Report. The former provides a periodic assessment of the grain

transportation situation and prospects for near-term grain transportation demand. This helps

railroads, producers, shippers, and receivers anticipate changes in transportation supply and

demand. The Grain Transportation Report provides information weekly on railcar loadings, rail

deliveries to ports, ocean grain freight rates, and numbers of vessels in port, as well as the

quantity of grain exported.

Farm Service Agency

USDA’s Farm Service Agency Commodity Operations handles the acquisition, procurement,

storage, disposition, and distribution of agricultural commodities. It also administers the U.S.

Warehouse Act. These activities help to achieve domestic farm program price support objectives,
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produce a uniform regulatory system for the storage of agricultural products, and ensure the

timely provision of food products for domestic and international food assistance programs and

market development programs. The Farm Service Agency arranges for commercial ocean,

ground (motor carrier and rail), and air transportation to deliver agricultural commodities

domestically and worldwide.

Forest Service

The Forest Service manages public lands in National Forests and National Grasslands. Its

responsibilities include managing national forests for multiple uses and benefits and for the

sustained yield of renewable resources such as water, forage, wildlife, wood, and recreation. The

Forest Service sustains the health, diversity, and productivity of the 191 million acres of forest

and grassland under its care. These areas provide multiple benefits to the country, from

traditional commodities such as timber, range, forage, and minerals, to opportunities for

recreation. The Forest Service also provides natural resource management guidance and

assistance to state and private landowners in both rural and urban environments.

Office of the Chief Economist

The Office of the Chief Economist advises the Secretary of Agriculture on the economic

implications of policies and programs affecting the U.S. food and fiber system and rural areas.

This office also oversees the activities of the World Agricultural Outlook Board and the Global

Climate Change Office, among other departmental activities. The World Agricultural Outlook

Board approves the Grain Transportation Prospects report (see description under Agricultural

Marketing Service).

OTHER FEDERAL ENTITIES

The transportation sectors of interests to the constituencies of five additional federal entities are

summarized in Table F-7.

Table F-7 Interests in WIST Transportation Sectors of Constituencies for Other Federal Entities

Transportation Sectors of Constituencies

Federal Entity Road Rail MTS Pipeline Transit

Airport

Ground Ops

Environmental Protection Agency X X

Federal Emergency Management Agency X X X

National Aeronautics and Space Administration X X X

Nuclear Regulatory Commission X X X

U.S. Postal Service X X X

Environmental Protection Agency

The mission of the U.S. Environmental Protection Agency (EPA) is to protect human health and

safeguard the natural environment—air, water, and land—upon which life depends. The EPA

ensures that environmental protection is an integral consideration in U.S. policies concerning
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natural resources, human health, economic growth, energy, transportation, agriculture, industry,

and international trade. The EPA also ensures that human health and safeguarding the

environment are considered in establishing environmental policy.

Air quality is a major responsibility for the EPA. Coming from many different sources, air

pollution threatens health, damages the environment, and causes haze that reduces visibility in

urban areas, wilderness areas, and national parks. Under the Clean Air Act, EPA sets limits on

how much of a pollutant is allowed in the air anywhere in the United States.

Water is essential for life, and pollution of water has a serious impact on all living creatures.

Water pollution can negatively affect the use of water for drinking, household needs, recreation,

fishing, transportation, and commerce. The EPA enforces federal clean water and safe drinking

water laws, provides support for municipal wastewater treatment plants, and takes part in

pollution prevention efforts aimed at protecting watersheds and sources of drinking water. It

carries out both regulatory and voluntary programs to fulfill its mission to protect the nation's

waters.

An example of EPA’s role in establishing environmental policy is the collaborative process for

transporting nuclear waste from weapons production facilities to a deep earth disposal site in

New Mexico. Initially, the EPA certified that the DOE site in New Mexico meets standards to

protect public health and the environment from the harmful effects of radiation exposure and

contamination. This EPA decision allows DOE to begin disposing of radioactive waste in the site

once all other applicable health and safety standards have been met.

Next, the DOT is responsible for working with individual states to establish the surface routes

that will be used to transport waste to the disposal site. Then the NRC regulates the

transportation of nuclear waste, including the safety of the containers used to transport waste to

the disposal site.

The New Mexico Environment Department is responsible for issuing and enforcing waste

disposal permits relating to the type of waste to be disposed of at this site. The New Mexico

Radioactive Waste Task Force administers the state's safe transportation program for the site.

Finally, the DOE is responsible for developing the site and its day-to-day management.

Federal Emergency Management Agency

Since its founding in 1979, the mission of the Federal Emergency Management Agency (FEMA)

has been to reduce loss of life and property and protect our nation's critical infrastructure from all

types of hazards through a comprehensive, risk-based, emergency management program of

mitigation, preparedness, response, and recovery. FEMA is an independent agency of the federal

government, reporting to the President. Two primary areas of FEMA responsibility with

implications for WIST are evacuation management and response to nuclear, biological or

chemical (including hazardous materials, or HAZMAT) incidents. Evacuation management

includes the movement of people and resources such as emergency equipment and relief supplies

in response to major catastrophic events such as earthquakes, flooding, fires, and hurricanes.

Response to nuclear, biological, or chemical events includes evacuation of people and care for
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victims. To respond effectively to these events, FEMA incorporates atmospheric transport and

diffusion information into emergency decision-making processes.

National Aeronautics and Space Administration

The missions of the National Aeronautics and Space Administration (NASA) are to advance and

communicate scientific knowledge and understanding of the Earth, the solar system, and the

universe; to use the environment of space for research; to explore, use, and enable the

development of space for human and robotic endeavors in science and commerce; and to

research, develop, verify, and transfer advanced aeronautics, space, and related technologies.

Goddard Space Flight Center

Goddard Space Flight Center is one of nine field centers operated by NASA. One of this center’s

many responsibilities is the safe and efficient movement of spacecraft, vehicles, and equipment

between Goddard and other facilities, especially the launch facilities. The most prevalent mode

of transportation is by truck from the center to either the final destination or an aerial port, such

as Andrews Air Force Base, where the cargo can be air shipped. Transportation operations at

Goddard are highly dependent on weather conditions, and adverse conditions may delay or

cancel an activity (see the Roadway and Marine Transportation System WIST Templates).

Kennedy Space Center

The John F. Kennedy Space Center is NASA’s Spaceport Technology Center and the center for

launch and payload processing systems. It is also NASA’s lead center for acquisition and

management of expendable launch vehicle services and payload carriers. Located at Cape

Canaveral Spaceport in Florida, this NASA center manages the checkout, launch, and landing of

the Space Shuttles and their payloads. It is also the starting point of all U.S. human space flights.

Stennis Space Center

The John C. Stennis Space Center is NASA’s center for rocket propulsion testing and Earth

science applications. It is NASA’s primary center for testing and flight-certifying rocket

propulsion systems for the Space Shuttle Program and future generations of space vehicles. The

Stennis Space Center also provides substantial support in remote sensing, which is valuable for

remote observation of weather and related conditions relevant to WIST user needs.

Nuclear Regulatory Commission

The Nuclear Regulatory Commission (NRC) is an independent agency whose mission is to

ensure adequate protection of the public health and safety, the common defense and security, and

the environment by regulating the use of nuclear materials. In addition to regulating nuclear

energy facilities and radioactive materials in the United States, the NRC regulates the transport,

storage, and disposal of nuclear materials and nuclear wastes. It authorizes the use,

transportation, and storage of spent nuclear fuel after determining that the proposed activities are

consistent with the regulatory framework and level of risk.
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From a transportation perspective, the NRC approves the packaging designs for high activity

radioactive materials and spent nuclear fuel. It also approves the quality assurance programs for

use of these packages. It coordinates and develops guidance with other U.S. government and

international agencies on storage and transportation policy and safety issues. When necessary,

the NRC provides technical support for incident and emergency response.

U.S. Postal Service

The mission of the Postal Service is to bind the nation together through the correspondence of

the people, provide access in all communities, and offer prompt, reliable postal services at

uniform prices. Postal services are an essential government function, one that has been integral to

building the nation. The delivery of postal services has supported development of national

transportation and communication infrastructures. It has linked urban and rural economies and

has led to the creation of the country's physical address system. Transportation responsibilities of

the Postal Service range from long-haul interstate movements to local delivery. An observation

made at the WIST II Symposium is that the nationwide daily distribution of Postal Service

vehicles provides an excellent opportunity to use them as mobile meteorological sensing

platforms dispersed throughout the nations highway and road systems.
COMMITTEE FOR ENVIRONMENTAL SERVICES,

OPERATIONS AND RESEARCH NEEDS

MR. DONALD WERNLY, Tri-Chairperson

National Oceanic and Atmospheric Administration

Department of Commerce

COL. LAWRENCE KEY, USAF, Tri-Chairperson

Department of Defense

CAPT KATHY SHIELD, USN, Tri-Chairperson

Department of Defense

MR. ROBERT STEFANSKI

Department of Agriculture

MR. REGINALD LAWRENCE

National Oceanic and Atmospheric Administration

Department of Commerce

CDR SCOTT STEADLY, USN

Department of Defense

MR. RICKEY PETTY

Department of Energy

MR. LEWIS T. MOORE

Department of the Interior

MR. KEVIN BROWN

Federal Aviation Administration

Department of Transportation

MR. PAUL PISANO

Federal Highway Administration

Department of Transportation

MS. CHARLENE M. WILDER

Federal Transit Administration

Department of Transportation

DR. JONATHAN M. BERKSON

U.S. Coast Guard

Department of Transportation

MR. PAUL BRYANT

Federal Emergency Management Agency

MR. DONALD EICK

National Transportation Safety Board

MS. LETA BROWN

Nuclear Regulatory Commission

MS. MARY M. CAIRNS, Executive Secretary

Office of the Federal Coordinator for

Meteorological Services and Supporting Research

JOINT ACTION GROUP FOR WEATHER INFORMATION

FOR SURFACE TRANSPORTATION

MR. BRADLEY RIPPEY

Department of Agriculture

MR. MICHAEL A.TOMLINSON

National Oceanic and Atmospheric Administration

Department of Commerce

MR. TERRANCE TIELKING

U.S. Navy

Department of Defense

MAJ. JAMES COTTURONE, USAF

U.S. Transportation Command

Department of Defense

MR. RICKEY C. PETTY

Department of Energy

MR. LEWIS T. MOORE

Department of the Interior

MR. PAUL PISANO

Federal Highway Administration

Department of Transportation

MR. DONALD PLOTKIN

Federal Railroad Administration

Department of Transportation

MR. WILLIAM WIGGINS

Federal Transit Administration

Department of Transportation

MR. MICHAEL ROSSETTI

Research and Special Programs Administration

Department of Transportation

DR. JONATHAN M. BERKSON

U.S. Coast Guard

Department of Transportation

MR. JOHN GAMBEL

Federal Emergency Management Agency

DR. RAMESH KAKAR

National Aeronautics and Space Administration

MR. DONALD E. EICK

National Transportation Safety Board

MS. LETA A. BROWN

Nuclear Regulatory Commission

MS. FAYE ARVONIO

U.S. Postal Service

MR. BLAINE K. TSUGAWA, Executive Secretary

Office of the Federal Coordinator for

Meteorological Services and Supporting Research

Rear Cover Photo Credits (clockwise from top left)

Truck on snowy road: OFCM photo library

Snowy Interstate: Courtesy, University of North Dakota

Aircraft de-icing: Courtesy, United Airlines

Tornado along highway: Courtesy, Dave Williams, Wichita Eagle

Trans-Alaska pipeline: Courtesy, Office of Pipeline Safety, Department of Transportation

Long Beach Harbor: Courtesy, Port of Long Beach, California