Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296

Coordinated Freeway and Arterial

Operations Handbook

PUBLICATION NO. FHWA-HRT-06-095 MAY 2006
FOREWORD 

Transportation agencies are realizing the importance of managing and operating transportation 

facilities to make the most of their existing capacity. Many agencies are successfully using traffic 

management strategies to operate freeways and arterials more efficiently. However, not many 

agencies are operating freeways and adjacent arterials together in a coordinated manner that 

treats these roadways as an interconnected traffic operations corridor rather than separate 

entities. 

The purpose of the Coordinated Freeway and Arterial Operations Handbook is to provide 

direction, guidance, and recommendations on how to proactively and comprehensively 

coordinate freeway and adjacent arterial street operations together as a single, interconnected 

corridor. Agencies that make this shift from an agency perspective to systemwide perspective not 

only optimize traffic conditions on the overall corridor but on their own facilities as well. 

The intended target audiences for this report are transportation professionals involved in the 

management, planning, engineering, design, and operations of traffic on freeway and arterial 

facilities. This includes managers, supervisors, planners, engineers, designers, and traffic 

operations staff. 

Toni Wilbur 

Director, Office of Operations Research 

 and Development 

Notice 

This document is disseminated under the sponsorship of the U.S. Department of Transportation 

in the interest of information exchange. The U.S. Government assumes no liability for the use of 

the information contained in this document. This report does not constitute a standard, 

specification, or regulation. 

The U.S. Government does not endorse products or manufacturers. Trademarks or 

manufacturers' names appear in this report only because they are considered essential to the 

objective of the document. 

Quality Assurance Statement 

The Federal Highway Administration (FHWA) provides high-quality information to serve 

Government, industry, and the public in a manner that promotes public understanding. Standards 

and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its 

information. FHWA periodically reviews quality issues and adjusts its programs and processes to 

ensure continuous quality improvement.
Form DOT F 1700.7 (8-72) 

1. Report No.

FHWA-HRT-06-095 

2. Government Accession No. 3. Recipient’s Catalog No. 

4. Title and Subtitle 5. Report Date

May 2006 

Coordinated Freeway And Arterial Operations Handbook 6. Performing Organization 

Code 

7. Authors

Thomas Urbanik, David Humphreys, Brian Smith, and Steve Levine 

8. Performing Organization 

Report No. 

 

9. Performing Organization Name and Address

Science Applications International Corporation (SAIC) 

1710 SAIC Drive 

M/S T1-12-3 

McLean, VA 22102 

10. Work Unit No. (TRAIS) 

 

11. Contract or Grant No.

DTFH61-01-C-00180 

12. Sponsoring Agency Name and Address

Office of Operations Research and Development 

Federal Highway Administration 

6300 Georgetown Pike 

McLean, VA 22101-2296 

13. Type of Report and Period 

Covered

 Final Report 

June 2002—May 2006 

14. Sponsoring Agency Code

15. Supplementary Notes

Mr. James Colyar, Contracting Officer’s Task Manager 

16. Abstract 

Managing and operating freeways and adjacent arterials in a proactive and comprehensive manner, from a system 

user’s perspective, is a major step toward operating all modes of the transportation system at maximum efficiency. 

The focus of this guide is on operating freeways and adjacent arterials together in a coordinated manner that treats 

these roadways not as separate entities, but as an interconnected traffic operations corridor. 

 

The purpose of this document is to provide direction, guidance, and recommendations for transportation managers, 

engineers, and planners on how to proactively and comprehensively coordinate freeway and arterial street 

operations. 

17. Key Words

arterial operations, freeway operations, regional 

operations, corridor operations, corridor management, 

traffic operations corridor 

18. Distribution Statement 

No restrictions. This document is available to the 

public from: The National Technical Information 

Service, Springfield, VA 22161. 

19. Security Classif. (of this 

report) 

Unclassified 

20. Security Classif. (of this 

page) 

Unclassified 

21. No of Pages

152 

22. Price 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized. 
ii 

SI* (MODERN METRIC) CONVERSION 

FACTORS APPROXIMATE CONVERSIONS TO SI UNITS 

SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL 

LENGTH 

in inches 25.4 millimeters mm 

ft feet 0.305 meters m 

yd yards 0.914 meters m 

mi miles 1.61 kilometers km 

AREA 

in2 square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m2

yd2 square yard 0.836 square meters m2

ac acres 0.405 hectares ha 

mi2 square miles 2.59 square kilometers km2

VOLUME 

fl oz fluid ounces 29.57 milliliters mL 

gal gallons 3.785 liters L 

ft3 cubic feet 0.028 cubic meters m3

yd3 cubic yards 0.765 cubic meters m3

NOTE: volumes greater than 1000 L shall be shown in m3 

MASS 

oz ounces 28.35 grams g 

lb pounds 0.454 kilograms kg 

T short tons (2000 lb) 0.907 megagrams (or "metric 

ton") 

Mg (or "t") 

TEMPERATURE (exact degrees) o

F Fahrenheit 5 (F-32)/9 or (F-32)/1.8 Celsius oC 

ILLUMINATION 

fc foot-candles 10.76 lux lx 

fl foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS 

lbf poundforce 4.45 newtons N 

lbf/in2 poundforce per square inch 6.89 kilopascals kPa 

APPROXIMATE CONVERSIONS FROM SI UNITS 

SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL 

LENGTH 

mm millimeters 0.039 inches in 

m meters 3.28 feet ft 

m meters 1.09 yards yd 

km kilometers 0.621 miles mi 

AREA 

mm2 square millimeters 0.0016 square inches in2

m2 square meters 10.764 square feet ft2

m2 square meters 1.195 square yards yd2

ha hectares 2.47 acres ac 

km2 square kilometers 0.386 square miles mi2

VOLUME 

mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m3 cubic meters 35.314 cubic feet ft3

m3 cubic meters 1.307 cubic yards yd3

MASS 

g grams 0.035 ounces oz 

kg kilograms 2.202 pounds lb 

Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T 

TEMPERATURE (exact degrees) 

o

C Celsius 1.8C+32 Fahrenheit oF 

ILLUMINATION 

lx lux 0.0929 foot-candles fc 

cd/m2 candela/m2 0.2919 foot-Lamberts fl 

FORCE and PRESSURE or STRESS 

N newtons 0.225 poundforce lbf 

kPa kilopascals 0.145 

poundforce per square 

inch lbf/in2

*SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 

4 of ASTM E380. 
iii

TABLE OF CONTENTS 

1 Introduction....................................................................................................................... 1

1.1 Purpose.......................................................................................................................... 1 

1.2 The Underlying Problem............................................................................................... 2 

1.3 The Challenge of Coordinated Operations ................................................................... 4 

1.4 What is Coordinated Freeways and Arterials Operations?........................................... 4 

1.4.1 The Need for CFA Operations............................................................................ 5 

1.4.2 Creating a Coordinated Operations Mindset ...................................................... 5 

1.4.3 When To Implement CFA Operations................................................................ 6 

1.5 Benefits of CFA Operations.......................................................................................... 7 

1.6 Document Organization................................................................................................ 9 

2 Planning for Coordinated Operation of Traffic on Freeways and Arterials ............ 11

2.1 Purpose........................................................................................................................ 11 

2.2 Introduction................................................................................................................. 11 

2.3 Regional-Level Planning and Coordination................................................................ 12 

2.3.1 Developing a Regional Corridor Traffic Management Plan............................. 16 

2.4 Corridor-Level Planning and Coordination ................................................................ 17 

2.4.1 Getting Started .................................................................................................. 19 

2.4.2 Decisionmaking ................................................................................................ 20 

2.4.3 Implementation ................................................................................................. 21 

2.4.4 Continuous Improvement ................................................................................. 22 

2.5 Summary..................................................................................................................... 22 

3 A Framework For Coordinated Operations in a Corridor......................................... 23

3.1 Purpose........................................................................................................................ 23 

3.2 Introduction................................................................................................................. 23 

3.3 Step 1: Problem Identification .................................................................................... 24 

3.4 Step 2: Institutional Considerations............................................................................ 26 

3.4.1 Identify Corridor Stakeholders ......................................................................... 27 

3.4.2 Corridor Champions ......................................................................................... 30 

3.5 Step 3: Goals, Objectives, and Performance Measures .............................................. 31 

3.6 Step 4: Corridor Concept of Operations ..................................................................... 33 

3.7 Step 5: Corridor Scenarios and Operations Strategies................................................ 36 
iv

3.7.1 Traveler Information......................................................................................... 38 

3.7.2 Traffic Management and Control ..................................................................... 40 

3.7.3 Shared Information and Resources................................................................... 43 

3.8 Step 6: Evaluation and Selection of Strategies ........................................................... 44 

3.9 Step 7: Corridor Implementation Plan ........................................................................ 45 

3.10 Step 8: Design and Development................................................................................ 46 

3.11 Step 9: Deployment..................................................................................................... 52 

3.12 Step 10: Operations and Maintenance ........................................................................ 52 

3.13 Step 11: Continuous Improvement ............................................................................. 54 

3.14 Summary..................................................................................................................... 55 

4 Applying CFA Operations to Four Opportunity Areas .............................................. 57

4.1 Purpose........................................................................................................................ 57 

4.2 Introduction................................................................................................................. 57 

4.3 Traffic Incident Management ..................................................................................... 57 

4.3.1 Problem Identification ...................................................................................... 58 

4.3.2 Institutional Considerations .............................................................................. 59 

4.3.3 Goals, Objectives, and Performance Measures ................................................ 61 

4.3.4 Corridor Concept of Operations ....................................................................... 62 

4.3.5 Corridor Scenarios and Operations Strategies.................................................. 64 

4.3.6 Evaluation and Selection of Strategies ............................................................. 65 

4.3.7 Corridor Implementation Plan .......................................................................... 67 

4.3.8 Design and Development.................................................................................. 68 

4.3.9 Deployment....................................................................................................... 71 

4.3.10 Operations and Maintenance ............................................................................ 71 

4.3.11 Continuous Improvement ................................................................................. 71 

4.4 Work Zone Management ............................................................................................ 72 

4.4.1 Problem Identification ...................................................................................... 72 

4.4.2 Institutional Considerations .............................................................................. 73 

4.4.3 Goals, Objectives, and Performance Measures ................................................ 75 

4.4.4 Corridor Concept of Operations ....................................................................... 76 

4.4.5 Corridor Scenarios and Operations Strategies.................................................. 78 

4.4.6 Evaluation and Selection of Strategies ............................................................. 80 

4.4.7 Corridor Implementation Plan .......................................................................... 82 

4.4.8 Design and Development.................................................................................. 82 

4.4.9 Deployment....................................................................................................... 83 

4.4.10 Operations and Maintenance ............................................................................ 84 
v

4.4.11 Continuous Improvement ................................................................................. 84 

4.5 Planned Special Events Management ......................................................................... 84 

4.5.1 Problem Identification ...................................................................................... 87 

4.5.2 Institutional Considerations .............................................................................. 87 

4.5.3 Goals, Objectives, and Performance Measures ................................................ 90 

4.5.4 Corridor Concept of Operations ....................................................................... 90 

4.5.5 Corridor Scenarios and Operations Strategies.................................................. 92 

4.5.6 Evaluation and Selection of Strategies ............................................................. 94 

4.5.7 Corridor Implementation Plan .......................................................................... 95 

4.5.8 Design and Development.................................................................................. 95 

4.5.9 Deployment....................................................................................................... 97 

4.5.10 Operations and Maintenance ............................................................................ 97 

4.5.11 Continuous Improvement ................................................................................. 98 

4.6 Day-To-Day or Recurring Operations ........................................................................ 98 

4.6.1 Problem Identification ...................................................................................... 99 

4.6.2 Institutional Considerations .............................................................................. 99 

4.6.3 Goals, Objectives, and Performance Measures .............................................. 100 

4.6.4 Corridor Concept of Operations ..................................................................... 101 

4.6.5 Refinement of Scenarios and Improvement Strategies................................... 102 

4.6.6 Evaluation and Selection of Strategies ........................................................... 104 

4.6.7 Corridor Implementation Plan ........................................................................ 105 

4.6.8 Design and Development................................................................................ 106 

4.6.9 Implementation ............................................................................................... 106 

4.6.10 Operations and Maintenance .......................................................................... 106 

4.6.11 Continuous Improvement ............................................................................... 106 

4.7 Summary................................................................................................................... 107 

5 Supporting Technologies and ITS Elements .............................................................. 109

5.1 Purpose...................................................................................................................... 109 

5.2 Introduction............................................................................................................... 109 

5.3 Information Sharing.................................................................................................. 109 

5.4 Technology and ITS Elements.................................................................................. 111 

5.4.1 Traffic Data Collection Systems..................................................................... 112 

5.4.2 Traffic Control Systems.................................................................................. 114 

5.4.3 Information Dissemination Systems............................................................... 115 

5.4.4 Communications Networks and Systems ....................................................... 116 

5.4.5 Data Analysis Systems.................................................................................... 117 
vi

5.4.6 ITS Architecture and Standards...................................................................... 117 

5.5 Summary................................................................................................................... 118 

6 Examples of CFA Operations ...................................................................................... 121

6.1 Example 1: Developing Incident Management Route Diversion Strategies in Northern 

Virginia ................................................................................................................................. 121 

6.1.1 Problem Identification .................................................................................... 121 

6.1.2 Institutional Considerations ............................................................................ 122 

6.1.3 Goals, Objectives, and Performance Measures .............................................. 123 

6.1.4 Corridor Concept of Operations ..................................................................... 123 

6.1.5 Corridor Scenarios and Operations Strategies................................................ 123 

6.1.6 Evaluation and Selection of Strategies ........................................................... 124 

6.1.7 Corridor Implementation Plan ........................................................................ 127 

6.1.8 Design and Development................................................................................ 127 

6.1.9 Deployment..................................................................................................... 128 

6.1.10 Operations and Maintenance .......................................................................... 128 

6.1.11 Continuous Improvement ............................................................................... 128 

6.1.12 Example Summary.......................................................................................... 128 

6.2 Example 2: Leveraging ITS Technologies to Enhance CFA Operations ................. 128 

6.2.1 Major Incident Without Leveraging ITS Technologies.................................. 129 

6.2.2 Major Incident With Leveraging ITS Technologies....................................... 131 

6.3 Summary................................................................................................................... 133 

Appendix: ITS Technology Inventory, Needs Assessment, and Integration....................... 135

References.................................................................................................................................. 143
vii

LIST OF FIGURES 

Figure 1. Chart. Increase in congestion in the past 20 years in the largest U.S. cities. ...................3 

Figure 2. Chart. Sources of traffic congestion. ................................................................................3 

Figure 3. Chart. Relationship between regional and local functions. ............................................13 

Figure 4. Chart. Elements of regional collaboration and coordination..........................................13 

Figure 5. Chart. Example of integrating regional and local processes. .........................................15 

Figure 6. Chart. The coordinated freeway and arterial (CFA) operations framework. .................24 

Figure 7. Chart. Questions addressed by a concept of operations document. ...............................34 

Figure 8. Photo. Sample DMS message.........................................................................................39 

Figure 9. Photo. Uncoordinated arterial signals can cause reduced effectiveness of ramp 

metering on freeways.............................................................................................................42 

Figure 10. Photo. Dynamic lane assignment on an arterial. ..........................................................43 

Figure 11. Photo. A freeway TMC collects and shares information from many sources..............44 

Figure 12. Chart. Example of development of corridor operations plans......................................49 

Figure 13. Chart. Example of development of corridor operations procedures.............................50 

Figure 14. Chart. Example of identifying field equipment responsibilities...................................51 

Figure 15. Photo. Traffic signal maintenance crew at work..........................................................53 

Figure 16. Chart. Example of operations plans and procedures for incident management 

scenarios.................................................................................................................................70 

Figure 17. Chart. Integration of planned special event management phases.................................86 

Figure 18. Chart. Stakeholders who may be involved in planned special events. ........................88 

Figure 19. Chart. Traveler interface with technology systems. ...................................................111 

Figure 20. Drawing. Map of project area.....................................................................................122 

Figure 21. Chart. Off-peak strategy alternatives..........................................................................125 

Figure 22. Chart. Peak strategy alternatives. ...............................................................................126 

Figure 23. Chart. A major urban area situated along a navigable river with multiple 

east-west bridge crossings....................................................................................................130 
viii

LIST OF TABLES 

Table 1. Characteristics of a coordinated operations mindset. ........................................................6 

Table 2. Benefits of CFA operations. ..............................................................................................8 

Table 3. Overview of document chapters. .....................................................................................10 

Table 4. Candidate stakeholder organizations or agencies. ...........................................................29 

Table 5. Example of goals and objectives for corridor operations. ...............................................32 

Table 6. Developing detailed corridor operations scenarios..........................................................37 

Table 7. Example objectives for work zones.................................................................................75 

Table 8. Example operations strategies for work zones. ...............................................................79 

Table 9. Example corridor operations plan for freeway work zone. .............................................83 

Table 10. Example strategies for mitigating special event congestion..........................................93 

Table 11 Special event operations plan checklist. .........................................................................96 

Table 12. Example objectives for day-to-day operations. ...........................................................101 

Table 13. Example strategies for day-to-day operations. ............................................................103 
1

1 INTRODUCTION 

1.1 Purpose 

Traffic congestion is increasing significantly throughout the United States. Congestion is 

increasing in rural areas and urban areas, in small cities, and large cities. Further, the 

transportation community realizes there is no one proven way to fix the congestion problem and 

that a comprehensive approach of multiple congestion-reducing strategies is needed. One of 

these strategies is to operate the existing roadway system more efficiently or, in other words, to 

get more out of what already exists. 

Proactively managing and operating existing freeways and 

adjacent arterials in a comprehensive manner, from a 

transportation system user’s perspective, are major steps toward 

operating all modes of the transportation system at maximum 

efficiency. However, this handbook is not just about using system 

management strategies to operate freeways and arterials more 

efficiently; rather, the focus of this guide is on operating freeways and adjacent arterials together

in a coordinated manner that treats these roadways not as separate entities, but as an 

interconnected traffic operations corridor. This is how transportation users view and use these 

roadways. Users will often, for example, divert from a freeway to an adjacent arterial during a 

freeway incident because they realize the adjacent arterial will get them to their destination more 

efficiently in this scenario. 

The purpose of this handbook is to provide direction, guidance, and recommendations for 

transportation managers, engineers, technicians, and planners on how to proactively and 

comprehensively coordinate freeway and arterial street operations. There are many guidance 

documents on how to manage and operate transportation facilities individually, but this 

document is a first-of-a-kind because it focuses on how to coordinate the operations of different 

facility types that are typically operated by separate organizational entities with separate 

missions. To support the goal and purpose of this document, specific objectives include: 

 

 Discuss the benefits of coordinated freeways and arterials (CFA) operations and why taking a 

coordinated approach benefits both users and managers of the transportation system. 

 Explain how to take a broad, regional view of coordinating freeway and arterial streets before 

making plans and procedures for specific corridors. 

 Describe how to develop a regional corridor management plan to support a broad, regional 

view of coordinated corridor operations. 

 Describe a framework for planning and implementing coordinated plans and procedures for a 

single freeway and arterial corridor. 

 Address the institutional challenges inherent in coordination and suggest ways to overcome 

these barriers. 

 Define the range of possible operations strategies that can be used to address CFA operations, 

such as traveler information, traffic management and control, and information and resource 

sharing. 

The purpose of this document is 

to provide direction, guidance, 

and recommendations on how to 

proactively and comprehensively 

coordinate freeway and arterial 

street operations. 
2

 Discuss how to package the operations strategies into operations plans and procedures for 

different response scenarios. 

 Illustrate how coordinated plans and procedures can be developed for specific opportunities 

for coordination, including traffic incident management, work zone management, planned 

special events management, and day-to-day operations. 

 Discuss the intelligent transportation system (ITS) technologies and components used to 

support coordinated operations and how to perform an ITS needs assessment to support the 

development of specific coordinated plans and procedures. 

 Present a hypothetical application of state-of-the-art ITS in a regional area with multiple 

corridors to demonstrate real-time dynamic CFA operations. 

1.2 The Underlying Problem 

Demand for highway travel by Americans continues to grow as the population increases, 

particularly in metropolitan areas. The effects of congestion are captured in a number of 

measures and perceptions, including visible and consistent roadway congestion, the loss of 

personal and professional time, environmental degradation, and general traveler frustration—in 

essence, a reduction in overall mobility and accessibility. Figure 1 illustrates how congestion has 

grown in numerous ways to affect more people at a greater rate for longer periods of time. 

While traffic congestion can be easily seen and measured, the underlying causes of traffic 

congestion are more difficult to discern. Recent research has determined these “root” causes on a 

national scale, as shown in figure 2. These percentages shown are national averages, so the 

percentages for an individual metropolitan area may vary depending on the local conditions. 

Delays (resulting from congestion) at particular locations in a transportation network are 

certainly aggravating to those using the system; but these delays are part of a much larger picture 

of how a transportation system allows people and goods to move around a metropolitan area. The 

consequences of congestion are much more serious to a community. For example:(1)

 Local Traffic Impacts—Traffic bypassing congested conditions on a freeway can have large 

and unwanted impacts on local businesses and residential neighborhoods. 

 Economic Growth—Efficient transportation access to employment and shopping sites is an 

important consideration to business and developers when considering expansion opportunities. 

 Quality-of-Life—Long, frustrating commutes are contributors to human stress. In addition, this 

stress can be heightened when dealing with traffic jams and delays within neighborhoods after 

a long commute home from work. Traffic problems and congestion are an important 

characteristic of quality of life to many people. 

 Environmental Quality—Congested road conditions can have a detrimental effect on the 

environment, in particular air quality. Making improvements to the transportation system or 

trying to change travel behavior has been an important objective of those wanting to improve 

environmental quality. 
3

Figure 1. Chart. Increase in congestion in the past 20 years in the largest U.S. cities.(2)

Figure 2. Chart. Sources of traffic congestion.(3)

Bottlenecks

40%

Traffic Incidents

25%

Work Zones

10%

Bad Weather

15%

Poor Signal Timing

5%

Special Events

5%
4

1.3 The Challenge of Coordinated Operations 

The surface transportation system has been operated historically by separate entities with specific 

missions, goals, and objectives. These entities may have varying authority that may be either 

very limited or rather broad. In addition, responsibilities may overlap. Typically, the State 

government manages and operates freeway facilities and most major arterials and city or county 

governments manage and operate secondary arterials, collectors, and local streets. Furthermore, 

some functions, such as policing or emergency services, typically do not correspond with the 

agency that operates the roadway facilities. The result of this complex institutional arrangement 

is that the transportation system is operated from a single agency or facility-specific perspective, 

resulting in less than optimal operations when viewed from a systemwide perspective. It is this 

suboptimal systemwide perspective that motorists experience. 

This challenge of operating freeways and adjacent arterial streets from a coordinated, system 

perspective was identified long ago. Many agencies have discussed ways to better coordinate 

their freeways and arterials, but few have actually implemented a comprehensive method for 

doing so. The reasons for this lack of communication and interoperability range from 

institutional barriers to technical challenges. Recent advancements in technology (i.e., 

centralized software systems, high-speed telecommunications, and interoperable ITS devices 

through common standards), coupled with improvements in institutional coordination (i.e., many 

regions now have multi-agency, regional-level ITS and traffic operations working groups), are 

now providing regions with the tools and abilities to create proactive plans and procedures for 

operating freeways and arterial streets in a coordinated manner. While it is a challenge, regions 

may significantly benefit by taking advantage of these advancements in technology and 

institutional collaborations by operating their freeways and arterial streets in a coordinated 

manner. 

1.4 What is Coordinated Freeways and Arterials Operations? 

Coordinated freeways and arterials (CFA) operations is the implementation of policies, 

strategies, plans, procedures, and technologies that enable traffic on freeway and adjacent 

arterials to be managed jointly as a single corridor and not as individual, separate facilities. 

These policies, strategies, etc. should have an end goal of improving the mobility, safety, 

and environment of the overall corridor and not just individual 

facilities. For the purposes of this handbook, a corridor is defined 

as a freeway facility together with adjacent and connecting arterial 

streets that collectively function to move vehicles through a 

geographic area. While the term “corridor” could be applied to 

other facilities and modes of transportation, this handbook is 

designed to focus specifically on freeways and arterial streets. The 

concepts presented in this handbook could apply to corridors in urban, suburban, or rural areas. 

CFA operations are the 

implementation of policies, 

strategies, and so forth that 

manages traffic on freeways and 

adjacent arterials jointly as a 

single corridor and not as 

individual facilities.
5

1.4.1 The Need for CFA Operations 

The operation of freeways and adjacent arterial streets is often closely linked and at visible 

example of how taking a single agency perspective can result in suboptimal, system-level 

performance. While agencies may not manage them as such, motorists view freeways and 

adjacent arterials as an interconnected corridor with multiple routes to travel from their origin to 

destination. 

This point can perhaps be best illustrated with an example of a major incident occurring on a 

State freeway traversing a city. During a major incident, motorists will often attempt to divert 

around the incident via the adjacent city street system. Often, the routes chosen by motorists are 

not the quickest, most efficient alternatives. This “relief valve” effect can easily overwhelm the 

capacity of the local arterials, especially if the city traffic engineer has no advance warning of the 

impending wave of motorists on the local streets. If the city traffic engineer had known about the 

incident when it occurred and had pre-arranged signal timing plans to respond to the incident, the 

impact of the diversion could have been mitigated to some degree. In another freeway incident 

scenario, motorists may not respond to suggestions to divert off 

of the freeway if they do not know the local street system and are 

unaware of good alternate routes. In this case, the freeway is 

entirely overwhelmed while the adjacent arterial streets operate at 

normal conditions, which could be under capacity. As a result, 

this untapped arterial reserve capacity remains unknown to 

frustrated motorists stuck on the freeway. 

These are classic scenarios that occur every day across the nation and highlight the need for CFA 

operations. It is clear these situations represent major delays and inefficiencies to motorists, who 

only look at a system perspective. Agencies that shift from an agency perspective to a system 

perspective not only optimize the entire system, but, in the process, optimize their own roadways 

as well. 

1.4.2 Creating a Coordinated Operations Mindset 

The previous sections documented the need and challenges of coordinating freeway and arterial 

operations; however, “coordinated operations” is easier said than done, and it involves thinking 

differently than the past. Many regions, particularly larger regions, have developed a mature 

system of ITS devices and technologies. Ramp metering systems, incident management systems, 

Transportation Management Centers (TMC), road weather information systems (RWIS), 

dynamic message signs (DMS), detector and video surveillance systems, and traveler 

information systems all represent excellent technologies that help agencies operate their systems 

more efficiently. However, all too often these systems, while operated more efficiently than in 

the past, are still operated separately. They are not coordinated across jurisdictional boundaries. 

Having a coordinated operations mindset involves utilizing operations-enabling technologies and 

procedures in a seamless, comprehensive manner from a user’s standpoint. Table 1 illustrates the 

thinking associated with a coordinated operations mindset, as opposed to the traditional mindset. 

Agencies that shift from an 

agency perspective to a system 

perspective optimize not only the 

overall system but likely their 

own roadways as well. 
6

Table 1. Characteristics of a coordinated operations mindset. 

Thinking... Instead of... 

Coordinated Isolated 

System Jurisdiction 

Customer focus Project focus 

Regional Local 

Proactive Reactive 

Comprehensive Piecemeal 

Real-time information Historical information 

24/7 operations 8/5 operations 

Performance-based Output-oriented 

Source: Adapted from http://www.ops.fhwa.dot.gov/aboutus/opstory.htm.(3)

 

Institutional issues are at the core of having a coordinated operations mindset. All of the 

attributes of a coordinated operations program—policies, plans, procedures, agreements, funding 

mechanisms, strategies, systems and technologies, operational activities, and so on—take place 

within the institutional framework. This institutional foundation for transportation systems is 

multi-agency, multifunctional, and multimodal. Moreover, the authority for transportation 

decisionmaking is dispersed among several levels, or “tiers,” of government (e.g., national, 

statewide, regional, agency, and individual systems), and often among several agencies or 

departments within each governmental level. This institutional disconnect can lead to a 

fragmented delivery system for transportation services, resulting in an agency-specific and/or a 

mode-specific focus rather than an areawide focus that considers the interaction and operation of 

the entire corridor. Gaining consensus across a region on having a coordinated operations 

mindset will help overcome these institutional challenges. 

1.4.3 When To Implement CFA Operations 

In the broadest sense, coordinated operations would be beneficial on any corridor that 

experiences congestion, either recurring or nonrecurring. More specifically, there are a number 

of opportunities for coordination of specific corridors. The opportunities relate back to the 

sources of congestion shown in figure 2. The sources of congestion lend themselves to four 

categories of potential CFA congestion mitigation: 

 Traffic incident management. 

 Work zone management. 

 Planned special event management. 

 Day-to-day or recurring operations. 

Each of these categories presents congestion-causing challenges that would benefit by 

coordinating operations on a corridor. Combining corridor management strategies with 

traditional traffic engineering and management approaches will optimize the corridor safety and 

throughput. 
7

A corridor may have a work zone only once every 10 years, but the impact of closing multiple 

lanes or entire roadways with major detours for days at a time can have a large impact on the 

corridor. On the other hand, recurrent congestion occurs very frequently (i.e., every weekday 

peak period), but the impact is typically less than that of a work zone because most motorists are 

aware of the bottlenecks and can make a plan to account for this congestion (i.e., leave work 

earlier or take an alternate route). 

Ideally, determining which corridors are candidates for these opportunities for coordination 

should be made by a consensus of all stakeholders in the region. In the case of work zones and 

special events, these events are known in advance and should be identified early enough to 

adequately plan and implement plans and procedures to support corridor operations. Specific 

guidance on how to develop corridor implementation plans and procedures to mitigate these 

sources of congestion are provided in chapter 4. 

1.5 Benefits of CFA Operations 

Many studies have documented the benefits of transportation systems operations. For example, 

freeway management systems, such as ramp metering and incident management, have been 

shown to reduce traveltimes 20 to 48 percent, increase travel speeds 16 to 62 percent, and 

decrease accident rates 15 to 50 percent. Meanwhile, arterial management systems, such as 

advanced traffic signal systems, have been shown to reduce traveltimes 8 to 15 percent, increase 

travel speeds 14 to 22 percent, and decrease emissions 4 to 13 percent.(4)

However, these benefits are typically for operating freeway and arterial systems independently 

and not in a coordinated manner. Unfortunately, there have been few empirical studies to show 

the benefits of coordinated operations above and beyond isolated operations. Table 2 shows the 

results of a few selected studies that have documented the benefits of coordinating freeway and 

arterial operations. 

As shown in table 2, an empirical study in Scotland showed that coordinating arterial signal 

timing plans, ramp metering plans, and DMS messages during heavy congestion reduced 

corridor traveltime by 13 percent. Three simulation-based studies demonstrated similar results. 
8

Table 2. Benefits of CFA operations. 

Location (Date) Background Impacts 

M-8 Corridor, 

Glasgow, Scotland 

(1997–1998)(5)

Field deployment of adaptive signal 

control, ramp metering, and DMS 

messages to balance traffic loads through 

corridor. 

Traffic volume: no change. 

Traveltime: 13% decrease. 

Anaheim, CA (2000)(6) Simulated deployment of alternative 

corridor operations plans (signal timing 

plans, ramp metering plans, DMS 

messages, route diversion plans) during 

nonrecurring congestion. 

Traveltime: 2–30% 

decrease. 

Stop time: 15–56% 

decrease. 

San Antonio, TX 

(2000)(7)

Simulated deployment of corridor 

operations plans for integrating incident 

management, DMS messages, and signal 

timing plans. 

Freeway management only: 

16.2% delay reduction. 

Integrated freeway and 

arterial management: 19.9% 

delay reduction. 

Seattle, WA (2000)(8) Simulated deployment of integrating 

arterial and freeway advanced traveler 

information systems (ATIS) in north I–5 

corridor. 

Freeway only ATIS: 1.5% 

delay reduction. 

Freeway plus arterial ATIS: 

3.4% delay reduction. 

The Anaheim study tested a comprehensive, coordinated set of corridor operations plans and 

found significant traveltime savings up to 30 percent. The San Antonio study found a more 

modest impact of coordinating freeway and arterial operations: a 16.2 percent delay reduction 

with just freeway incident management was increased to 19.9 percent when incorporating arterial 

management and incident management plans. 

The benefits of coordinated operations may sometimes be difficult to assess quantitatively, yet in 

a corridor where tens of thousands of people commute, a modest decrease in traveltime may 

translate into many quantitative benefits in such areas as: 

 Safety. 

 Mobility and reliability. 

 Quality of life. 

 Environmental effects. 

 Motorist perceptions. 

To a large extent, collisions that occur as a result of stop-and-go-traffic can be reduced if 

congestion within a transportation corridor is effectively mitigated or the efficiency of corridor 

management is improved. On a corridorwide basis, these systemic improvements translate into 

increased safety for drivers. 
9

Although less obvious, there is a known, direct correlation 

between improved traffic operations and environmental 

improvements. First, and perhaps most importantly, is the 

reduction in the amount of emissions released into the 

atmosphere. As average vehicle speeds increase towards the 

posted speed limit, the amount of vehicle pollutants released into 

the atmosphere generally decreases and vehicles operate at a 

more fuel-efficient mode due to a reduction in the stop-and-go behavior associated with 

congestion. 

Coordinated operations of freeway and arterial traffic can result in less easily defined qualitative 

benefits as well. Improved traffic flow, decreased traveltimes, and improved safety all work 

together to ease motorists’ frustration and concerns, casting users’ perception of regional 

transportation officials and agencies in a more positive light. This in turn makes it easier to 

acquire the needed funding to develop, implement, operate, and maintain transportation systems 

within the corridor. 

Perhaps one of the most valuable benefits, however, is that by developing or improving lines of 

communication and coordination between agencies, organizations, and the public, the foundation 

is laid for improved overall understanding of the goals and objectives of each participant in a 

regional coordination effort. This improved understanding is, potentially, the basis for reaching 

long-term, corridorwide or regional transportation goals. 

1.6 Document Organization 

This document consists of 6 chapters. Table 3 gives a short description of each chapter in the 

document. 

Perhaps the biggest benefit of 

coordinated operations is the 

improved communication and 

coordination between agencies, 

from which the benefits of 

working together can far exceed 

those of just corridor operations. 
10

Table 3. Overview of document chapters. 

Chapter Title Description 

1 Introduction 

This chapter describes the purpose and objectives of 

the document and subject area, the definition and 

need for coordinated operations, and how to use this 

document. 

2 

Planning for Coordinated 

Traffic Operations on 

Freeways and Arterials 

This chapter provides a broad view of the planninglevel activities recommended for the successful 

development of CFA operations examined at a 

regional level and a corridor-specific level. 

3 

A Framework for 

Coordinated Operations on a 

Corridor 

This chapter details the recommended 11-step 

framework for the entire life cycle of coordinated 

operations for a specific corridor. 

4 Applying CFA Operations to 

Four Opportunity Areas 

This chapter demonstrates how the corridor-level 

framework can be applied to incident management, 

work zones, special events, and daily recurring 

operations. 

5 Supporting Technologies and 

ITS Elements 

This chapter presents concepts and technologies that 

will enhance the efficiency of coordinated freeway 

and arterial operations. 

6 Examples of CFA Operations 

This chapter presents practical applications of the 

CFA process and demonstrates the potential of ITS 

technology to enhance corridor operations. 

The intended audience of this document is the team of individuals that is involved in or 

responsible for the planning, coordination, management, or operation of traffic on freeway and 

arterial facilities (e.g., managers, supervisors, engineers, planners, or technicians that are 

involved with legislation, policy, program funding, planning, design, project implementation, 

operations, or maintenance). 

This handbook is intended to be an introductory manual to assist practitioners that may be 

involved in or responsible for the advanced planning and management of travel on freeway and 

arterial roadways for different congestion-causing scenarios. It is not intended to serve as a 

detailed technical reference or design guide that addresses all of the details or tasks to be 

performed that are associated with developing specific traffic control plans, designing interfaces 

to exchange information between systems, developing control algorithms, or implementing plans 

to coordinate traffic on and between freeways and surface street roadways. 
11

2 PLANNING FOR COORDINATED OPERATION OF 

TRAFFIC ON FREEWAYS AND ARTERIALS 

2.1 Purpose 

The purpose of this chapter is to provide a broad view of the planning-level activities 

recommended for the successful development of CFA plans and procedures. Many of these 

planning-level activities should take place at a regional level before developing plans and 

procedures for a specific corridor. Collaboration and coordination among regional stakeholders 

on regional-level policies, agreements, operational strategies, and funding priorities will set the 

stage for successful corridor level plans and procedures. In addition, this chapter provides a 

corridor-level framework for the entire life cycle of planning, deploying, and operating plans and 

procedures for coordinated operations on a single corridor. Upon reading this chapter, the reader 

should have a good understanding of the importance and benefits of planning for CFA 

operations. 

This chapter provides a top-down approach to the subject by first focusing on the regional-level 

planning and coordination activities recommended for corridor management and then 

introducing the corridor-level framework for corridor management. This corridor-level 

framework will be explained in more detail in the next chapter, chapter 3. 

2.2 Introduction 

While an agency could make the case for delving right into the development of corridor 

management plans and procedures, this chapter suggests that the chances for success will be 

much higher if some initial planning and coordination is done upfront. Further, the chances for 

success are even higher if this coordination and collaboration is first initiated at a regional level 

before filtering down to planning for a specific corridor. In terms of corridor management, taking 

a regional perspective means developing consensus among regional stakeholders through 

policies, procedures, agreements, strategies, and priorities for the entire region that will expedite 

the development of plans and procedures for individual corridors. 

“Regional operations” means putting the available operations elements together into an 

integrated package that focuses on maximum system performance from the users’ perspective. 

The critical integration elements among the regional stakeholders are:(9) 

 Resource integration. 

 Information exchange. 

 Equipment sharing. 

 Pooled funding. 

 Personnel integration. 

 Systems integration. 

 Institutional integration. 

The next section discusses the planning and coordination activities related to corridor 

management that should be done on a regional level. Section 2.4 introduces a system engineering 
12

framework for systematically developing and operating CFA plans and procedures for an 

individual corridor. The framework will be presented in more detail in the description of the 

corridor level framework in chapter 3. 

2.3 Regional-Level Planning and Coordination 

Today’s realities require recognition of the constraints imposed upon further expansion of the 

highway network, particularly in metropolitan areas, and that maximization of system efficiency 

and system preservation need to become higher priorities. Regional planning for operations is a 

part of this new reality, and it must be assimilated into the broader metropolitan planning process 

undertaken by metropolitan planning organizations. 

While local metropolitan policymaking organizations currently 

exist with their own local agency interactions and relationships, to 

achieve a broader vision of the transportation system requires 

building new processes and procedures with a regional focus. It is 

the regional transportation planning process that brings regional 

collaboration and coordination to bear on operational issues. This process provides a systematic 

approach to improving regional traffic management, a portion of which is corridor traffic 

management. 

 

The first step in developing CFA operations is understanding that a corridor mindset requires a 

regional perspective and function. Figure 3 illustrates how certain functions can only be executed 

with cooperation and collaboration at the regional level, not at the local or individual agency 

level. Local agencies cannot achieve coordinated operations based on their individual actions. 

Examples of regional functions include: 

 Coordination between freeways and arterials operations. 

 Coordination of traffic signals across jurisdictional boundaries. 

 Sharing resources such as DMSs across jurisdictions. 

 Joining traveler information systems among multiple agencies. 

This process provides a 

systematic approach to 

improving regional traffic 

management, a portion of which 

is corridor traffic management. 
13

Figure 3. Chart. Relationship between regional and local functions.(10) 

Regional-level focus provides multi-agency coordination for many aspects of the surface 

transportation system, fostering freeway mobility, arterial mobility, and traveler information. 

Regional coordination is also a primary factor in encouraging multi-agency sharing of data and 

resources. 

Five major elements, shown in figure 4, form a collaboration and coordination framework on 

which to build sustained relationships between all affected agencies and stakeholders and create 

strategies to improve transportation system performance. The framework creates structures 

through which processes occur that result in products (e.g., a regional corridor traffic 

management plan as discussed in the next section). A commitment of resources is implied to 

support initiation and sustaining of regional collaboration and coordination and for implementing 

agreed upon solutions and procedures. The entire effort is motivated by a desire for measurable 

improvement in regional transportation system performance.(11) 

Figure 4. Chart. Elements of regional collaboration and coordination.(11)
14

The objective of the collaboration and coordination framework is to help institutionalize working 

together as a way of doing business among transportation agencies, public safety officials, and 

other public and private sector interests within a region. The framework is therefore appropriate 

for developing a CFA operations program. Depending on the state of operations in the region, 

corridor operations can either build upon an established collaboration and coordination 

framework or the collaboration and coordination framework can be used as an aid to develop the 

interagency partnership necessary for a successful corridor operations program. 

A collaboration and coordination framework is important because existing institutional structures 

create barriers that make collaboration and coordination difficult. These barriers include resource 

constraints, internal stovepipes in large agencies, and the often narrow jurisdictional perspective 

of governing boards. The framework is intended to guide operators and service providers in 

overcoming these institutional barriers by establishing a process that has been shown to be 

successful in facilitating cooperative relationships. 

An example of developing a regional-level structure to overcome these traditional institutional 

limitations is shown in figure 5. This figure is from the Maricopa Association of Governments 

(MAG) Regional Concept of Transportation Operations, which provides the vision and goals for 

regional operations around Phoenix, AZ as well as a high-level view of the initiatives and 

performance improvements that collaboration and coordination may achieve. This figure shows 

the relationship between local and regional functions developed by the MAG for its region and is 

illustrative of how a regional focus was established using existing agencies. Note that a FreewayArterial Operations subcommittee has been established within this structure. This subcommittee 

organizes and coordinates the regional efforts for corridor management with the local agencies. 

Another example of a regional-level structure is a regional operating organization (ROO), which 

consists of traffic operations agencies, transit agencies, law enforcement, elected officials, and 

other operations agencies focused on the operation and performance of a regional transportation 

system. A ROO works to ensure interagency coordination of resources and information across 

jurisdictional boundaries. It builds partnerships and trust among agencies to improve their 

productivity and performance, creating a more responsive system to temporary capacity 

deficiencies. ROO member agencies may, for example, share traffic signal timing plans, 

coordinate planned strategies and resources for managing travel, conduct public outreach, and 

participate in interagency training.
15

Figure 5. Chart. Example of integrating regional and local processes.(10)

Arizona DOT (ADOT),

Department of Public

Safety (DPS), Governor’s Office of Highway Safety 

(GOHS)

ADOT/DPS/GOHS

Executive 

Partnering Team

Freeway Incident 

Management

Regional Concept of 

Transportation Operations (RCTO) Functions:

Function 4: Incident mgmt. practicesFunction 5: Incident debriefing sessionsFunction 9: Tow ing and recovery vehiclesFunction 11: Extraction of Computer Aided Design (CAD) information to Transportation Operations Center (TOC)/511Function 12: On-scene coordination and communicationFunction 13: Emergency vehicles at incident scenes

ADOT TRC

Potential Source of Funding For Pilot Projects

Maricopa Association

Of Governments (MAG)

MAG Transportation

Review Committee (TRC)

MAG ITS Committee

Regional Traffic

Engineering Collaboration

RCTO Functions:

Planning and funding of Regional Traffic Engineering Collaboration. See East Valley/West Valley Traffic Signal Timing Groups for Functions.

Performance Measurement

Data Archiving

Other Local Functions

RCTO Functions: 

Function 1: Ramp metering operations by ADOTFunction 8: Arizona Local Emergency Response Team (ALERT)/Freew ay Service Patrol (FSP) Operations by ADOTFunction 16: Transit notification of incidents (by Valley Metro)

AZTech Executive Committee

AZTech Operations Committee A

Inf

F

RCT

FuninfoConSysFuninfoFundeteFuntime Funinfo

Shared 

Maintenance 

And Resources

RCTO Functions:

Function 21: Maintenance of local systemsFunction 22: Maintenance of regional systemsFunction 23: Maintenance of regional communicationsFunction 24: Costsharing agreements

Freeway Arterial

Operations

RCTO Functions:

Function 14: Freew ay-arterial operations

Center-to-Center

Communications

RCTO Functions: 

Function 25: Center-to-center communications

Emergency Vehicle

Signal Preemption

RCTO Functions:

Function 19: Standards for EVSP

Transit Signal

Priority

RCTO Functions:

Function 20: Transit signal priority

T

C

RC

Funand FunsigFunage

Incident Management

Arterial Incident 

Management

RCTO Functions:

Function 6: Interagency incident response planFunction 15: Arterial Incident Mgmt. ProgramFunction 17: Extraction of CAD information to Local Traffic Management Centers (LTMCs)

East Valley and West

Valley Traffic Signal

Timing Groups

Regional Traffic 

Engineering 

Collaboration

RCTO Functions:

Function 2: Intracitysignal system operationsFunction 3: Intercity signal system operationsFunction 18: Preset signal timing structure

RCTO Functions: 

Performance Measurement Program.

RCTO Functions: 

Function 26: Data archiving system.

LEGEND: Need Identified in RCTO Existing Committee Existin

Arizona DOT (ADOT),

Department of Public

Safety (DPS), Governor’s Office of Highway Safety 

(GOHS)

ADOT/DPS/GOHS

Executive 

Partnering Team

Freeway Incident 

Management

Regional Concept of 

Transportation Operations (RCTO) Functions:

Function 4: Incident mgmt. practicesFunction 5: Incident debriefing sessionsFunction 9: Tow ing and recovery vehiclesFunction 11: Extraction of Computer Aided Design (CAD) information to Transportation Operations Center (TOC)/511Function 12: On-scene coordination and communicationFunction 13: Emergency vehicles at incident scenes

ADOT TRC

Potential Source of Funding For Pilot Projects

Maricopa Association

Of Governments (MAG)

MAG Transportation

Review Committee (TRC)

MAG ITS Committee

Regional Traffic

Engineering Collaboration

RCTO Functions:

Planning and funding of Regional Traffic Engineering Collaboration. See East Valley/West Valley Traffic Signal Timing Groups for Functions.

Performance Measurement

Data Archiving

Other Local Functions

RCTO Functions: 

Function 1: Ramp metering operations by ADOTFunction 8: Arizona Local Emergency Response Team (ALERT)/Freew ay Service Patrol (FSP) Operations by ADOTFunction 16: Transit notification of incidents (by Valley Metro)

AZTech Executive Committee

AZTech Operations Committee A

Inf

F

RCT

FuninfoConSysFuninfoFundeteFuntime Funinfo

Shared 

Maintenance 

And Resources

RCTO Functions:

Function 21: Maintenance of local systemsFunction 22: Maintenance of regional systemsFunction 23: Maintenance of regional communicationsFunction 24: Costsharing agreements

Freeway Arterial

Operations

RCTO Functions:

Function 14: Freew ay-arterial operations

Center-to-Center

Communications

RCTO Functions: 

Function 25: Center-to-center communications

Emergency Vehicle

Signal Preemption

RCTO Functions:

Function 19: Standards for EVSP

Transit Signal

Priority

RCTO Functions:

Function 20: Transit signal priority

T

C

RC

Funand FunsigFunage

Incident Management

Arterial Incident 

Management

RCTO Functions:

Function 6: Interagency incident response planFunction 15: Arterial Incident Mgmt. ProgramFunction 17: Extraction of CAD information to Local Traffic Management Centers (LTMCs)

East Valley and West

Valley Traffic Signal

Timing Groups

Regional Traffic 

Engineering 

Collaboration

RCTO Functions:

Function 2: Intracitysignal system operationsFunction 3: Intercity signal system operationsFunction 18: Preset signal timing structure

RCTO Functions: 

Performance Measurement Program.

RCTO Functions: 

Function 26: Data archiving system.

LEGEND: Need Identified in RCTO Existing Committee Existin
16

2.3.1 Developing a Regional Corridor Traffic Management Plan 

The first step in developing a corridor management plan is to leverage or build on the regional 

planning process. The goal of planning at the regional level is the development of a 

comprehensive plan for coordinating freeway and arterial 

 operations throughout the region. Such a plan, 

developed or supported by key stakeholders in all 

affected agencies, would be more likely to gain the 

approval of key decisionmakers responsible for funding 

decisions in the region. Once funding and resources have been harnessed, plans and procedures 

for specific corridors can be developed. 

The objective of a regional corridor traffic management plan would be to address issues and 

barriers related to coordinating freeway and arterial operations that are best dealt with at a 

regional level before developing and implementing specific plans, strategies, and procedures 

within specific corridors. In other words, it may be possible to solve a host of issues globally for 

an entire region rather than cause unnecessary repetition by addressing the issues individually for 

each specific corridor. 

Operations issues that can be addressed and resolved at a regional level through policies, 

agreements, and plans include: 

 Optimization and coordination of signals between agencies. 

 Optimization and coordination of traffic signals and adjacent ramp meters. 

 Altering freeway ramp meters during freeway and arterial incidents. 

 Altering arterial signal timing during freeway and arterial incidents. 

 Sharing data on incidents and traveler advisories. 

 Sharing DMSs during various events. 

 Developing regional route diversion plans during freeway and arterial incidents. 

In addition to developing common regional-level operations policies, agreements, and plans, a 

regional corridor management plan could identify and address a number of other issues: 

 Establish a regional working group comprised of key stakeholders and a champion to lead the 

group in being responsible for corridor management within the region. 

 Develop the vision, goals, objectives, and performance measures for corridor traffic 

management in the region. 

 Develop a regional corridor management concept of operations to identify high-level policies 

and plans needed to support plans and procedures for individual corridors (see the above bullet 

list for examples). 

 Identify information and resource sharing needs on a regional level (e.g., identifying whether 

local agencies need to access and view freeway detector and closed circuit television (CCTV) 

cameras) for the purpose of corridor traffic management. 

 Propose technology and ITS needs to support corridor traffic management at a regional level 

(e.g., identifying the need for an updated freeway transportation management center (TMC) 

software system that better allows for regional information and resource sharing). 

The first step in developing a corridor 

management plan is to leverage or build 

on the regional planning process. 
17

 Identify and prioritize specific corridors that need corridor-level plans and procedures for CFA 

operations. 

 Develop a plan for budgeting and phasing corridor-level studies and the subsequent design, 

implementation, operation, and maintenance of the individual corridor management plans. 

The process of putting together a regional corridor management plan will be highly dependent 

upon existing programs and relationships among local agencies. Figure 5 in the previous section 

illustrates how one region created a region-based institutional structure that could be readily 

harnessed to develop such a regional corridor management plan. Each region will have to tailor 

their approach to the local institutional relationships and structures. 

While a formal regional-level plan as suggested in this section is not a requirement before 

developing plans and procedures for individual corridors, there are benefits to developing a 

regional plan, such as: 

 Resolving many of the institutional barriers on a regional level before proceeding to 

developing plans for individual corridors. 

 Gaining region-wide consensus on the general approach and planning for corridor 

management in the region. 

 Gaining the support of key decisionmakers responsible for funding decisions in the region. 

 Cost savings through addressing regional operations issues just once rather than multiple times 

when developing plans and procedures for individual corridors. 

 Cost and timesavings by early identification on what policies and agreements will be needed 

before proceeding to develop plans for individual corridors. 

Some smaller regions may determine that the upfront cost of preparing a formal regional corridor 

management plan may outweigh the benefits listed above. For example, a region with one 

corridor that, both in the near- and long-term, would justify CFA plans, may not need a formal 

regional corridor management plan and could proceed directly to developing plans and 

procedures for that individual corridor. 

After developing a regional corridor management plan, the region would have institutional 

structures in place, consensus by regional stakeholders, policies and plans to support corridor 

management, a prioritized list of corridors warranting individual plans, and the resources 

identified to develop and operate individual corridor implementation plans. The next section 

discusses a recommended framework for development and operation of individual corridor 

implementation plans and procedures. 

2.4 Corridor-Level Planning and Coordination 

A process roadmap, or framework, was developed to facilitate the life cycle (planning, design, 

operations, and maintenance) of CFA operations for an individual corridor. This framework is 

recommended for individual corridors after addressing 

regional-level issues identified in section 2.3. Because 

corridor traffic management is typically fragmented due 

to the institutional make up of the agencies involved in 

The framework provides a process to 

overcome the institutional seams that 

inhibit coordination and collaboration.
18

corridor traffic operations, the framework provides a process to overcome the institutional seams 

that inhibit coordination and collaboration. 

The framework is scalable based on the complexity of the corridor and required operations 

strategies. For smaller corridors, some steps may not need to be formally addressed (e.g., a 

formal evaluation of operations strategies may not be necessary when there is only one feasible 

strategy). For larger, more complex corridors, formally going through each step in the framework 

may be necessary to ensure consensus is achieved by stakeholders, to provide a roadmap through 

the entire life cycle of the project, and to help to identify and address major problems before it is 

too late (i.e., already in the implementation phase). 

The coordinated freeways and arterials framework is composed of the following elements (a 

graphical version of the framework is presented in chapter 3): 

 Getting Started: 

o Step 1: Problem identification. 

o Step 2: Institutional considerations. 

o Step 3: Goals, objectives, and performance measures. 

o Step 4: Corridor concept of operations 

 Decisionmaking: 

o Step 5: Corridor scenarios and operations strategies. 

o Step 6: Evaluation and selection of strategies. 

o Step 7: Corridor implementation plan. 

 Implementation: 

o Step 8: Design and development. 

o Step 9: Deployment. 

o Step 10: Operations and maintenance. 

 Continuous improvement: 

o Step 11: Continuous improvement. 

It should be noted that the framework is cyclic, because the process often requires iteration 

between steps to resolve competing issues. For example, an operations strategy may be chosen 

for evaluation. Upon close consideration, the strategy may require more resources than are 

available, resulting in the reconsideration of alternative strategies more consistent with the 

available resources. 

The steps in the framework are grouped into four categories: getting started, decisionmaking, 

implementation, and continuous improvement. The remainder of this section presents a highlevel discussion of each of these four categories. The next chapter, chapter 3, discusses each of 

these steps in more detail. 
19

2.4.1 Getting Started 

Step 1 is to define the problem. This may occur either through a formal performance monitoring 

process that is part of a regional planning process or as the result of an obvious operational 

problem such as traffic backing up onto a freeway due 

 to an arterial traffic signal. The definition of the 

problem in the broadest sense should actually begin 

at the regional planning and coordination stage 

discussed in the previous section. At the regional 

level, problems are identified at a minimal level of 

detail as part of a planning and programming 

function. What may be a problem to one agency may not be a problem to another; therefore, it is 

important to discuss and gain consensus on the extent and severity of the problem to be addressed. 

This is where Step 2 comes in, which is to assess institutional considerations. A CFA framework 

can create a bridge for agency structures to address an identified problem in a manner that all 

affected stakeholders can support. Part of overcoming institutional isolation is establishing a 

structure, such as a working group composed of various representatives from the affected 

agencies, early on to guide the entire process. The structure, whether an ad hoc group or formal 

committee, should consist of the broadest constituency of stakeholders possible. Participants 

should be representative of all agencies and parties involved in the planning, design, operation, 

or maintenance of the plans and procedures (e.g., planners, engineers, traffic managers and 

supervisors, TMC operators, and maintenance personnel), as well as those directly impacted by 

the plans and procedures (e.g., law enforcement, emergency services, transit operators, special 

event centers, and major employers). The size of the group should be commensurate with the 

size and complexity of the project. Overall, the success of the project is a direct result of the 

ability of a variety of institutions, agencies, and affected parties to gain consensus, have regular 

contact through meetings or other communication, and work within the context of other regional 

entities. 

Once the structure for the stakeholders has been agreed upon and developed, it will be their 

responsibility to identify the goals, objectives and performance criteria for the corridor, step 3 in 

the process. Ideally, the goals and objectives established will be directly related to the problems 

identified in the first step. If the problem was identified broadly, it will be the responsibility of 

the stakeholder group to examine the problem and develop a more detailed assessment of its 

nature. The goals will be broad statements of the desired outcome once the problem is resolved. 

The objectives will be specific statements of what will be achieved in support of the goals (e.g., 

to reduce incident-related delays by 10 percent), and the performance measures identified will 

represent specific measurements that will be used to assess the goals and objectives (e.g., 

vehicle-hours of delay during the a.m. peak travel period). Performance measures should include 

metrics that users of the transportation system experience directly, such as traveltime between 

points. 

Step 4 in getting started is to develop a corridor concept of operations. The corridor concept of 

operations is a document, either formal or informal, that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed to help communicate this view to other 

The success of the project is a direct result of 

the ability of a variety of institutions, agencies, 

and affected parties to gain consensus, have 

regular contact through meetings or other 

communication, and work within the context of 

other regional entities. 
20

stakeholders in this process, such as the interested 

public, and to solicit their feedback. The final document 

should describe the goals, objectives, and performance 

measures of the corridor agreed upon by the stakeholder 

group. It should also provide a description of the 

existing corridor conditions, geometrics and traffic control devices, operating practices and 

policies, and ITS technologies and capabilities. It should also describe at a high level the 

operational scenarios (the traffic conditions during a given operational deficiency) when 

strategies, plans, and procedures are needed and the high-level strategies that can address the 

problems during these scenarios. 

2.4.2 Decisionmaking 

Decisionmaking starts with step 5 and requires identification of detailed operations scenarios for 

the corridor, which allows the process to move toward the selection strategies. While an example 

of a high-level scenario may be a full closure of the freeway during an incident, a more detailed 

scenario would be a full closure of the northbound direction of the freeway from Mileposts 15 

through 20 for more than 2 hours. Based on this scenario, a number of operations strategies 

should be identified that may mitigate this potential cause of congestion. The types of strategies 

that are appropriate within a corridor management context include: 

 Traveler information—providing information to travelers through a variety of media, such 

as radio, television, Web sites, kiosks, telephone (511), highway advisory radio (HAR), and 

both fixed and portable DMSs. Most regions use at least one or more of these media, but often 

the information is not coordinated in a corridor- or systemwide perspective. An example of 

providing traveler information from a corridorwide perspective might be setting a DMS on a 

freeway that provides incident information on nearby arterial streets, or an arterial DMS that 

provides freeway congestion information. A proactive approach might include directions for 

alternate routes via DMS or trailblazer signs to guide motorists around an incident or 

bottleneck. 

 Traffic management and control—coordinating traffic management and control devices, 

plans, and procedures is another effective way to optimize travel through a corridor. A 

primary example is coordinating traffic signals and/or ramp meter signals for movement 

throughout the corridor. Local agencies could develop pre-arranged signal timing plans that 

could be implemented quickly in response to freeway incidents. Adjustment plans for adjacent 

ramp meters could also be incorporated into operations plans. Reversible lanes offer capacity 

enhancement if directional movements allow. Vehicle type restrictions during peak periods 

may ease congestion. Suspending toll collection has proven effective on several major 

facilities when inordinate queues have formed. Access control within a corridor is another 

means of traffic management; activating turning restrictions along an arterial during an 

incident and changing ramp meter timing to restrict access, or even temporarily closing a 

ramp, are all examples of operations strategies to control and manage traffic. 

 Shared information and resources—strategies to share information and resources across 

and within agencies can be very simple and effective, yet are often overlooked. Information 

sharing can be as simple as a telephone call, page, or an e-mail from a freeway TMC operator 

to a city engineer to provide incident notification. This notification enables the engineer to 

quickly activate a pre-arranged signal timing operations plan designed to alleviate congestion 

due to an incident. Another efficient strategy that would allow agencies to easily monitor 

The corridor concept of operations is a 

document, either formal or informal, that 

provides a high-level, user-oriented view of 

operations in a specific corridor. 
21

conditions along adjacent roadways is sharing CCTV cameras among agencies. Other 

resources that could be shared include incident response equipment such as service patrols, 

wreckers, or portable DMSs. 

While many strategies may be easily identified, Step 6 is to evaluate and select the most 

appropriate strategies for each scenario. The assessment of strategies can vary from simple, 

pragmatic assessments to detailed traffic microsimulation studies. The method used should be 

appropriate to the complexity of the alternatives and the cost of implementation. The evaluation 

criteria should also be representative of the goals and objectives of the local area. 

The final step in the decisionmaking phase of the CFA operations framework, step 7, is to 

develop a corridor implementation plan, which provides all the information necessary to proceed 

with the implementation phase. The corridor implementation plan may be a formal document 

that represents the sum total of all the work that has been undertaken up to this point, 

summarizing the identified problems; the goals, objectives, and performance measures; the 

corridor concept of operations; and the selected operations strategies for various corridor 

scenarios. When describing operations strategies, details such as capital and operating costs, 

potential programming priorities and scheduling, infrastructure needs in support of the strategies, 

and descriptions of maintenance procedures and costs can help create a valuable blueprint for the 

remainder of the project. 

2.4.3 Implementation 

The implementation phase consists of design and development, deployment, and operations and 

maintenance. Step 8, design and development, translates each of the various projects included in 

the corridor implementation plan into executable project operations plans. Operations plans 

would be developed only at a high level in the corridor implementation plan, while in this step 

the individual operations plans would be fully developed. For example, the corridor 

implementation plan may identify a light diversion signal timing plan as an operations strategy. 

In the design and development stage, the exact signal settings in the timing plan would be 

determined, the specific individual(s) authorized to implement the plan would be identified, and 

details of how the plans would be implemented would be agreed upon. The design of needed 

infrastructure to support the operations strategies, such as deployment of an arterial DMS, would 

also be completed at this stage of the process. Any needed interagency operating agreements 

would also be finalized during this step. 

Step 9, deployment, comprises the construction of infrastructure, signing interagency 

agreements, and “turning on” needed software or communications equipment. There could be 

many factors involved with a multi-agency, multifaceted deployment, so patience and dedication 

is necessary to ensure a successful project. 

Step 10, operations and maintenance, is perhaps the most important in the process. Stakeholders 

whose primary responsibility will be to activate and operate operations plans should be involved 

early in the process of developing operating plans and procedures. These individuals will not 

only provide valuable insight into operations and maintenance processes, but also have a clear 

understanding of the roles and responsibilities of operations and maintenance personnel during 

the various scenarios. They will also be able to ensure that plans are operating at maximum 

efficiency and reliability. 
22

2.4.4 Continuous Improvement 

The continuous improvement process, reflected in step 11, is never ending. As the system is 

being operated and maintained, it must be continually monitored. The monitoring process 

determines whether the actual performance of the system matches the goals and objectives of the 

project. If the system is not solving the problem identified in Step 1, then modifications should 

be made to better address the problem. This is, in effect, another cycle of problem identification, 

identification of improvement strategies, evaluation, prioritization, design, deployment, 

operations, maintenance, and so on. More detail is given in section 3.13 on when iteration 

through the process is necessary, and to which step in the process iteration should occur. Without 

such a process, the corridor (and the overall system) will fail to perform at optimum 

effectiveness and efficiency. 

2.5 Summary 

This chapter presented a broad view of the planning-level activities recommended for the 

successful development of CFA operations. The planning process was examined at a regional 

level and then at a corridor-specific level. It is only after understanding these levels that 

meaningful corridor sensitivity and analysis can be initiated. The CFA framework introduced in 

this chapter, is described in more detail in the next chapter. Utilizing a consistent framework 

insures a repeatable, stepwise process. Thusly, process, appropriate technologies, and deployable 

solutions are the primary focus for the remainder of this document. 
23 

3 A FRAMEWORK FOR COORDINATED OPERATIONS 

IN A CORRIDOR 

3.1 Purpose 

The purpose of this chapter is to expand on the corridor-level framework recommended for 

planning, developing, and operating plans and procedures to support coordinated operation of 

traffic on freeways and arterials. This chapter assumes that the necessary regional-level planning 

has been completed, and now the region is ready to begin planning for coordinated operations on 

specific corridors. Upon completing this chapter, the reader should have a thorough 

understanding of the issues and processes associated with achieving coordinated operation of 

freeways and arterials on a specific corridor through implementation of the steps in the CFA 

framework. 

3.2 Introduction 

The previous chapter made the case that the chances for success in coordinating the operations of 

freeway and arterial streets improve when first taking a broad, regional view of solving some of 

the coordination and institutional issues between agencies. One of the results of this regionallevel planning process is the identification of corridors that 

have operational problems that would benefit from 

CFA operations. The regional-level planning process 

provides sufficient information to move forward to the 

detailed corridor implementation planning process, 

which is the focus of this chapter. 

A process roadmap, or framework, was developed to aid agencies and regions in planning, 

developing, and operating CFA operations for an individual corridor. Figure 6 displays this 

corridor-level CFA operations framework. The 11-step process may at first glance seem complex 

or unnecessary. However, adhering to a process ensures that all planning considerations are 

addressed, and the potential for realizing the noted benefits of this framework are maximized: 

 The steps in the framework cover the entire life cycle of a project, from planning to design to 

operations. All these steps need to be considered by someone at some point when developing 

and integrating technical plans. Rather than making this an ad hoc process, the framework’s 

complexity can be made less burdensome by making the steps explicit and understandable to 

all stakeholders and by allowing all stakeholders to have a chance to participate in the process. 

 The framework was designed for overcoming both institutional and technical issues. Initial 

emphasis is given to first resolving institutional issues. The best way to overcome institutional 

barriers is to create a systematic process that can be integrated into existing institutional 

processes. This framework provides a systematic process agencies and regions can follow. 

Guidance was given in the previous chapter on fitting a corridor management process into 

existing institutional structures. 

 The cyclical nature of the framework ensures that solutions developed meet the goals of the 

project and mitigate the problem; stakeholders can confirm that the investment in the corridor 

Adhering to a process ensures that all 

planning considerations are addressed and 

the potential for realizing the noted benefits 

of this framework are maximized. 
24 

is warranted. Also, lessons learned by monitoring and evaluating field conditions can be used 

to fine-tune corridor implementation plans and can be applied to additional corridor 

management efforts. 

 The framework is easily scalable based on the complexity of the corridor and required 

strategies. For smaller, less complex corridors, some steps may not need to be formally 

addressed. For example, a formal evaluation of operations strategies may not be necessary 

when there is only one feasible strategy. When all stakeholders agree a particular step does not 

need to be addressed, then stakeholders can move easily to the next step in the process. 

 Following a formal process with consensus by all affected stakeholders will help maximize 

the chances for securing funding for corridor implementation plans and procedures. 

Step 5: Corridor Scenarios and Operations Strategies 

Step 6: Evaluation and Selection of Strategies 

Step 7: Corridor Implementation Plan 

Decisionmaking 

Step 8: Design and Development 

Step 9: Deployment 

Step 10: Operations and Maintenance 

 Step 11: Continuous Improvement 

Continuous Improvement 

Step 1: Problem Definition 

Step 2: Institutional Considerations 

Step 3: Goals, Objectives, and Performance Measures 

Step 4: Corridor Concept of Operations 

Getting Started 

Implementation 

Figure 6. Chart. The coordinated freeway and arterial (CFA) operations framework. 

The remainder of this chapter discusses each of the 11 steps in the CFA operations framework in 

more detail. 

3.3 Step 1: Problem Identification 

The first step is to define the problem. A problem may be identified either through a formal 

performance monitoring process, which may be part of a regional planning process, or as the 
25 

result of an obvious operational problem such as traffic backing up onto a freeway due to an 

improperly timed arterial signal. 

The definition of the problem in the broadest sense begins at the regional planning and 

coordination stage. The regional planning process provides the institutional framework necessary 

to sustain the corridor planning process. At the regional level, problems are identified at a 

minimal level of detail as part of a planning and programming function. At the corridor level, 

discussed in this section, a more detailed level of problem identification is undertaken. 

The cause of a problem may be easy to identify at the regional level, such as the lack of traffic 

signal coordination between two adjacent jurisdictions. However, at the corridor level, problem 

definition may require more extensive analysis, especially when the congestion is widespread, to 

determine the true bottlenecks in a system experiencing extensive congestion. While it is easy to 

measure and identify symptoms of problems, the key is to identify the root causes of congestion 

in the corridor. 

There are four types of problems that are particularly amenable to coordinated corridor 

operations: 

 Incidents. 

 Work zones. 

 Special events. 

 Day-to-day/recurring operations. 

Incidents on freeways are the most readily addressed form of freeway congestion. Traditional 

actions like motorist service patrols that focus on quickly removing incidents, directly mitigate 

the effects of incidents. However, incidents may have significant secondary effects in major 

travel corridors, resulting in diversion to arterial streets which, if unprepared for the influx by 

unadjusted signal timing or other factors, can result in sprawling congestion on major 

thoroughfares. 

More significant corridor problems are also likely to result from major construction projects in 

work zones that require closed lanes, detours, or other modifications to roadway usage patterns. 

Special events can generate large traffic volumes, often at what would otherwise be off-peak 

times, creating congestion due to suddenly increased volume and, perhaps, unusual traffic 

patterns as large numbers of vehicles attempt to reach the same destination at the same time. The 

resulting corridor congestion can often cause significant delays to travelers who are not involved 

in the special event. The benefit of coordinated operations is that travelers will avoid the delays 

caused by special events. 

Day-to-day operations, while of little note, are perhaps the most sensitive to the iterative process 

of continued fine tuning to achieve optimum benefit. Issues related to these four specific problem 

types will be discussed in chapters 5. 

Initially, processes may not be in place to identify problems based on performance measurement 

systems (e.g., freeway and arterial performance measurement systems using detection and data 

archiving). Problems will be identified by more ad hoc systems, such as travelers registering 
26 

their concerns with public agencies; however, public agencies often discard problems brought to 

their notice as being outside their jurisdiction. Problems initially identified at the local level 

should also be provided to regional-level agencies for consideration. 

Finally, what one stakeholder sees as a problem may not be viewed as a problem by other 

stakeholders. For example, some local jurisdictions may object to accommodating freeway 

diversion traffic. However, lack of an initial consensus does not mean a solution cannot be 

reached. The goal of this phase of the process is to create an environment where mutual problem 

identification is possible as the first step towards resolution. The next critical step is developing 

the framework to work through the solutions. The institutional framework must provide a level 

playing field where all stakeholders—all parties who have an interest in a safe, efficient 

transportation corridor—explore issues and find win-win solutions. Coordination cannot take 

place when one or more participants are placed in what they perceive to be a situation where they 

will be obligated to contribute to a solution which is either inconsistent with their agencies’ goals 

or contradicts their agencies’ interests. 

3.4 Step 2: Institutional Considerations 

It is necessary to establish an institutional structure for the 

specific corridor being addressed in the coordinated operations 

framework. The institutional structure can be ad hoc or formal 

depending on the current state of coordination in the region and 

the complexity of the undertaking. Ad hoc arrangements tend to 

work best when long-term relationships between entities already exist or when the effort emerges 

from a specific project of limited duration. Formal agreements are used when either the 

complexity of the endeavor or the long-term nature of the undertaking require that the effort be 

implemented with formal agreements. There is no single best practice because of the unique 

nature of each region. The important point is to realize that an overarching structure is necessary 

to bridge the seams between the various agencies and even functions within agencies. 

Mechanisms for creating institutional structures may include personal relationships among 

leaders and staff members of key operating agencies and neighboring jurisdictions who 

recognize common problems and opportunities and agree to work together to improve corridor 

performance. These structures may evolve from or into a broad-based regional partnership 

among public and private sector interests across multiple jurisdictions. 

A formal organization can be legislatively established as a regional authority, or it can be 

established by a memorandum of understanding as a virtual organization. An example of a 

formal organization is metropolitan New York’s Transportation Operations Coordinating 

Committee (TRANSCOMSM), which was formed within the Port Authority of New York and 

New Jersey. TRANSCOM is a coalition of 16 transportation and public safety agencies in the 

New York, New Jersey, and Connecticut metropolitan region that provides a mechanism to 

facilitate collaboration and coordination among a variety of existing organizations, but does not 

replace them. Each existing organization has a specific, unique mission as well as a legal basis 

for existence and funding. The role of a formal organization is to provide a legitimate basis for 

collaboration and a mechanism to fund that collaboration. 

An overarching structure is 

necessary to bridge the seams 

between the various agencies and 

even functions within agencies. 
27 

Virtual organizations may be easier to establish than formal organizations and can rely on 

member organizations for corporate functions such as procurement, project management, and 

staffing. A virtual organization may look like a single entity to external observers, but behind the 

scenes, it will often be comprised of several different 

agencies and groups working together to produce and deliver 

specific products and services. An example of a successful 

virtual organization is AZTechTM. AZTech is a partnership of 

more than 75 public and private organizations led by the 

Maricopa County Department of Transportation (DOT) and the 

Arizona DOT whose goal is to use ITS to improve management of traffic and travel in the 

Phoenix metropolitan region. The partnership is able to share information through an integrated 

traffic management and information system consisting of cameras, traffic detectors, DMSs, 

CCTV, and personal communications devices designed to provide real-time travel information to 

travelers and traffic managers alike. 

To be effective, the collaboration and coordination must be linked to the regional transportation 

planning process. Often, what passes for collaboration is directed primarily or solely toward 

installing a project, solving a problem, or preparing for a special event. For corridor 

collaboration and coordination to work, it must be part of an ongoing, intentional, focused effort 

to improve system performance by identifying needs and opportunities and collaborating on 

strategies and solutions that lead to strategic investments. 

There is no one institutional structure that will meet the needs of all local circumstances. It is 

necessary to bring together the appropriate stakeholders and understand their individual needs 

and capabilities as well as their authority relative to the collaboration. While there is not one best 

structure, solutions can be found to virtually all limitations that any one agency may have in 

achieving collaboration and cooperation. 

3.4.1 Identify Corridor Stakeholders 

The success of a corridor initiative depends on participation by an appropriate set of 

stakeholders. Involving appropriate organizations at the early stages of the decisionmaking 

process facilitates their buy-in. 

Corridor stakeholders’ interest in improved operations will vary dramatically. In areas that have 

implemented substantial traffic management systems, the stakeholders may have an existing 

working relationship. As a result, these areas usually have operations management committees 

that provide a natural forum in which to discuss corridor traffic management. 

Other areas require more significant education and outreach efforts to assemble and motivate 

potential stakeholders. Educating the right people is important. Frequently education and 

outreach efforts target management levels in an organization where decisions are made to 

commit valuable personnel that support the corridor traffic management development effort. 

Without management support, it is difficult or impossible for those with a working knowledge of 

operations in the area to participate in corridor traffic management. 

It is often best to start with a core stakeholder group and then add participants to the core group 

over time. Too many stakeholders at the beginning can hinder the development process and 

The role of a formal organization is 

to provide a legitimate basis for 

collaboration and a mechanism to 

fund that collaboration. 
28 

discourage people with limited vested interest in corridor traffic management. Alternatively, it is 

also important to understand that it is difficult to get buy-in when stakeholders are brought into 

the process at the late stages. 

If it is decided to limit the number of participants to a core group initially, set a timeframe to add 

others. Table 4 provides a list of stakeholder organizations whose participation would be 

desirable and which may provide representatives to the group. 

It is also important to focus stakeholder participation appropriately. For example, both planners 

and system operators may participate in the process, but with substantially different 

contributions. System operators may be more interested in the operational concepts, functional 

requirements, and interface definitions, while the planners may have more substantial input into 

identifying transportation needs and services and project sequencing. Other individuals with 

specialized knowledge will be needed to assist in development of the list of agreements. As the 

“stakeholder roster” is developed, consider the various areas of expertise that are required and 

use your stakeholder resources selectively. Different stakeholders should be engaged in different 

parts of the process, consistent with their expertise and interests. 
29 

Table 4. Candidate stakeholder organizations or agencies. 

Organization or agency type Example organization or agency 

Transportation Agencies  State DOT. 

 Local agencies (city and county). 

 Department of public works. 

 Federal Highway Administration (FHWA). 

 Toll/turnpike authorities. 

 Bridge/tunnel authorities. 

Transit Agencies/Other Transit 

Providers 

 Local transit (city/county/regional). 

 Federal Transit Administration. 

 Paratransit providers (e.g., private providers, health/human 

services agencies). 

 Freight movers associations. 

 Intermodal facilities. 

Public Safety Agencies  Law enforcement. 

~ State police and/or highway patrol. 

~ County sheriff department. 

~ City/local police departments. 

 Fire departments. 

 Emergency medical services. 

 Hazardous materials teams. 

 Emergency response services. 

Other Agency Departments  Information technology (IT). 

 Planning. 

 Telecommunications. 

 Legal/contracts. 

Activity Centers  Event centers (e.g., sports, concerts, festivals, ski resorts, 

and casinos). 

 National Park Service. 

 Major employers. 

 Airport operators. 

 Intermodal transfer facilities. 

Travelers  Commuters. 

 Residents. 

 Bicyclists/pedestrians. 

 Transit riders. 

 Others. 

 Commercial vehicle operators. 

Private Sector  Traffic reporting services. 

 Local television and radio stations. 

 Travel demand management industry. 

 Telecommunications industry. 

 Private towing/recovery business. 

In addition to having appropriate stakeholders, it is necessary to understand their perspectives 

and issues. One group may focus on minimizing traffic disruptions caused by emergency 

workers, and overlook the need to protect the personal safety of the responders. However, by 

hearing all perspectives, problems can often be recast into win-win solutions. Better traffic 
30 

management becomes improved emergency worker safety and less exposure to potentially 

dangerous secondary traffic accidents caused by poor traffic management. 

The following is a categorical description of potential stakeholders and a representation of their 

perspectives: 

Users are the primary customers of the transportation system. Users include motorized 

transportation (e.g., motorcycles, automobiles, trucks, light and heavy rail, buses) and 

nonmotorized transportation, such as walking and bicycling. These customers are interested in 

safe, reliable, and predictable trips from their origin to their destination. They are generally not 

interested in the details of how the system operates, except when they encounter a system failure 

or disruption that influences the convenience or reliability of their trip. Additionally, users want 

real-time, accurate travel information to guide them on their trip. 

Decisionmakers (e.g., elected officials, agency heads, and so forth) develop legislation and 

policies addressing the funding, implementation, and management of the surface transportation 

network. They need to understand society’s needs and allocate available resources to best satisfy 

those needs. They also want to know the effects of their allocations. 

Responders, such as police, fire, and other emergency services, represent a “special user” 

category. They use the transportation network as part of their critical missions and often have 

decisionmaking and operational responsibilities for the network, particularly during traffic 

incidents, special events, and emergencies. 

Practitioners (e.g., agency managers, planners, designers, implementers, operators, and 

maintenance staff) are responsible for implementing the transportation projects and day-to-day 

management and operation. They are the providers who supply the many functions and services 

that require collaboration and coordination. They use the resources provided by the 

decisionmakers to provide travelers with transportation services, travel modes and options, and 

information that meet the users’ needs. These practitioners represent many different types of 

transportation agencies, including Federal, State, county, city, transit, and regional organizations. 

3.4.2 Corridor Champions 

The action steps necessary to establish a corridor traffic management program include not only 

identification of stakeholders but also identification of champions. 

A champion is an individual who believes in the program and is willing to put in the effort 

necessary to make it happen. Although a small project may not require high-level champions, the 

presence of a champion who commands significant resources (staff and funds) is most desirable. 

Champions are generally visible because they are proactive in the field of management and 

operations of transportation systems. A champion must be a stakeholder so that he or she has a 

vested interest in the outcome. But there is no rule saying that there can only be one champion; 

indeed, it is beneficial that more than one champion be identified from different agencies or 

stakeholder groups, including: 
31 

 Transportation agencies (traffic, transit, toll authorities, and others) that support the project 

because it meets their operational needs. 

 Public safety agencies that can bring aboard other public safety stakeholders. 

Champions need to have, in addition to an interest in the outcome, particular skills that will aid 

them in breaking down institutional barriers and establishing understanding and respect among 

the stakeholder group. These skills include: 

 Understanding of the subject. 

 Knowledge of local transportation systems and their operation. 

 Vision for collaboration, partnership, and coordination. 

 Ability to build consensus among individuals with varying priorities. 

 Executive-level access to resources. 

3.5 Step 3: Goals, Objectives, and Performance Measures 

Once the institutional structure is established, the stakeholders next identify the goals, 

objectives, and performance measures for the corridor. A goal is defined as a broad statement of 

the long-term outcomes of the program, such as: 

 Seamless traffic flow across jurisdictional boundaries. 

 Enhanced mobility through readily available information. 

 Safe and efficient movement of goods. 

Such goals enable all entities affected by coordinated operations to agree in simple layman’s 

terms as to the purpose of the coordinated operations. Moreover, the development of goals 

should be a bottom-up process with input coming from the stakeholders. The goal development 

process provides the opportunity to bring all the stakeholders to the table early in the overall 

CFA process, leading to a continuing dialog. Goal setting also helps establish priorities and 

ensures that the coordinated operations program is fully responsive to participants needs. 

Establishing goals sets the stage for the development of objectives and performance criteria. 

The next step is to determine specific objectives. Objectives detail how the goals will be 

achieved. Objectives are generally measurable because they are precise and quantifiable. An 

example of a measurable objective might be a reduction in incident-caused congestion by 25 

percent. 

Table 5 illustrates the relationship between goals and objectives. The establishment of goals and 

objectives allows stakeholders to reach consensus on what corridor management is attempting to 

accomplish before getting down to specific operations strategies. 
32 

Table 5. Example of goals and objectives for corridor operations. 

Goals Objectives1

Improve safety Reduce crash rate. 

Reduce accident severity. 

Reduce fatalities. 

Reduce recurrent congestion Improve traveltime. 

Improve average speed. 

Reduce vehicle hours of delay. 

Reduce nonrecurrent congestion Improve traveltime. 

Improve average speed. 

Reduce vehicle hours of delay during incidents. 

Improve incident response time. 

Improve travel reliability Reduce variation in daily traveltime. 

Reduce variation in daily average travel speeds. 

1

 Typically expressed as a quantitative change, such as percent reduction. 

Performance measures are needed to assess the success of efforts to collaborate and coordinate 

and to identify areas where improvement is needed. The first step related to performance 

improvement is finding a general consensus that performance measures are needed if corridor 

performance is to improve. Given this consensus, performance measures relevant to system-users 

must be developed and accepted as meaningful methods of assessing both the short-term and 

long-term operation of the corridor. Because corridor operations can be an evolving process that 

undergoes changes in institutional relationships, technology applications, and policy and 

procedures, the performance measures themselves may change over time. 

The performance measurement process is also an important part of the broader need for 

continuous improvement. Traffic operations are, by their very nature, a continually changing 

environment. As development takes place or traffic patterns change, system performance will 

also change, requiring a reevaluation of current operations. The performance measures provide 

the mechanism for quantifying the operation of the network and should also be used to evaluate 

the effectiveness of implemented traffic management strategies and to identify additional 

improvements. Vehicle-hours of delay would be an example of a congestion-related performance 

measure. 

There is not a single performance measure or a set of performance measures to meet all needs. It 

is therefore necessary for the stakeholder group to evaluate the strengths and weaknesses of 

alternative measures to meet the varying needs of each approach. The following are some 

characteristics of good performance measures: 

 Clearly understood. 

 Measurable. 

 Sensitive to modes (person-based). 

 Time-based (traveltime or speed, not volume-to-capacity ratio). 

 Link- or trip-based (to provide system monitoring). 

 Sensitive to time period (e.g., spreading of peak period, at least hourly, not daily data). 

 Not too difficult or costly to collect. 
33 

 Can be forecast into the future. 

 Sensitive to the impact of congestion mitigation strategies (on people and/or goods). 

Past definitions of congestion have fallen into two basic categories—those that focus on cause 

and those that focus on effect. Performance measurements clearly require a definition that 

addresses the effects, or symptoms, of congestion. Since traveltime or delays are the typical 

measures, congestion represents traveltime or delay in excess of that normally incurred under 

light or free-flow travel conditions. 

As stated, traveltime or difference in traveltime can be a basic measure. It can be used to 

compare door-to-door traveltimes by different modes. In addition, travel rate (e.g., minutes per 

mile) can be used to account for link-specific differences in the transportation network. 

Moving to a corridorwide operations approach makes it essential that the performance measures 

be consistent with the goals and objectives of the process in which they are being employed. It is 

also important to consider how the performance measures may be used including policy, 

planning, and operational situations. 

3.6 Step 4: Corridor Concept of Operations 

The corridor concept of operations is a formal document that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed in part to help communicate this view to 

the other stakeholders and to solicit their feedback. The corridor concept of operations provides a 

description of the current system, operating practices and policies, and existing capabilities. It 

lays out the program concept, explains how the corridor system is expected to work once it is in 

operation, and identifies the responsibilities of the various stakeholders for making this happen. 

The goals, objectives, and performance measures of a proposed operation are also documented. 

The process of developing a concept of operations for a corridor should involve all stakeholders 

and serve to reinforce the goals and objectives developed in step 3; to provide a definition of 

how functions are currently performed, thereby supporting resource planning; and to identify the 

interactions between organizations. Figure 7 schematically shows all of these issues and 

questions addressed in a concept of operations. 
34 

Figure 7. Chart. Questions addressed by a concept of operations document.(12) 

By definition, a concept of operations does not delve into technology or detailed requirements of 

the program. Rather, it addresses operations scenarios and objectives, information needs and 

overall functionality, details of where the program should be deployed, how users will interact 

with the various elements of the program, and performance expectations. The concept of 

operations must also address the “institutional” environment in which the corridor operations 

program is to be deployed, operated, and maintained. This environment includes all the potential 

stakeholders and their respective needs and perspectives, the relationships between the 

coordinated operations program and the policies/procedures of affected public agencies and 

private entities, and the necessary coordination (working relationships and agreements) between 

the stakeholders. 

The major goals of the concept of operations include:(12)

 Stakeholder identification and communication. The concept of operations document 

should facilitate discussion and assist participants in finding a middle ground associated with 

system design, development, and operation. 

 High-level system definition. Stakeholders must understand what it is the system is being 

designed to achieve. This definition will specify the major entities within the system, flows of 

information among both major internal entities and entities external to the operation, the highlevel capabilities of the system, and the primary daily activities of the system. 

 Foundation for detailed system descriptions. Detailed descriptions of the system begin with 

a high-level requirements document. Although the concept of operations is not a requirements 

document, a good concept of operations will provide enough information to develop a highlevel functional requirements document. 
35 

 Definition of major-user classes and user activities. Stakeholders will be made aware of the 

different types of users of the system and activities those users will perform. Everyone who 

uses the document will be able to understand who is performing what task and in what order. 

The most important aspect of this phase is that the questions of who, what, where, when, why, 

and how are answered. Of lesser importance is the exact format of the final concept of operations 

document, which should vary to some degree depending on the complexity of the system(s) and 

resources available to document the issues covered during this stage. While there is no standard 

outline for a concept of operations document, there are a number of core elements that a good 

concept of operations should cover that could be used as a high-level outline for the final 

document. These core elements include:(12)

 Establish scope—provides a summary of the entire concept of operations, including 

documentation of the goals, objectives, and performance measures for the corridor identified 

previously. 

 Identify reference resources—identifies resources critical to the development of the concept 

of operations. For corridor operations, this includes documenting the traffic management 

system designs, telecommunications, ITS and devices, related concept of operations 

documents, operations procedures, and existing traffic operations (delays, congestion levels, 

traffic volumes, and so forth) on the individual roadways in the corridor to be coordinated. If 

there is no description of current ITS and devices, then an ITS systems inventory is needed. 

Guidance on completing such an inventory is described in the appendix. 

 Develop a user-oriented operational description—describes how the concept of 

coordinated operations in the corridor will operate from a system-users perspective and how it 

will impact the way users will view the corridor. This portion describes the vision of 

coordinated operations in the corridor, including how the envisioned system satisfies the goals 

and objectives for the corridor. 

 Establish or identify operational needs—identifies the operational, institutional, policy, 

procedural, or technology gaps of agencies that need to be filled to meet the operational 

system described in the previous step. The needs or requirements to fulfill the operational 

system may overlap agency boundaries within the corridor and, as such, a clear description 

and understanding is needed of who has responsibility for operating and maintaining the 

systems or infrastructures. 

 Provide a system overview—provides an overview of how different system parts relate to 

each other and who is responsible for each part. This section takes the operational description 

given above and shows the interfaces between the different components of the system. 

 Describe the operational and support environment—describes the environment, or 

“world,” in which the corridor operations plans will be carried out. The facilities, equipment, 

hardware, software, personnel, operations procedures, and additional support that together 

make the current corridor operations possible are documented here. 

 Develop operations scenarios—develops high-level operations scenarios that are likely to 

happen in the corridor. For example, if the corridor is focusing on incident management, then 

a number of scenarios could be developed based on the location, severity, and duration of the 

incident (e.g., one scenario could be a fatal crash on Interstate 90 during the p.m. peak). 

Developing such scenarios allows for adequate operations plans and procedures to be prepared 

at a later stage for a number of common scenarios. 
36 

Chapter 4 presents examples of how these core elements can be incorporated into a corridor 

concept of operations for corridors that are dealing with problems related to incident 

management, work zones, special event management, and day-to-day operations. 

3.7 Step 5: Corridor Scenarios and Operations Strategies 

The corridor concept of operations can be thought of as “a vision of what we want to do,” while 

step 5 can be thought of as “a vision of how we want to do it.” This step takes the corridor 

concept of operations to a more comprehensive level by developing more detailed corridor 

scenarios and then identifying specific operations strategies to address these scenarios. 

The first part of this step takes the description of operations scenarios developed in the corridor 

concept of operations to a more detailed level. It is important to develop a range of operations 

scenarios to an adequate level of detail that can be used to determine which operations strategies 

are needed. These detailed scenarios need to represent the range of conditions that could occur in 

the corridor. 

Table 6 displays examples of how the high-level scenarios developed in step 4 can be taken to a 

more detailed level in step 5. The detailed corridor scenarios should be developed with the 

assistance of, or at the least the concurrence of, the stakeholders. Key considerations in the 

development of scenarios include: 

 Event—the nature of the event that is triggering the need for action (e.g., crash, sports event, 

work zone). 

 Location—the location of the event. An incident on a minor arterial will require different 

operations strategies than an incident on a major freeway. 

 Time—the time of day and week that the event occurs. An incident during the p.m. peak will 

likely require different operations strategies than a midday incident. 

 Duration—how long the event occurs. A work zone that closes lanes for 1 week will require 

different operations strategies than one that has a 1-year duration. 

 Severity/Impact—how severe the event is and what impact it has on its surroundings. The 

severity/impact is a function of the four previous considerations. For example, a minor rearend crash on an arterial during off-peak conditions will have far less impact than a fatal crash 

on a freeway during the p.m. peak. 
37 

Table 6. Developing detailed corridor operations scenarios. 

Opportunity for 

Coordination 

High-Level Scenario 

(From Concept of 

Operations) 

Detailed Scenarios 

Incident 

Management 

Fatal crash on I–90 

freeway during p.m. peak 

• Fatal crash on I–90 between Exits 5 and 10 in 

westbound direction. 

• Fatal crash on I–90 between Exits 5 and 10 in 

eastbound direction. 

• Fatal crash on I–90 between Exits 10 and 15 in 

westbound direction. 

• Fatal crash on I–90 between Exits 10 and 15 in 

eastbound direction. 

Work Zone 

Management 

I–90 freeway lanes closed 

during construction 

• I–90 left two lanes closed during p.m. peak 

hours. 

• I–90 left two lanes closed during off-peak 

hours. 

• I–90 right lane closed during p.m. peak hours. 

• I–90 right lane closed during off-peak hours. 

Special Event 

Management 

Sports event creates 

queues on freeway 

blocking exits to local 

businesses/neighborhoods

• Freeway queue blocks Exits 5 through 7 for 30 

minutes. 

• Freeway queue blocks Exits 5 through 7 for 

more than 2 hours. 

• Freeway queue blocks Exits 5 through 10 for 

30 minutes. 

• Freeway queue blocks Exits 5 through 10 for 

more than 2 hours. 

Day-to-Day 

Operations 

Freeway bottleneck 

causes vehicle diversions 

onto parallel arterial 

during p.m. peak 

• Minor diversion traffic (< 500 vehicles per hour 

(veh/h)) on arterial between 1st and 5th Streets. 

• Major diversion traffic (> 500 veh/h) on arterial 

between 1st and 5th Streets. 

• Minor diversion traffic (< 500 veh/h) on arterial 

between 5th and 10th Streets. 

• Major diversion traffic on arterial (> 500 veh/h) 

between 5th and 10th Streets. 

Once the more detailed corridor scenarios have been developed, then specific operations 

strategies can be identified that will help mitigate the impacts of the scenarios. Having available 

the range of possible scenarios will be helpful in identifying potential operations strategies. 

During this step, strategy identification will be at a conceptual level. Strategies should be 

identified based on input from the corridor stakeholders. Desirably, the identified strategies are 

those that will: 

 Help solve the problems defined in the detailed corridor scenarios.

 Be approved by corridor stakeholders.

 Meet the goals and objectives for the corridor.

 Be consistent with the operational description and overview provided in the corridor concept 

of operations.
38 

 Make the most of the existing systems (hardware, software, telecommunications, and so 

forth.) and procedures on the corridor to help minimize additional requirements.

In the next step, the identified strategies will be evaluated more rigorously to select the best 

possible strategies for the corridor. The types of strategies that are appropriate for coordinated 

operations on a corridor can be grouped into three categories: 

 Traveler information. 

 Traffic management and control. 

 Shared information and resources. 

The difference in perspective for the strategies above is they are viewed from a corridorwide 

perspective. The following discussion in this section provides an overview of the range of 

strategies available for improving coordinated operations on a corridor. 

3.7.1 Traveler Information 

Most regions provide traveler information by one or more traveler information media, but often 

the information is not coordinated in a corridorwide perspective. Traveler information that is 

focused solely on a freeway or arterial streets can have either positive or negative effects on the 

entire corridor. For example, a DMS that suggests using alternate routes due to a freeway 

incident can potentially have a negative impact on a parallel arterial if appropriate traffic 

management and control plans do not support potential motorist rerouting in response to the 

information. Thus, it is easy to see the need for a corridorwide view of traveler information. 

 

In this day of advanced communications technologies, there are a multiple ways to disseminate 

information among travelers, including: 

 

 Web pages. 

 Pagers/personal data assistants (PDA). 

 Telephones/511. 

 DMSs (fixed and portable). 

 Commercial radio broadcast. 

 Commercial television broadcasts. 

 HAR. 

 Citizens’ band (CB) radios. 

 Dynamic route guidance signs (sometimes referred to as trailblazer signs). 

 Kiosks. 
39 

The list of ways to communicate traveler information 

reflects both formal and informal sources of information. 

Informal sources include the use of CB radios by truckers. 

Formal sources include DMSs (figure 8) and private sector 

traffic information providers that broadcast radio traffic 

services. By expanding the quality and extent of 

information provided, travelers can implement their own 

rerouting plans or defer their trips. Either way, the result is 

improved system performance. 

 

A coordinated view of traveler information has two 

benefits. First, it does not provoke a negative impact on the system by focusing information on 

only one part of the system (i.e., the freeway or the arterial). Second, it focuses on traveler 

information as a system approach to maximizing corridor performance. During peak traffic 

times, traveler information may cause motorists to delay or even cancel trips, reducing demand. 

During off-peak times, traveler information may make the system more efficient by encouraging 

the use of less active portions of the transportation system, which has the capability of absorbing 

excess demand from the portion of the system experiencing congestion. 

Critical aspects of information include the time it reaches travelers (pretrip, en route), the type of 

information (condition, guidance), the extent of the information (link-based, corridor-based), and 

the method of dissemination (Web site, radio, HAR, DMSs, trailblazer signs). The more system 

oriented the information, the better decisions travelers can make. 

In addition, the further in advance information can be provided, the more likely a desirable 

outcome will result. If travelers receive information before leaving home or work, alternative 

routes are significantly more often used than when travelers are already caught in traffic. A 

coordinated traveler information strategy would ideally use a single metropolitan area Web site 

and contain both freeway and arterial travel information. Estimated traveltimes could be 

provided for alternative routes, along with information on events along all routes. During the 

middle of the day, information on work zone activities could be provided on a corridor traffic 

map indicating the nature and location of work zones. 

Improving the nature of information provided is also important. Traditionally, because of the 

lack of coordination between operating agencies, traveler information was largely advisory and 

only related to the agency owning the DMS. By developing agreed upon operations plans, more 

specific guidance information can also be provided to help travelers take specific actions, such as 

taking a diversion route around a freeway incident. 

One particular issue to decide is whether to provide route guidance as part of the traveler 

information system. Dynamic route guidance around particular incidents, work zones, or other 

causes of congestion is particularly beneficial to motorists when taking a corridorwide 

perspective. However, providing route guidance is difficult for a number of reasons. Among the 

issues to consider are the availability of real-time information on both the original route and 

alternate routes, the amount of capacity available on alternate routes, the infrastructure needed to 

provide dynamic route guidance (DMSs, trailblazer signs, static signs, and so on), the potential 

response of motorists to the guidance (e.g., a large percentage of motorists unfamiliar with the 

Figure 8. Photo. Sample DMS 

message. 
40 

surroundings may not be willing to change routes), and the impacts on neighborhoods and local 

businesses. Once a decision is made to provide dynamic route guidance, choosing specific 

alternate routes can also be difficult. A survey of public agencies revealed the top 10 criteria 

used when selecting alternate routes: (13)

 Proximity of alternate route to affected roadway. 

 Ease of access to/from alternate route. 

 Safety of motorists on alternate route.

 Height, weight, width, and turning restrictions on alternate route. 

 Number of travel lanes on or capacity of alternate route. 

 Congestion induced on alternate route. 

 Traffic conditions on alternate route. 

 Number of signalized intersections, stop signs, and unprotected left turns on alternate route. 

 Traveltime on alternate route. 

 Pavement conditions on alternate route. 

A coordinated traveler information strategy includes shared use of information systems. For 

example, a freeway DMS that typically provides traffic information on the freeway could also 

provide information on congestion on nearby streets caused by incidents or special events. Realworld examples are evident in the Phoenix, AZ, and Washington, DC, metropolitan areas where 

DMSs located on arterials adjacent to freeways provide congestion information on the freeways, 

giving motorists the opportunity to avoid the congestion before entering the freeway. Without a 

broad view of traffic management, the DMS does not achieve its maximum potential as a 

corridorwide traveler information system. 

Overall, achieving a corridor approach to traveler information dissemination requires a broader 

look at the available systems and the interconnections necessary to implement the corridor 

information program. Issues that may need to be addressed include center-to-center 

communication and shared control of traveler information systems such as Web sites and DMSs. 

A coordinated traveler information program may require the development of cooperative 

agreements. A cooperative agreement is a formal statement of recognition and commitment by 

the participating agencies regarding their roles and responsibilities in the operations of the 

corridor. Such details are finalized in step 8 of the CFA operations framework. 

3.7.2 Traffic Management and Control 

Traffic management and control strategies can be divided into three categories: 

 

 Coordinated traffic signal timings. 

 Lane-use adjustments. 

 Access control. 

3.7.2.1 Coordinated Traffic Signal Timings 

Traffic signals are operated by the responsible local jurisdiction or its designee. However, the 

boundaries of these operating agencies often do not constitute logical break points in a traveler’s 

journey; therefore, one simple means of improving corridor operations is to develop timing plans 

jointly in a way that reflects the users’ systemwide view of travel. 
41 

The simplest opportunity to coordinate operations is expanding traffic signal timing issues 

beyond individual agency boundaries. This can be accomplished in many different ways 

depending on the specific situation. An example of this would be in an area where a city agency 

controls all the traffic signals approaching an interchange, and the State operates the two traffic 

signals at the interchange. The State traffic signals could be added to the city system for 

coordination purposes by extending the traffic signal interconnect if the agencies have 

compatible equipment. Such an arrangement does not require one agency to give up control; it is 

only necessary to allow another agency to provide the necessary coordination functionality. The 

technical issues involved in such coordination include establishing the necessary 

communications infrastructure and forming agreements on the coordination timing parameters. 

Institutional issues could include development of formal agreements, if necessary, and 

procedures to address how the two agencies resolve any operational and maintenance problems 

that may arise. 

The means for implementing cross-jurisdictional traffic control can vary from a simple 

agreement to operate a common time reference, cycle length, and offset, to more sophisticated 

integrated systems. The more complicated the timing strategies, the more sophisticated the traffic 

control system needs to be, but simple solutions are also possible in many cases. For example, 

peak-hour coordination can be achieved easily by using pre-arranged timing plans with a 

common reference time. Preplanned incident response plans can be implemented in a number of 

ways, including via simple telephone calls to the collaborating agency. Another option would be 

to grant limited control access to the collaborating agency, especially when one agency has 24-

hour/7-day-a-week operations, and the other does not. 

 

Another boundary between subsystems occurs between freeway control systems and arterial 

control systems. These boundaries can cause operational problems because of uncoordinated 

day-to-day operations or as a result of nonrecurring congestion affecting normal traffic. As noted 

previously, any effort to alleviate congestion on one system without taking into account the 

impact of diverted traffic on other systems in the corridor can have a significant negative impact. 

In systems without coordination, it is possible to have a situation where traffic signal control on 

an arterial favors arterial coordination and ignores traffic exiting the freeway. As a result, there is 

no information on the impacts of the arterial signal timing on freeway operations. However, a 

more integrated system would provide feedback to the arterial control system about excessive 

queues spilling back on the freeway and provide the option to adjust signal timing accordingly to 

alleviate the backup. 

Another example of subsystem interaction is ramp metering. Ramp metering considered in 

isolation from adjacent signal timing can adversely affect both ramp metering and the traffic 

signal operations. If the traffic signal discharges traffic onto the ramp in large groups because of 

long cycle lengths, the meter may have to go to less restrictive metering to discharge the queue, 

reducing the effectiveness of the ramp metering (figure 9). If restrictive ramp metering backs up 

traffic onto the arterial, arterial operations may suffer, negatively impacting the overall system 

performance. 

 

The types of strategies used to coordinate signals effectively within a corridor include local, 

areawide, diversion, and congestion strategies. 
42 

Local Coordinated Strategy. This mode of operation 

implies the need for a close and responsive interaction 

between the ramp meter controller and the traffic signal 

controller. The ramp-metering rate should be adjusted based 

on the current traffic signal timing at the interchange. Signal 

timing may also be modified based on current ramp metering 

rates, whichever is more critical at that time. 

 

Areawide Integrated Strategy. This is a traffic-responsive 

strategy that sets metering rates based on corridor flow rather 

than local conditions at the interchanges. The areawide 

strategy also requires frequent adjustments in traffic signal 

timing plans as well as ramp metering rates to react to shortterm stochastic changes in traffic flow. 

 

Diversion Strategy. The diversion strategy is designed to 

handle incidents by assigning special timing plans to both 

arterial traffic signals and ramp meters at locations affected 

by the diversion strategy. 

Congestion Strategy. When traffic demand exceeds capacity 

in a portion of the corridor, the objective of the traffic control 

strategy will be to manage the spread of congestion rather than the demand. The goal is to 

minimize the adverse effect that the congestion has on overall system performance by controlling 

the location of queues. 

3.7.2.2 Lane-Use Adjustments 

Lane use is often set up based on peak-hour traffic and is prescribed by static signing. This 

approach generally meets routine needs, but is not responsive to changing traffic conditions. 

Dynamic lane assignment signs may be an appropriate treatment for locations with variable 

traffic as well as for areas that suffer congestion due to traffic incidents or special events. 

Figure 10 illustrates a dynamic lane assignment location on a freeway frontage road. The 

location could also be a more typical freeway ramp to an arterial where the normal operation is a 

single lane turning right. Under a certain event (e.g., incident, work zone, or special event), the 

strategy might include converting the right turn to a double right turn. The strategy would be 

effective, however, only if the receiving roadway network was timed to accept the extra traffic 

caused by the event. This type of strategy could also be used during different times of day to 

reflect different traffic patterns. 

Figure 9. Photo. 

Uncoordinated arterial 

signals can cause reduced 

effectiveness of ramp 

metering on freeways. 
43 

These changes might be routinely implemented based 

on time of day, so that hourly variations in traffic can 

be addressed. With the appropriate control systems, 

dynamic lane assignment could also be used for 

nonrecurring events to improve corridor operations. 

 

Lane-use control can also be provided on freeways to 

improve incident management, traffic flow, or to 

improve merging capacity. These techniques can be 

used to expedite flow onto or off of freeways as part 

of a CFA management strategy. 

Effective lane use should represent current traffic 

demands, especially when it is at or near capacity. 

Lane-use control is not as effective in dealing with 

average traffic demand in a corridor. 

3.7.2.3 Access Control 

Access control can include turning restrictions, ramp metering, or even ramp closure. While 

ramp metering is an example of limited access control, as are turn restrictions, a variety of 

measures can be taken to restrict access. Gates on either entrance or exit ramps to or from 

freeways are a means of controlling access. This can be done using traffic control devices that 

are deployed on a temporary or permanent basis. 

 

CFA management deals with access control to the corridor level. From this perspective, the most 

important goal is the effective use of available traffic capacity. The success of any access control 

strategy within a corridor, however, will depend on the scenario being addressed. 

3.7.3 Shared Information and Resources 

Sharing information and resources across and within agency boundaries takes the concept of a 

shared, coordinated system to a more comprehensive level of integrated corridor operations. 

Perhaps the simplest examples of sharing are those that involve information. Information can be 

shared in a variety of ways from simple telephone exchanges to electronic pager and e-mail 

notifications. The information to be shared can also vary from the awareness of an incident to 

notification of the implementation of a specific operations plan. 

 

An example of information sharing would be an incident report from a freeway traffic 

management system that is shared by way of an e-mail to the city traffic signal control center. 

The shared information could provide insight into such potential solutions as traffic diversion to 

parallel routes. 

Sharing surveillance cameras among agencies is an example of a shared resource that could 

allow another agency to gather information. For example, a freeway surveillance camera at an 

interchange could provide the arterial management agency with information on street conditions 

without the need to invest in their own camera. 

Figure 10. Photo. Dynamic lane 

assignment on an arterial. 
44 

Other resources that could potentially be shared 

include various incident response equipment such 

as service patrols, wreckers, and portable DMSs. 

Application of shared resources of information 

would be most valuable, for example, in the case 

of a special event where one agency may not have 

sufficient assets to manage the situation 

effectively. 

 

Shared operations could allow an agency with a 

24-hour/7-day-a-week operation (figure 11) to 

take preplanned actions using another agency’s 

equipment when the owning jurisdiction is not 

staffed. Limited operational control might even be 

given to a nontraffic agency such as the police 

during hours where the traffic agency does not staff their traffic operations center. The goal is to 

maximize the public investment by sharing resources to provide the best operation of the system. 

3.8 Step 6: Evaluation and Selection of Strategies 

Once a number of potential operations strategies have been identified, an evaluation of the 

strategies ensures that the most appropriate strategies are selected. The evaluation process and 

criteria should reflect the goals and objectives that were established earlier and can vary from 

simple to complex. Strategies that require multiple stakeholders are more complex because of 

competition for resources. As a result, the details of a particular strategy may have profound 

effects on how a project is ultimately viewed by stakeholders as a group. It is therefore necessary 

to have a flexible approach to selecting potential strategies and understanding that all parties 

must be willing to support the strategies to be implemented. 

The evaluation required for larger projects may include an assessment of the costs and the 

benefits of the project. The structure and formality of the evaluation process used to assess the 

costs and benefits of the alternatives will depend on the complexity and coordination needs of 

each agency. 

In addition to complexity, the appropriate evaluation process should take into account several 

other considerations, including existing planning processes in the region. The assessment needs 

to reflect the evaluation and selection process already used by agencies for other types of 

program development. Some strategies, like coordinating signals across jurisdictional 

boundaries, may be simple depending on existing equipment and staff resources, and 

implementation may be accomplished in-house using existing resources to develop and 

ultimately implement the new plans and procedures. More extensive control strategies can 

require more comprehensive analysis to justify the expenditures required for design, 

implementation, operations, and maintenance. 

 

Strategy evaluation may incur a high cost relative to the expense of actual CFA plan 

implementation and maintenance. For example, large or complex projects may use a traffic 

microsimulation model, which can require considerable time and resources to use correctly. 

Figure 11. Photo. A freeway TMC 

collects and shares information from 

many sources. 
45 

Costs of performing a traffic analysis should be considered when estimating the overall costs of a 

CFA plan for a corridor. 

There are various ways to prioritize and select alternative strategies, including many traditional 

economic analysis tools like benefit/cost ratios. Categories of funding are often created to 

address specific problems such as safety or capacity. Others use rankings based on weighted 

evaluation criteria. The criteria should represent the goals and objectives of the local area, with 

relative importance being reflected in the weights. Criteria could, for example, include improved 

system performance and improved air quality. 

The last element of the evaluation is matching the expected outcomes with the corridor goals and 

objectives. The evaluation results should be expressed in the same terms as the performance 

measures developed earlier in the process. These performance measures can be used to determine 

whether the proposed strategies meet the corridor goals and objectives. While a certain strategy 

may be ranked the highest in terms of meeting the specified objectives for the corridor, the 

evaluation should also consider: 

 How the strategies can be changed to meet operational objectives more efficiently. 

 Whether the strategies are realistic and will be accepted by all corridor stakeholders. 

 Additional resources and tools that are needed to fully meet the corridor objectives. 

Overall, the evaluation and selection process can be simple or complex, but it should at least 

apply an appropriate traffic analysis tool, apply valid analysis methodologies, be understood and 

approved by stakeholders, and ensure the selection of realistic, effective, and efficient strategies 

that meet the goals and objectives for the corridor. Detailed information on selecting the 

appropriate traffic analysis tools and applying the tool correctly can be found at the FHWA 

Traffic Analysis Tools Web site: http://ops.fhwa.dot.gov/trafficanalysistools/index.htm. 

3.9 Step 7: Corridor Implementation Plan 

Upon selection of the operations strategies for the corridor, the next step is development of the 

corridor implementation plan. The purpose of the corridor implementation plan is to provide 

enough detail so that agencies can proceed to developing operations plans and procedures and 

designing systems and technologies that support the plans and procedures. The corridor 

implementation plan is a document with two essential functions: 1) it summarizes all work 

completed up to this point to serve as a reference for all interested parties if strategies are not 

designed and implemented immediately, and 2) it provides a roadmap for recommended funding 

and implementation of the individual projects needed to support the corridor operations 

strategies. To support this second function, the corridor implementation plan should define 

expectations over time (what is to be accomplished), processes (how it will be accomplished), 

and resources (investments in time, money, staff, and equipment). 

 

Corridor operations rely on activities and relationships that can occur only if individuals and 

organizations commit appropriate funding, staff, and possibly equipment. Implicit in this 

statement is the allocation, and possible sharing, of resources that enables a region’s operators, 

service providers, and other stakeholders to improve system performance. Operations must be 

viewed as a resource priority by participating organizations. The corridor implementation plan 
46 

should address the availability of resources for putting a concept of operations into practice, 

implementing agreed upon strategies, and sustaining operations on an ongoing basis. 

Most funding for operations will come from individual agency budgets. This may involve 

agreements to share key resources (equipment and personnel) across jurisdictional boundaries or 

among operators or service providers; agreements on acquisition and procurement that ensure 

interoperability and standard protocols for communications and data exchange; or potentially, the 

identification of capital investments in operations-related infrastructure (networks, operations 

centers, sensors) to be deployed on a regional basis or in conjunction with other capital 

improvement projects. Funding for such projects requires that operating agencies and service 

providers have a role in the region’s capital planning process. The corridor implementation plan 

is the vehicle for securing specific project-related funding to implement the corridor operations 

strategies. 

 

Another value of the corridor implementation plan is that it provides a record of the process. As 

staffs change, the plan provides the necessary details that allow others to pick up the plan and not 

have to revisit the steps leading up to the plan. This does not mean that the plan needs to be 

static. Plans will always need to be updated based on changing circumstances, but even so 

having a corridor implementation plan will provide the background on how strategies were 

developed and whether or not they need to be updated. 

 

Overall, the corridor implementation plan is a document that provides complete details on the 

first six steps of the coordinated operations framework. The exact format of the corridor 

implementation plan is different depending on the size and complexity of the coordination 

required; however, an example of the elements that could be included in the corridor 

implementation plan document includes: 

 

 Goals and objectives for corridor. 

 Summary of corridor concept of operations. 

 Summary of corridor scenarios and selected operations strategies. 

 Phasing of efforts or projects necessary to implement operations strategies. 

 Staffing/personnel needs. 

 Capital, operating, and maintenance costs. 

 Potential funding sources. 

 Schedule for corridor implementation. 

A corridor implementation plan becomes a real benefit when funding sources are not 

immediately secured and thus design and implementation will be delayed. In these cases, having 

a record of the process and results is imperative, as well as providing a roadmap for project 

funding and implementation. If adequate funds are already secured and agencies are ready to go 

directly into the design and development stage, a formal corridor implementation plan may not 

be necessary. 

3.10 Step 8: Design and Development 

The design and development phase translates each of the various projects included in the corridor 

implementation plan into workable project plans. This phase consists of two primary 
47 

components: developing operations plans and procedures to accomplish the selected operations 

strategies and designing the systems and technologies (hardware, software, telecommunications, 

ITS and traffic control field devices, etc.) needed to support the plans and procedures. Because 

this document is not intended to serve as a detailed technical manual on systems design, details 

such as how to design various ITS technologies and systems is not discussed here. Rather, this 

section will focus on the development of plans and procedures needed to support the operations 

strategies identified earlier in the process. 

A plan defines what will be done, while a procedure defines how it will be done. The plan should 

accomplish the operations strategies selected earlier. However, the operations strategies are fairly 

broad (i.e., arterial signal timing to support freeway traffic diversion); thus, more detailed plans 

must be developed to define precisely how the strategy will be implemented. In addition, 

multiple plans will be needed to respond adequately to the range of scenarios that could occur. 

For the example of arterial signal timing to support freeway diversion, multiple signal timing 

plans will be needed depending on the scenario that occurs. Three different signal timing plans 

could be created to account for light diversion, moderate diversion, and heavy diversion 

scenarios. Developing each of these plans includes defining what traffic signals will be affected 

and what changes will be needed (e.g., the signal offsets, cycle lengths, and green splits could all 

be changed). It is imperative that the plans be developed in advance so agencies can quickly 

implement the plans in real time based on the scenarios that occur. 

Operations plans are needed for each operations strategy selected; therefore, numerous plans 

could be created for DMS messaging, signal timing, ramp meter timing, dynamic lane 

assignment, access management, traveler information dissemination, sharing agency information 

(e.g., State TMC operator shares freeway conditions with city engineer), and sharing agency 

resources (i.e., State TMC operator controls city traffic signals after regular office hours). As a 

result, many operations plans will be created for the corridor. One way to organize the operations 

plans is to combine them into logical groupings based on each scenario. Figure 12 shows an 

example of how operations plans can be grouped together based on the operations scenarios and 

strategies. 

Figure 13 shows the individual scenarios developed previously in step 5 of the coordinated 

operations framework further subdivided into subscenarios (i.e., scenario 1 divided into scenarios 

1A, 1B, 1C, etc.). Subdividing the scenarios in this manner may be necessary depending on the 

level of detail required. In the figure, the scenarios were subdivided using an activation matrix, 

which in this case is a two-dimensional grid of the number of lanes blocked and time of day of 

the incident. Various criteria can be considered for the activation matrix based on the event, 

location, duration, time, and severity/impact of the event as discussed in section 3.7. 

After developing the operations plans, procedures are needed to define how the plan will be 

implemented. The procedures define the roles and responsibilities for the plan, or who will do 

what and when should it be done. Specific steps need to be defined for each plan, including when 

it should be activated, sequence of steps needed to complete the plan, who is responsible for each 

step, and when the plan should be deactivated. Using an activation matrix such as that shown in 

figure 12 is one way to detail when a plan should be activated. Figure 13 shows an example of 

how procedures can be developed and documented based on the various operations plans. 
48 

Recognition of existing procedures needs to be taken into account when developing these new 

procedures and overlap is discovered between what is currently done and what is proposed. For 

the example in figure 13, the normal incident management procedures by the State TMC 

operator were incorporated into the corridor operations procedure. 
49 

Figure 12. Chart. Example of development of corridor operations plans. 

Scenario 3

Scenario 2 

Incident on I–5 Northbound 

between mileposts 50 and 60 

Scenario 1 

Activation Matrix

Off Peak 

AM, PM 

Peaks 

2 Lanes 

Closed 

1 Lane 

Closed 

Full 

Closure

Scenario 

1A 

Scenario 

1D 

Scenario

1E 

Scenario

1F

Scenario

1B 

Scenario

1C

Criteria 

Plan DMS-1: Freeway DMS messages 

Plan DMS-2: Freeway and arterial DMS 

messages 

Plan DMS-3: DMS active route guidance 

DMS Messaging 

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer 

Plan SI-3: TMC operator controls city 

signals 

Plan ST-1: Standard timing plan 

Plan ST-2: Light diversion plan 

Plan ST-3: Heavy diversion plan 

Signal Timing 

Plan LA-1: No changes 

Plan LA-2: Convert turn lane into through 

lane. 

Plan LA-3: Temporarily close key onramps 

Shared Information Lane Assignments 

Corridor Operations Strategies 

Operations Plans

Plans 

1D 1F 1E 

DMS-1 

ST-1 

SI-1 

LA-1 

Scenario 1B 1A 1C 

DMS-2 

ST-2 

SI-2 

LA-1 

DMS-3 

ST-3 

SI-3 

LA-1 

DMS-2 

ST-2 

SI-2 

LA-1 

DMS-3 

ST-3 

SI-2 

LA-2 

DMS-3 

ST-3 

SI-3 

LA-3 
50 

Figure 13. Chart. Example of development of corridor operations procedures. 

In addition to defining responsibilities for the operations plans, responsibilities should also be 

defined for those agencies and departments that own physical systems and equipment, whether or 

not equipment will be shared (and who has control override), and who is responsible for 

maintenance. Figure 14 shows an example from Portland, OR, where responsibilities were 

agreed on and explicitly stated in a corridor operations plan. 

Operations Plans

Plans 

1D 1F 1E 

DMS-1 

ST-1 

SI-1 

LA-1 

Scenario 1B 1A 1C 

DMS-2 

ST-2 

SI-2 

LA-1 

DMS-3 

ST-3 

SI-3 

LA-1 

DMS-2 

ST-2 

SI-2 

LA-1 

DMS-3 

ST-3 

SI-2 

LA-2 

DMS-3 

ST-3 

SI-3 

LA-3 

Operations Procedures

1B 1. Verify field conditions match scenario. 

2. Begin typical incident management plans. 

3. Phone city engineer of conditions (Plan SI-2).

4. Implement DMS messages (Plan DMS-2). 

5. Implement signal timing (Plan ST-2). 

6. Monitor field conditions and check if 

different scenario is activated. 

7. Deactivate plans when warranted. 

Scenario Action Steps Responsibility 

1. State TMC operator. 

2. State TMC operator. 

3. State TMC operator. 

4. State TMC operator. 

5. City signal engineer. 

6. State TMC operator and 

city signal engineer. 

7. State TMC operator and 

city signal engineer. 
51 

N/A = Not applicable. 

P = Primary control with override capability. 

S = Secondary control that may be overridden by primary agency. 

ODOT = Oregon Department of Transportation. 

VMS = Variable Message Sign. 

CMS = Changeable Message Sign.

Figure 14. Chart. Example of identifying field equipment responsibilities.(14)

In defining relationships for sharing equipment, it is important to define the boundaries of 

control before implementing the plans. For example, if one agency has agreed to allow another 

agency to take control of a CCTV system under specific circumstances, those circumstances 

must be laid out in the greatest detail possible, delineating both the triggers for handoff as well as 

the circumstances for returning control to the principle authority. The formality of the definition 

of the organizational relationships will depend on the complexity of the operations plans and the 

legal requirements of each organization involved. 

Cooperative agreements between agencies (public or private) may be needed to support the plans 

and procedures developed at this stage. Cooperative agreements can take many forms, such as 

resolutions, memoranda of understanding (MOU), intergovernmental agreements, or 

some combination of these. The cooperative agreements should be agreed upon and signed 

before the actual implementation of the systems, plans, and procedures. More detail on this 

subject, including guidance and lessons learned on developing cooperative agreements for 

corridor management, is available in NCHRP Synthesis of Highway Practice 337: Cooperative 

Agreements for Corridor Management.

(15)
52 

3.11 Step 9: Deployment 

The deployment stage consists of the implementation of plans and procedures and the installation 

of ITS and traffic control devices, including telecommunications hardware and software. Getting 

the public involved and aware of the project throughout the entire planning and design process is 

essential. Prior to starting the system, a targeted public outreach campaign should be 

implemented where motorists’ travel through the corridor will be altered by the corridor 

implementation plans and procedures. Negative media coverage and/or public complaints to 

local leaders and elected officials have the potential to entirely shut down a corridor operations 

project, so it is clear that the public, media, agency management, and even elected officials 

should be educated on how the systems work, how it affects motorists travel, and the benefits of 

the system to corridor residents and businesses. 

 

The public outreach should be targeted to motorists who drive through the corridor on a regular 

basis, who live or have a business near the corridor, and who may be effected by the corridor 

operations plans. Distributing marketing materials, releasing press statements, granting 

interviews to television stations and other media, and attending neighborhood meetings are all 

viable methods to help the public understand the new systems and plans in advance of actual 

deployment. 

Special events and work zone projects often have their own public outreach efforts. When 

implementing corridor operations plans and procedures into these types of projects, the public 

outreach should integrate information on the corridor operations systems into the overall special 

event or work zone project outreach campaign. 

New systems and technologies should be field tested under a variety of different conditions and 

scenarios to ensure that the systems will function adequately before actual implementation of the 

corridor operations plans. Participating agencies and departments should make sure they are 

internally ready to operate the systems for which they are responsible. Being ready includes 

ensuring all responsible staff are adequately trained on the plans and procedures and have 

adequate time and resources to complete their responsibilities. Being ready also includes 

notifying affected internal staff, including management, of startup dates and how to respond to 

any questions or complaints from the public (i.e., knowing who the point of contact is for media 

inquiries). 

3.12 Step 10: Operations and Maintenance 

Upon deployment of the corridor operations plans and procedures, as well as the new systems or 

equipment needed to support the plans, it is imperative that agencies use the developed plans and 

procedures to ensure the corridor operates at peak efficiency. The focus of this entire effort is to 

create plans and procedures that can be operated on a daily basis, or when triggered by certain 

scenarios, so operating the corridor should have been adequately planned for and funded by this 

point. 

It is easy, however, for those responsible for operating the corridor systems to lose focus after the 

interest created during the project deployment fades. Daily activity priorities change as new 

projects, plans, and procedures become the new “project of the day.” To address these issues, it 
53 

is important that agencies periodically monitor the activities of system operators to check 

whether the corridor operations plans and procedures are being used as often as they should be 

and as intended. 

A number of operations support tools can also be developed to maximize the efficiency of 

system operators and the plans and procedures used to operate the corridor. Such operations tools 

could consist of: (16)

 Operations checklist—a convenient, easy-to-use reference for system operators that lists all 

action steps necessary under each corridor operations scenario. Such a checklist could be 

based directly on the plans and procedures developed under the plan development in step 8. 

 After hours on-call roster—a roster available to all operators containing the names and 

contact information of individuals to call in cases of emergency. Included in the roster should 

be a schedule of when staff are on-duty and the general types of problems each staff member 

is able to address. 

 Operations logs—records of system activity, when the activity occurred, and whether the 

activity was generated automatically or manually. 

 Agency contacts—names and contact information for partner agencies affected by the 

corridor operations plans. 

 Media procedures—procedures on how to respond to media inquiries, such as when to 

personally field the inquiry, when to refer the inquiry to other points of contact (e.g., public 

relations office), and talking points on the corridor operations plans. 

In addition to operations, the new systems and 

technologies deployed to support corridor operations need 

to be maintained on a regular basis to ensure the systems 

can be efficiently operated (figure 15). Corridor 

operations systems may be complex, integrated 

amalgamations of hardware, technologies, and processes 

for data acquisition, command and control, computing, 

and communication. Accordingly, maintenance can be a 

complex proposition as well, requiring sophisticated 

approaches and advanced technology. Without adequate 

consideration of maintenance, inefficiency will begin to 

develop shortly after implementation of a project. 

 

Maintenance of the systems is a necessity to ensure 

reliability and proper operation, thereby protecting the 

investment and enabling the system to respond to changing conditions. Failure to function as 

intended could negatively impact traffic safety, reduce system capacity, and ultimately lead the 

traveling public to lose faith in their transportation system. Failure of the system also has the 

potential to cause measurable economic loss and increase congestion, fuel consumption, 

pollutants, and traffic accidents. 

 

Maintenance considerations must be an integral part of the process to develop a corridor 

operations program. Considerations for maintenance include involving maintenance 

stakeholders, developing a high-level maintenance plan (including maintenance and replacement 

Figure 15. Photo. Traffic signal 

maintenance crew at work. 
54 

costs in the life cycle analyses), and identifying maintenance functional requirements early in the 

process. In this manner, the coordinated operations effort and any enabling systems will include 

the necessary resources, environment, and procedures to maintain the infrastructure associated 

with the program. 

3.13 Step 11: Continuous Improvement 

As emphasized in figure 6 in chapter 3, continuous improvement is iterative and should take 

place throughout the entire life cycle of a corridor operations project, from planning to design to 

operations and maintenance. Continuous improvement is the process of monitoring the 

conditions in the field to determine whether the corridor operations plans are meeting the original 

corridor goals and objectives. If the goals and objectives are not being met adequately, then 

revisions need to be made to the plans and procedures to meet the goals and objectives. 

The continuous improvement step is often overlooked by agencies in all project types. However, 

it should be considered seriously because it is the only step solely dedicated to ensuring the 

project is a success. Also, the continuous improvement step keeps the project accountable and 

certifies the costs of the project are matched with the highest benefits possible. 

Continuous improvement is done soon after deployment of the corridor operations systems and 

on a regular basis thereafter. For example, the effectiveness of the corridor operations system 

could be checked on a yearly basis. Continuous improvement should be done on a regular basis 

because of the dynamic nature of traffic conditions, staff turnover, changes in agency direction, 

and changes in funding and operations priorities. Because of this dynamic nature, operations 

plans that are highly effective one year may not be the next year. 

If it is determined that it is necessary to re-align the corridor operations closer to the original 

goals and objectives, the corridor stakeholders should first determine how far back in the process 

they should return. The point in the framework to which the stakeholders should return depends 

on the nature of the problem and how far apart the actual conditions are from meeting the goals 

and objectives. Once the framework has been entered again, all the subsequent steps should also 

be reviewed to determine if they are affected. For example: 

 If new agencies need to be involved in the operations plans, then the institutional 

considerations discussed in steps 2 and on should be revisited. 

 If the goals and objectives need to be revised, then steps 3 and on should be revisited. 

 If the corridor concept of operations needs to be expanded or revised due to changes in the 

roadway network, implementation of new systems or technologies, or addition of significantly 

different operations scenarios, then steps 4 and on should be revisited. 

 If new strategies have become possible that could improve corridor operations, then steps 5 

and on should be revisited. 

 If new funding sources have become available that could affect the sequence of projects 

supporting full development of corridor operations, then steps 7 and on should be revisited. 

 If previously effective operations plans have become outdated or are not being used as 

planned, then steps 10 and on should be revisited. 
55 

Overall, the process of coordinating freeways and arterial streets through the established 

framework is never completely finished. Not only will new opportunities arise that will need to 

be addressed within the framework, but refinements to the existing system will also become 

necessary as time passes. As the system is being operated and maintained, the system must be 

continually monitored; it is this monitoring process that will inevitably be the catalyst for setting 

into motion another cycle of the framework. Without such a framework for monitoring 

conditions and continuously improvement, the corridor (and the overall system) will fail to 

perform at optimum effectiveness and efficiency as time passes. 

3.14 Summary 

The reader should now have a thorough understanding of the issues and processes associated 

with achieving coordinated operation of freeways and arterials on a specific corridor through 

implementation of the 11-step CFA operations framework. The next chapter will demonstrate 

how the corridor-level approach can be applied to incident management, work zones, special 

events, and daily recurring operations. While these four categorical areas of traffic operations 

represent areas of emphasis, other traffic issues and problems may also benefit from the 

framework described in this chapter.

57

4 APPLYING CFA OPERATIONS TO FOUR 

OPPORTUNITY AREAS 

4.1 Purpose 

This chapter brings together, as a single process, the concept of corridorwide planning, the use of 

a logical framework for strategy development, and CFA solution deployment from various 

perspectives. Relevant, cost effective technologies for a successful CFA operational deployment 

are assumed as part of the perspective solutions, but CFA supporting technologies and ITS 

systems are discussed at greater length in chapter 5. The four primary opportunities for 

coordinated operations identified in chapter 1 include: 

 Traffic incident management. 

 Work zone management. 

 Planned special events management. 

 Day-to-day or recurring operations. 

Any one or several of the four areas may serve as the launch point for corridor focus and the 

source generating scenarios and solutions. The remainder of this chapter is devoted to applying 

the CFA process to each of these four areas. Methodological repetition is to be expected as each 

category employs the same corridor planning, framework, and enhancing technologies. The 

backbone of the process is the 11-step CFA framework introduced in chapter 2 (figure 6) and 

described in more detail throughout chapter 3. This iterative process applies to each category and 

results in a separate set of action scenarios and strategies. 

4.2 Introduction 

CFA operations is a mindset. This handbook through chapter 4 has developed that mindset into a 

process that integrates operating systems and is enhanced by ITS related technologies. This 

chapter will relate the CFA process specifically to work zones, special events, incident 

management, and day-to-day/recurring operations. The basic concepts and technologies used for 

traffic management and incident management in the context of those systems have been covered 

extensively in many different texts. The same applies to work zone safety and motorist 

protection during highway reconstruction. Even special event planning has been thoroughly 

addressed more recently. Any one of the four areas of traffic management can serve as the 

starting point for developing a CFA approach to regional operations depending on the primary 

concerns and needs of a particular region. By presenting the CFA process from each perspective, 

it is hoped that the reader will recognize not only the different perspective but the essential 

similarity of the CFA mindset, technologies, and shared responsibilities. 

4.3 Traffic Incident Management 

The basics of traffic incident management are well known. There is significant guidance on the 

subject of incident management including Framework for Developing Incident Management 

Systems,

(17) Traffic Incident Management Handbook,(18) Regional Traffic Incident Management 

Programs—Implementation Guide, (19) and the Freeway Management and Operations 
58

Handbook.(20) These materials provide many of the details associated with traffic incident 

management. 

Expanding incident management processes to corridors is the goal of CFA operations. While 

there is no specific formula for the successful development of 

a coordinated traffic incident management plan, the key is in 

the expansion of the scope of incident management from a 

single agency or group of agencies acting in relative isolation 

to a corridor-level approach. Coordinated operations puts the 

available operational elements together in an integrated 

package that focuses on maximum system performance from the users’ perspective. 

While it is possible to plan response scenarios for a variety of incident types and locations, it is 

not possible to plan when and where they will occur. The process is incident-driven rather than 

planned-for as in the other three categories. This significantly different aspect of incident 

management warrants more intensive scrutiny. The critical difference is planned events versus 

unplanned incidents. Corridor incident management, while requiring the same CFA process as 

the other opportunities for coordination, is treated differently from a technology enhancement 

point of view. The primary issues in dealing with corridor incident management are incident 

detection and the need for rapid response. The prompt detection of an incident, the determination 

of its impact on the affected facility and other roadways 

corridorwide, and the execution of a quick, effective response 

are essential. 

While most traffic incidents impact little more than the travel route upon which they occur, more 

significant incidents, both traffic related and otherwise, can have corridorwide travel 

implications. 

The impact of major traffic incidents on the movement of traffic within a corridor can be 

dramatic, causing delays and congestion that overflows onto arterial streets and ramps and even 

increasing the likelihood of additional crashes. The purpose of this section is to reshape the issue 

of incident management coordination with a view toward providing a corridorwide perspective 

on the problem. At the conclusion of this chapter, readers will have an understanding of how to 

expand their approach to traffic incident management coordination from a single project focus to 

a corridorwide management perspective. 

4.3.1 Problem Identification 

Problem identification is the essential first step that sets forth the rationale for exploring 

alternative courses to reduce the magnitude of a problem. Without a clearly defined problem, it is 

impossible to implement a solution that effectively alleviates the basic malfunction of the 

system. The problem definition step also allows the various stakeholders to reach consensus on 

something they all believe constitutes a problem worthy of joint action. Three issues are 

especially important in identifying problems that can be solved by coordinated incident 

management: 

The key is in the expansion of the 

scope of incident management from 

a single agency to an entire 

corridor. 

CFA operations are most beneficial 

under conditions of significant 

supply variations, such as incidents. 
59

 Frequency of incidents by location, time, and weather conditions. 

 Duration and severity of incidents. 

 Traffic impact of incidents. 

As the frequency, duration, and impact of incidents increase, 

corridor incident management becomes more desirable to 

reduce delay and increase safety. Typical problems include 

increased congestion on alternative routes or unnecessary 

delay when alternative routes are available but not effectively 

utilized. 

Incidents will often cause traffic to be diverted off the affected roadway to parallel and other 

alternate routes. If these alternative routes are not operated effectively for the incident-induced 

traffic, delays will occur to both diverting and nondiverting traffic. 

The diversion may take place based on motorist information on the incident route or by the 

actions of individual motorists acting on what they believe to be in their best interests. The 

diversion point and route may lie outside of the jurisdiction experiencing the incident. To 

properly divert traffic to the roadways best able to handle the alternate volume, multiple agencies 

may need to coordinate their efforts. What is best for the mobility and the region as a whole may 

not be realized when diversions take place based on the decisions of individual drivers in 

response to general incident information or the lack of information. 

In assessing current incident response practices from a corridor perspective, the following 

questions may be helpful in identifying problems that are amenable to coordinated incident 

management:(19)

 How well does the corridor perform under normal operating conditions? 

 How well does the corridor perform under incidents? 

 Is there any unused capacity on any of the networks in the corridor? Is this unused capacity 

effectively utilized under current incident conditions? 

 Do mechanisms exist to effectively inform motorists about road conditions on all networks? 

 What is the frequency of incidents that result from diversions? 

 What incident management tasks does each agency now perform? 

 What are each agency’s tasks, responsibilities, and priorities? 

 Are each agency’s task, responsibilities, and priorities well understood among other 

responders and stakeholders when viewed from a corridor perspective? 

 Do any of these responsibilities and priorities conflict? What is the nature of the conflict? How 

can agencies involved in coordinated operations cooperate to resolve the conflicts? 

 Are agencies’ tasks ever redundant? Can coordinated operations free up resources? 

 Are there gaps in delivery of corridor incident management as agency services are now 

configured? 

4.3.2 Institutional Considerations 

The three basic principles of developing institutional relationships were presented in chapter 3. 

They are: 

One of the most challenging issues to 

be resolved among the jurisdictions 

is the sudden increase of traffic in 

the surface street system due to 

diversion from the freeway as a 

result of an incident. 
60

 Establish a structure. 

 Identify corridor stakeholders. 

 Identify corridor champions. 

Incident management is an area that involves multiple agencies and disciplines, and that must be 

executed in real time. It therefore requires the clear delineation of roles and responsibilities, 

which can only be accomplished if an appropriate structure is developed to sustain the effort. The 

type of structure will depend on the local circumstances and, if possible, should build off existing 

relationships and interactions. 

A unique aspect of incident management is the diverse group of individuals or agencies involved 

in it. The complexity of this involvement grows in corridor incident management because both 

the number of agencies engaged and the coordination issues among them increase significantly. 

The following are the types of individuals and agencies commonly involved in incident 

management: 

 Law enforcement. 

 Fire and rescue. 

 Emergency medical services (EMS). 

 Transportation agencies. 

 Towing and recovery service providers. 

 Media. 

 Information service providers. 

 Coroners and medical examiners. 

 Hazardous materials teams. 

These are potential stakeholders in a corridorwide incident management program. To mobilize 

them into an effective coordinated incident management program requires a concerted effort to 

bring them together in new ways that help them perceive the benefits of corridorwide 

coordination. 

It is necessary to have in place some degree of local incident management before initiating 

corridorwide coordination.(21)When no incident management program exists, the first step would 

be to develop a local program. If one agency or jurisdiction has an incident management 

program, start from that point and identify a broader group of stakeholders and build either new 

or expanded relationships that will benefit corridorwide coordination. 

Another challenge is the identification of champions for expanding incident management to a 

corridor-level program. The champions’ support is necessary to secure an initial commitment of 

resources in the form of staff and funding to begin the program development process. 

To achieve the desired outcome, it is necessary to consider the legal and policy environment in 

which coordinated incident management is carried out. Four questions that may be helpful in 

determining this environment include:(19)

Take advantage of attention focused 

on major events (e.g., international 

sporting events, weather events, 

earthquake) to help organize and 

build support for a formal incident 

management program. 
61

1. What are the legal limits to the incident 

response roles that agency personnel can 

perform? (e.g., can an agency leave its 

jurisdiction to aid another jurisdiction?) 

2. To what extent do real or perceived legal 

constrictions pose an obstacle to coordinated 

incident management? 

3. What is the financial liability of agencies, 

agency personnel, and the public with respect 

to joint incident management? 

4. Can or should statutes be changed to facilitate 

coordinated incident management? 

Perhaps the best example of an organization initially formed to address incident management 

problems across jurisdictions is TRANSCOM, as described in section 3.4.(22) A series of 

debilitating incidents in 1986 caused problems on routes adjacent to the incident and led to the 

recognition of the interdependence of facilities and the establishment of TRANSCOM. Here, the 

Port Authority of New York and New Jersey operated as the champion of the effort, providing 

leadership and seed funding. Since then, the organization has evolved and taken on a broader 

role in regional traffic management coordination. 

4.3.3 Goals, Objectives, and Performance Measures 

The goals for corridor incident management are established before working on the detailed 

strategies for the corridor incident management program. This allows the partners to define 

broadly what they are willing to do before defining where and how they will do it. By starting 

with broad goals, the partners can define what aspects of corridor incident management they 

believe they can undertake. This is an important step because not all parties may see goals the 

same way. It is easier to understand conflicts at the goal level because they are general in nature. 

For example, one goal might be: 

 

To mitigate the corridor impact of major incidents on travelers by efficiently using freeway 

and surface street capacity during major incidents. 

A broad goal such as this provides an opportunity for stakeholders to express differences. The 

goal suggests there are opportunities for improvement in incident response on both the arterial 

and the freeway system and that corridorwide action should be limited to major incidents, 

leaving lesser events to the individual agencies. If the arterial management agency is opposed to 

using arterials during incidents, it will become apparent during the drafting of a goal. At this 

point, however, it is not necessary to determine whether there are specific areas for which use of 

alternative routes is unacceptable, just whether the concept is supported in principle. 

The next level of detail is objectives. Specific objectives might include: 

 Assess severity of corridor incidents within 5 minutes. 

 Inform corridor users of incident within 5 minutes. 

Having a neutral meeting space and staff are 

important for creating an equal playing field 

and enhancing trust among participants; but 

meetings alone are not enough. At the 

Greater Houston Transportation and 

Emergency Management Center (TranStar), 

physical co-location of multiple 

organizations, working side by side on a daily 

basis, established trust and created an 

understanding among the agencies of each 

other’s activities, needs, and resources that 

would not be possible from meetings alone. 
62

 Implement diversion plan within 10 minutes. 

 Provide clearance resources through coordinated response with 15 minutes. 

These objectives help shape expectations of what is and is not reasonable from the perspectives 

of the partners. In formulating goals and objectives, the following corridor-based questions 

should be considered: 

 What factors influence corridor incident management? How can they best reflect the corridor 

goals and objectives? 

 What are the corridor’s greatest unmet needs with respect to incident management? 

 How can corridor incident management goals and objectives be framed such that they reflect 

the mission, roles, and priorities of all the corridor incident management team members? 

 Are there political factors (e.g., certain stakeholders that will be opposed to diverted traffic) 

that need to be addressed? 

Typical incident response performance measures (generally measured in minutes) to be used for 

incident management include: 

 Detection time. 

 Response time 

 Clearance time. 

 Time-to-traveler notification. 

 Travel delay time. 

 Throughput reduction. 

 Related secondary incidents. 

It is also possible to estimate reductions in delays based on the frequency, location, and duration 

of incidents. However, this requires more extensive analysis than would be typically undertaken. 

Corridor incident management is not significantly different from agency incident management. 

However, in developing a corridor program, the coordinated response may be limited to more 

significant incidents. It is also useful to understand that excess capacity is more likely to occur 

during off-peak conditions. For example, a major truck accident at night may be more effectively 

addressed by an alternative route because the volume of affected traffic and the volume of traffic 

on alternative routes are likely to be less. 

4.3.4 Corridor Concept of Operations 

The corridor concept of operations is a formal document that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed in part to help communicate this view to 

the other stakeholders and to solicit their feedback. The corridor concept of operations provides a 

description of the current system, operating practices and policies, and existing capabilities. It 

lays out the program concept, explains how the corridor system is expected to work once it is in 

operation, and identifies the responsibilities of the various stakeholders for making this happen. 

The goals, objectives, and performance measures of a proposed operation are also documented. 

The process of developing a concept of operations for a corridor should involve all stakeholders 

and serve to build consensus in defining the goals and objectives; to provide a description of how 
63

functions are currently performed, thereby supporting resource planning; and to identify the 

interactions between organizations. 

The basis of the corridor incident management concept of operations is the development of highlevel problematic issues, which warrant corridor-level incident response. These issues are 

developed from the defined problems identified in the first step in the framework. Those 

problems that are identified and whose mitigation is consistent with the corridor goals and 

objectives would be candidates for mitigation. Those problems that merit mitigation would be 

developed into high-level problematic issue statements. 

Problematic issues represent the initiating event for mitigation of the effects of incidents. At the 

concept of operations stage, problematic issues are high-level and do not focus on specific 

locations. One such issue would be a major incident on a freeway that would activate diversion 

plans involving traveler information, revised traffic signal control, and the initiation of a 

coordinated agency response. 

At this stage, the cooperating agencies answer the questions of what (not how) they would be 

willing to do in the corridor in regard to coordinated operations in response to an incident. 

General strategies would include: 

 Provide traveler information. 

 Establish traffic management and control. 

 Share information and resources. 

For example, a high-level problematic issue might be an incident on a busy parallel arterial 

street. The general strategy might be to use existing freeway DMSs to alert freeway drivers to the 

incident so they may choose to stay on the freeway and/or seek an alternative route. Another 

general strategy might be to provide special arterial signal timing when major incidents occur on 

the freeway. 

The development of a concept of operations will allow the participating agencies to agree on 

what they wish to accomplish and to lay the framework for how that will be done. For example, 

does the traveler information only describe the nature of the problem or does it provide 

recommended courses of action? This is an example of an issue the agencies have to work out 

before moving to the more detailed level of discussion. This step sets the general ground rules 

for coordinated response. 

As part of the development of a concept of operations, consider the following points: 

 Does stakeholder consensus exist to support coordinated incident management? 

 If not, does it exist for other types of situations such as special events or major construction 

and maintenance operations? 

 If so, could success in the other situations be used to develop a coordinated incident 

management program within the region? 

 If stakeholder consensus must be established, who will be the champion and organize a 

workshop or forum to demonstrate the benefits? 

 What is the level of stakeholder commitment to contributing personnel and funding resources? 
64

 What policy changes, if any, are needed to implement a coordinated incident management 

program (such as quick clearance legislation, liability protection, and so forth.)? 

 What organizational structure will be established for the day-to-day incident management 

program? 

As discussed more fully in section 3.6, the concept of 

operations document that results from this development 

process could include sections on the following topics: 

 Scope. 

 Resources. 

 A user-oriented operational description. 

 Identification of operational needs. 

 A system overview. 

 Description of the operational and support environment. 

 Development of operations scenarios. 

The concept of operations defines the general scenarios that will be used to address the identified 

problems and is consistent with the corridor goals and objectives. Activation criteria and the 

types of response, specific scenarios, and strategies will ultimately be worked out in the design 

and development step. The key to successful concept of operations development is remembering 

that this step involves the “who, what, when and where” of incident management. The corridor 

plan will determine how these details will be implemented. 

4.3.5 Corridor Scenarios and Operations Strategies 

Once the concept of operations is agreed to, scenarios and potential strategies need to be refined. 

Specific questions need to be addressed, such as: 

 In what segments of highway and under what conditions are strategies to be implemented? 

 What are the potential strategies that might be implemented to mitigate each scenario? 

The concept of operations scenarios need to be developed for specific locations where corridor 

incident management would be implemented. For example, freeway and arterial segments where 

the frequency of incidents causes significant corridorwide congestion need to be identified. This 

identification process is done best with the involvement of all the corridor partners to incorporate 

the widest possible perspective of the problem and to develop a sense of engagement among the 

implementing partners. 

The process of selecting scenarios is somewhat iterative with the strategies to be implemented. 

For example, if strategies include alternative routes, the scenarios need to reflect the logical 

points at which diversions might be implemented. 

Strategies are specific actions to mitigate one of the scenarios associated with a corridor incident. 

Several strategies may be required to achieve the desired improvement in system performance. 

The strategies may also vary by the severity of the incident. 

The key to successful concept of operations 

development is remembering that this step 

involves the “who, what, when and where” 

of incident management. 
65

Individual agencies might consider the following examples of candidate strategies to achieve 

improved corridor operation: 

 Notify potentially affected agencies of incidents. 

 Provide traveler information via resources such as DMS, HAR, and the media. 

 Advise affected motorists to use an alternate route. 

 Advise motorists to use a particular alternate route. 

 Implement traffic signal timing adjustments. 

 Provide mutual-aid sharing of in-field incident response teams. 

 Implement access control strategies (e.g., lane closures, turning restrictions, lifted high 

occupancy vehicle (HOV) restrictions, and so forth). 

Shared resources represent one of the potential major benefits of coordinated operations, 

especially during major incidents. Most agencies cannot provide sufficient staff and resources to 

deal with unusually large incidents; however, through shared resources, collaborating agencies 

can make available many more resources than they could individually provide. Since a major 

incident often has substantial spillover effect, shared resources are a win-win proposition for all 

stakeholders involved. 

At this point the strategies are still general ideas of how agencies can work together, but are 

being focused on specific segments of roadway. In the next step, the strategies are analyzed in 

more detail to identify practical considerations as well as costs and potential benefits. The 

current objective is to consider taking traditional strategies beyond agency boundaries to improve 

corridor operation. What is possible technically and what is possible practically? The answers 

will depend on many local factors. The important point is to begin the dialogue among partners 

to determine what is possible. 

4.3.6 Evaluation and Selection of Strategies 

The process of selecting specific strategies is an iterative process involving the stakeholders in 

assessing both the costs and the benefits of the strategies and the various agencies’ ability to 

implement them. A strategy may be perceived to be positive initially, but a more detailed 

analysis may show it to be counterproductive. A strategy may be technically feasible, but beyond 

the resources available or inconsistent with other community values. 

As the stakeholder group considers specific strategies, the following issues will ultimately come 

under discussion: 

 Roles, responsibilities, and procedures. 

 Infrastructure needs and costs. 

 Operating and maintenance resources and costs. 

 Analysis of numerous alternative strategies and selection of the best one(s). 

 Ability of candidate strategies to meet the goals and objectives for the corridor. 

Each of the agencies must be comfortable with the strategies and be capable of implementation. 

The degree of sophistication of the strategies will depend on the current capabilities of the 

agencies and the degree to which the agencies desire to invest in technology and/or staffing to 

achieve better operations. 
66

The evaluation of strategies may vary from qualitative to quantitative methods. Integrated 

traveler information may be evaluated qualitatively because the impacts are difficult to assess 

and the potential for problems minimal. A strategy to divert traffic from the freeway to a parallel 

arterial should involve adequate quantitative analysis to avoid creating a larger problem than the 

one being resolved. In some cases, more sophisticated tools such as simulation models may be 

required to determine the feasibility and appropriateness of a strategy. 

The process of selection may be simple or complex depending upon the nature of the problem 

being addressed and the need for quantification of benefits. In some cases, the strategies may be 

more dependent upon consensus among the stakeholders than analytical analysis. 

The following are some possible items to consider before diverting traffic either from a freeway 

to an arterial, or from an arterial to a freeway: 

 Is there sufficient signage to ensure travelers do not get lost? 

 Is there sufficient trailblazing on the alternate route? 

 Does the arterial have the capacity to handle the diverted traffic? Can it, with signal timing 

changes? 

 Can signals be changed easily from a remote location? Is there sufficient arterial surveillance 

capability to closely monitor the diversion? 

 Are there effective connectors? Can these be effectively monitored? 

 Are there liability issues in suggesting alternate routes? 

 Are temporary turning or parking restrictions needed on arterial routes? If so, is it possible to 

deploy manual resources to erect appropriate signing and/or implement such changes safely 

and in a timely manner? 

 Are there permit or utility operations that have been deployed without prior notice? 

 Is there roadwork in place along the diversion route and, if so, can it be removed quickly? 

 Are there any special events along the diversion route which may hinder traffic? 

 Are there schools or hospitals on the alternate route? 

 Are there major employment centers or shopping malls on the diversion route? 

In planning the operational strategies to be used during incidents, there are questions which 

should be considered, such as: 

Is the incident on the freeway or the arterial street? 

There are a number of differences depending upon where 

the incident occurs. If the incident is on the freeway and 

traffic is diverted to the arterial street, the local agency 

operating the arterial needs to be aware of the diversion 

and should take steps, such as a survey of the arterial 

street, to assure traffic is hindered as little as possible. Adjustments to signal timing, removal of 

temporary roadwork, and other steps can also facilitate traffic diversion. If the incident takes 

place on the arterial street and traffic is diverted to the freeway, there are probably fewer 

considerations, but notifications still need to be made and adjustments, such as changes to ramp 

metering, may have to take place. 

It may be preferable for safety reasons not 

to designate roads containing schools, 

hospitals, parks, or residential areas as 

alternative routes as they may have speed 

restrictions or speed control devices 

installed (e.g., speed humps). 
67

What time of day and on which day of the week did the incident take place? 

An incident occurring on a weekend will have a different response from one taking place on a 

weekday. For example, schools along the alternate route will not be open on Saturdays and 

Sundays, but traffic to a shopping district will be heavier. The time of day will also have an 

impact: incidents during peak periods will cause even greater congestion than is typically 

experienced. Available resources, especially staffing, will vary depending upon the time of the 

incident. 

What capacity loss does the incident present? 

An incident which occurs in the early morning hours and shuts down one lane of a three-lane 

highway will present a minor loss of capacity and it may not be necessary to implement any 

coordination between the freeway and arterial street operators beyond notifications. At the other 

extreme, a full closure of either the arterial street or the freeway may force a diversion between 

the roadways. 

What is the cost of various coordination efforts? 

Most actions, beyond notifications, carry some cost to the agencies responsible for carrying them 

out. For example, if a city must deploy police officers to direct traffic manually at diversion 

points or through intersections, there is a significant cost for supplying that labor. Issues of who 

pays for what should be worked out ahead of time so that concerns about cost do not delay 

implementation of plans during an incident. 

What resources are available? 

Knowing ahead of time what resources can be used allows the agencies to improve coordination 

of their efforts and to determine what level of response is appropriate. Permanent DMSs can be 

easily adjusted with messages displayed even for incidents of short duration. On the other hand, 

if portable signs need to be deployed, agency personnel must consider whether the time and 

effort to retrieve the signs, transport them to the location, and program messages is worth the 

effort given the expected duration of the incident. 

Upon completion of this step of the process, all stakeholders should have a detailed 

understanding of what strategies are feasible and supported by the corridor agencies. The next 

step is to package all of the strategies in a corridor implementation plan, which is a formal 

document that can be used to secure the funding necessary to advance the program to design. 

4.3.7 Corridor Implementation Plan 

The corridor implementation plan is the final product of the decisionmaking segment of the CFA 

operations framework. It documents all the steps previously undertaken with sufficient detail to 

see the project or projects developed for improved corridor operations through implementation. 
68

The corridor implementation plan would include the following elements: 

 Goals and objectives for corridor. 

 Summary of corridor concept of operations. 

 Summary of corridor scenarios and selected operations strategies. 

 Phasing of efforts or projects necessary to implement operations strategies. 

 Staffing and personnel needs. 

 Capital, operating, and maintenance costs. 

 Potential funding sources. 

 Schedule for corridor implementation. 

Multiple scenarios are developed for the the package of operations plans, which forms the basis 

of the corridor implementation plan. To implement the operations plans requires an assessment 

of the resources required for the implementation phase of the framework (design, deployment/ 

implementation, and operations and maintenance). The corridor implementation plan compiles 

the operations plans and the necessary supporting resources in a complete package that can be 

used to secure the funding necessary for design, implementation, and operation and maintenance. 

The plan is also needed to provide documentation for securing the institutional consensus 

necessary to proceed. 

In summary, after the concept of operations, the corridor implementation plan is the second 

major milestone. It is a formal document that contains sufficient detail to move the plan to the 

next step, which is design and development, and may contain a number of projects, especially if 

it is necessary to fund and construct the implementation over a long timeframe. The plan would 

also indicate priorities among projects, potential funding sources, and cost allocations. 

4.3.8 Design and Development 

The design and development step initiates the implementation phase of the framework. The 

design transforms corridor implementation plan concepts into practice and covers many details, 

including the construction plans necessary to build the supporting infrastructure and the detailed 

procedures and supporting agreements necessary to operate and maintain the operations plans. 

The issues to be addressed in the design phase include: 

 Performance requirements. 

 Functional requirements (what is trying to be accomplished). 

 System architecture (how does the system work). 

 Identification and screening of technologies. 

 Specifying technologies. 

The important aspect of the design phase is that it requires 

selection of the technologies that are necessary to support 

the operations plans included in the corridor 

implementation plan. The specifics will be highly 

individualized because of the variety of ways in which 

individual agencies work and the amount of sharing of 

information and control that is acceptable. Under a loosely 

When more than one agency is involved 

in the funding and development of a 

system, a memorandum of understanding 

(MOU) may be necessary to dictate 

which agencies are responsible for the 

maintenance of each component of the 

system. 
69

integrated system, control system changes could be implemented by a telephone call requesting a 

special timing plan. Under a closely integrated system, an agency with a 24/7 operation might be 

able to implement preplanned strategies when the agency owning the equipment is not staffed for 

operation. 

The design phase also calls for development of specific details of the strategies to be 

implemented, similar to those noted in figure 16. This would include details like loading specific 

messages onto DMSs and creating signal timing plans for coordinated diversion routes. This is 

where development of plans and procedures are made for each strategy that was selected earlier. 

These plans are then packaged into a separate operations plan for each scenario. Specific 

procedures are created for each plan to define roles and responsibilities. See chapter 3 and figure 

13 for more information. 
70

Figure 16. Chart. Example of operations plans and procedures for 

incident management scenarios. 

Scenario 3

Scenario 2

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Scenario 1

Activation Matrix

Off Peak 

AM, PM 

Peaks

Right two 

lanes stopped

Right lane 

stopped

All traffic 

stopped

Scenario

1A

Scenario

1D

Scenario

1E

Scenario

1F

Scenario

1B

Scenario

1C

Criteria

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

DMS Messaging

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Signal Timing

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Shared Information Lane Assignments

Corridor Operations Strategies

Operations Plans

Plans

1D 1F 1E

DMS-1

ST-1

SI-1

LA-1

Scenario 1B 1A 1C

DMS-2

ST-2

SI-2

LA-1

DMS-3

ST-3

SI-3

LA-1

DMS-2

ST-2

SI-2

LA-1

DMS-3

ST-3

SI-2

LA-2

DMS-3

ST-3

SI-3

LA-3

DMS-2

ST-2

SI-2

LA-1

Plans

Scenario

Operations Plans

DMS-1

ST-1

SI-1

LA-1

1A Action Steps Agency 1B

Operations Procedures

1, 2, 3...

A, B, C...

....

....

DOT

City

DOT

City

Scenario 3

Scenario 2

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Scenario 1

Scenario 3

Scenario 2

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Scenario 1

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Heavy congestion on I—5 

northbound between mileposts 

50 and 60

Scenario 1

Activation Matrix

Off Peak 

AM, PM 

Peaks

Right two 

lanes stopped

Right lane 

stopped

All traffic 

stopped

Scenario

1A

Scenario

1D

Scenario

1E

Scenario

1F

Scenario

1B

Scenario

1C

Criteria

Activation Matrix

Off Peak 

AM, PM 

Peaks

Right two 

lanes stopped

Right lane 

stopped

All traffic 

stopped

Scenario

1A

Scenario

1D

Scenario

1E

Scenario

1F

Scenario

1B

Scenario

1C

Criteria

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

DMS Messaging

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Signal Timing

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Shared Information Lane Assignments

Corridor Operations Strategies

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

Plan DMS-1: Freeway DMS messages

Plan DMS-2: Freeway and arterial DMS 

messages

Plan DMS-3: DMS active route guidance

DMS Messaging

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan SI-1: Standard procedure 

Plan SI-2: TMC operator phones city 

engineer

Plan SI-3: TMC operator controls city 

signals

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Plan ST-1: Standard timing plan

Plan ST-2: Light diversion plan

Plan ST-3: Heavy diversion plan

Signal Timing

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Plan LA-1: No changes

Plan LA-2: Convert turn lane into 

through lane.

Plan LA-3: Temporarily close key 

onramps

Shared Information Lane Assignments

Corridor Operations Strategies

Operations Plans

Plans

1D 1F 1E

DMS-1

ST-1

SI-1

LA-1

Scenario 1B 1A 1C

DMS-2

ST-2

SI-2

LA-1

DMS-3

ST-3

SI-3

LA-1

DMS-2

ST-2

SI-2

LA-1

DMS-3

ST-3

SI-2

LA-2

DMS-3

ST-3

SI-3

LA-3

DMS-2

ST-2

SI-2

LA-1

Plans

Scenario

Operations Plans

DMS-1

ST-1

SI-1

LA-1

1A Action Steps Agency 1B

Operations Procedures

1, 2, 3...

A, B, C...

....

....

DOT

City

DOT

City

DMS-2

ST-2

SI-2

LA-1

Plans

Scenario

Operations Plans

DMS-1

ST-1

SI-1

LA-1

1A Action Steps Agency 1B

Operations Procedures

1, 2, 3...

A, B, C...

....

....

DOT

City

DOT

City
71

4.3.9 Deployment 

The deployment phase includes activities in preparation for implementation and the various 

actions necessary to implement the system designed in the previous step. 

Some of the following activities may be required prior to implementation: 

 Execution of any interagency agreements. 

 Execution of any policies such as “Move It” or “Quick Clearance.” 

 Procuring other resource staff. 

 Training staff. 

The implementation process may involve both people and infrastructure. There may be new staff 

that needs to be hired and trained. As the complexity of the project increases, phasing and timing 

of the various elements needs careful consideration so that the system components can be 

deployed and tested in a timely fashion. 

In the development of most CFA deployments, it is anticipated that the majority of activities will 

involve integration and enhancements of disparate monitoring and control systems. Given the 

assumption of integration, consideration should be given to adopting ITS standards whenever 

possible in the deployment process. 

4.3.10 Operations and Maintenance 

Overlooking operations and maintenance often results in serious negative consequences. Without 

ongoing support for a project, its potential cannot be 

achieved; therefore, operation and maintenance must 

become a part of the routine operation of the agencies. 

To achieve this, it may be necessary to designate an 

individual to handle the coordination of the unique 

requirements of shared operations and management of the corridor. Given the irregular 

frequency of incidents, there may be substantial cost savings in integrating incident management 

responsibility. 

4.3.11 Continuous Improvement 

Continuous improvement should be well integrated into the overall process. The performance 

monitoring system should provide feedback on both the success of individual operations plans 

and the need for other actions. In addition, regular meetings facilitate ongoing communications. 

These meetings would address both experiences and lessons learned from coordinated operations 

and refine existing operations. An annual meeting to review the program more broadly regarding 

overall operations plans would also be desirable. This is particularly critical for corridor incident 

management as many of the response strategies are difficut to develop. For example, diversion 

volume and corresponding signal timings must first be estimated based solely on projected 

demands. Once the sytem has been in actual operations, these operations plans can be calibrated 

and upgraded. 

Assigning full responsibility and authority 

to the program manager usually facilitates 

success of a large technical project. 
72

4.4 Work Zone Management 

It is often the case that a work zone has a ripple effect on transportation within a corridor, 

particularly when they lie within high-traffic areas or areas that are subject to extreme a.m. or 

p.m. peak movements. The purpose of this section is to recast the issue of work zone 

management in the context of the coordinated freeways and arterials framework. At the 

conclusion of this section, the reader will have an understanding of how to expand their approach 

to work zone coordination from a single project focus to a corridorwide management 

perspective. 

The impacts of work zones are not always restricted to 

the work zone itself. These impacts may be felt in the 

area in advance of the work zone, in other roadway 

corridors, within the regional transportation network, 

and on other modes of transportation. It is important to understand that the types of strategies 

deployed may change based on the duration of the operation. 

Expanding work zone management processes to corridors is the goal of CFA operations. There is 

no magic formula for development of coordinated work zone management; the key is to expand 

the scope of work zone management from a single project focus to a corridor management view. 

A view that focuses on maximum system performance from the users’ perspective by 

minimizing the overall effects of the work zone is essential. 

4.4.1 Problem Identification 

The following factors help define the work zone problems that should be addressed: 

 Type of work zone operation. 

 Duration and severity of work zone. 

 Impact of work zone on surrounding traffic operations. 

Type and duration of work zones can have a potentially significant corridor impact. However, it 

is also important to understand the potential impact of multiple work zones on each other. Often 

individual work zone projects would have modest impact on travelers if it were not for another 

work zone that either compounds the principal delay or affects alternative routes. 

The type and duration of work zones affects both the extent of the potential problems and the 

potential remedies. The longer and larger the work zone, the more likely that mitigation efforts 

will be cost effective. The Manual on Uniform Traffic Control Devices classifies work zone 

operations as follows:(23)

 Long-term stationary— work that occupies a location for more than 3 days. 

 Intermediate-term stationary— work that occupies a location for more than 1 daylight period 

up to 3 days or nighttime work lasting more than 1 hour. 

 Short-term stationary— daytime work that occupies a location for more than 1 hour but less 

than 12 hours. 

A view that focuses on maximum system 

performance from the users’ perspective by 

minimizing the overall effects of the work 

zone is essential. 
73

 Short duration—work that occupies a location up to 1 hour. 

 Mobile— work that moves intermittently or continuously. 

The important point to derive is that the impact of work zones can vary from large projects that 

impact an entire city to smaller projects to a daily pothole patching crew on the local freeway. 

This section focuses on work zone projects that impact both freeway and arterial operations. 

In assessing current work zone practices from a corridor perspective, the following questions 

may be helpful in identifying problems that are amenable to coordinated work zone 

management: 

 Do agencies share information on planned activities? 

 What are each agency’s practices for work zone management? 

 Are each agency’s practices and priorities well understood among other stakeholders when 

viewed from a corridor perspective? 

 Do any of these practices and priorities conflict? What is the nature of the conflict? How can 

agencies involved in coordinated operations cooperate to resolve the conflict? 

 Are agency’s practices redundant? Can coordinated operations free-up resources? 

 Are there gaps in delivery of corridor work zone management as agency services are now 

configured? 

4.4.2 Institutional Considerations 

The basic principles of developing institutional relationships were presented in chapter 3. Those 

principles are: 

 Establish a structure. 

 Identify corridor stakeholders. 

 Identify corridor champions. 

Work zone management is an area that involves multiple agencies and disciplines and therefore 

requires the clear delineation of roles and responsibilities. An appropriate structure must be 

developed to sustain the effort. The type of structure depends on local circumstances and should 

build, if possible, on existing relationships using any of the structures described in chapter 3. 

To advance a large project from inception through implementation may require the organization 

of executive, steering, and operation committees that will need to be informed throughout the 

various stages of the project. 

The key stakeholders that need to be involved in work zone operations fall into the following 

categories: 

 State and local political leadership. 

 Intra-agency personnel such as planning, design construction engineering, and public 

information staff. 
74

 Interagency personnel. 

o Law enforcement and emergency management agencies. 

o Local public works departments. 

o Transit agencies. 

 Managers of special event venues. 

 Major employers and/or traffic generators. 

 Media. 

To mobilize these individuals and agencies into an effective CFA work zone management 

program, a concerted effort is required to bring them together in new ways to realize the benefits 

of corridorwide coordination. 

It is necessary to have in place some degree of work zone management to implement a 

coordinated program. Agencies wishing to assess their work zone management practices may 

wish to take FHWA’s Work Zone Mobility and Safety Self-Assessment Guide.

(24) This tool allows 

agencies to judge their own programs’ achievements and to identify areas for improvement. 

If no work zone management program exists, the first step is develop a local program. Assuming 

at least one agency or jurisdiction has a work zone management program, the next step is to 

expand work zone management beyond traditional agency or jurisdictional boundaries. The 

process requires identification of a broader group of stakeholders and either building new 

relationships or expanding established relationships. 

To achieve the desired outcome, it is necessary to consider the legal and policy environment in 

which coordinated work zone management is carried out. Questions that may be helpful in 

determining this environment include: 

 What are the legal limits to work zone management that agency personnel can perform? (e.g., 

can an agency leave its jurisdiction to aid another agency in its jurisdiction?) 

 To what extent do real or perceived legal constrictions pose an obstacle to coordinated work 

zone management? 

 What is the financial liability of agencies, agency personnel, and the public with respect to 

joint work zone management? 

 Can or should statutes be changed to facilitate coordinated work zone management? 

The remainder of this section highlights the unique issues of CFA management, which extends 

the principle of local work zone management to a larger venue. The first challenge is to identify 

champions for expanding work zone management to a corridor-level program. The champions’ 

support is necessary to secure an initial commitment of resources (staff and funding) to begin the 

program development process. It ensure success, champions must emerge or be identified as part 

of the coalition-building process. The champions guide the project from inception to completion 

and help navigate through the institutional challenges. 
75

4.4.3 Goals, Objectives, and Performance Measures 

Goals, objectives, and performance measures should be developed based on the consensus of the 

stakeholders to establish a unified foundation for developing CFA operations during work zones. 

CFA operations specifically for work zones should address the following key goals: 

 Maximize worker safety. 

 Maximize worker productivity. 

 Minimize impacts on travelers. 

 Reduce project duration. 

 Achieve cost efficiency. 

It can sometimes be difficult to reach a balance between these goals. A full roadway closure 

would achieve four of the five goals, but would generally not be considered because of the 

inconvenience to the public. However, even full roadway closures are now being considered. An 

example of implementation of a full lane closure project and can be found at: 

http://ops.fhwa.dot.gov/wz/workshops/accessible/LaRue_paper.htm. 

In addition, special considerations to minimize the impacts of work zone operations on response 

time by emergency management services needs to be addressed. Once the goals have been 

established, specific objectives can be defined to reflect the various perspectives of those 

impacted by work zone activity, such as the traveling public, work zone workers, and the 

responsible jurisdiction(s). Table 7 is an example of work zone objectives. 

Table 7. Example objectives for work zones. 

Perspectives Work Zone Objectives 

Traveler Travel delay no greater than X percent. 

Maintain normal access for local residents and businesses. 

Maximum travel times through primary freeway corridor to 

not exceed X hours. 

Workers No work zone-related fatalities or injuries. 

Jurisdiction Achieve crash rate no higher than exists without work zone. 

Allow emergency vehicles to access work zone and travel 

through work zone as quickly as possible. 

The determined goals and objectives will influence the work zone sequence and impact the types 

of strategies considered to improve the CFA. The most important performance measure from the 

traveler perspective is any delay that the work zone operation will have on their trip. While the 

public understands that delays are likely from a work zone operation, there is a limit to what will 

and will not be tolerated. 

The development of goals and performance measurement for work zone operations is also an 

evolving area. Areas for potential goal setting and performance measure are: 
76

 Planning. 

 Mobility. 

 Safety. 

 Throughput. 

Planning should address such issues as coordination across agencies, projects, and time, as well 

as a consideration of work zone implications throughout the project life cycle. 

Mobility measures should include a consideration of impacts through the whole life cycle 

(before, during, and after a work zone) on all modes of transportation (multimodal) throughout 

the affected corridor (corridorwide). Mobility also addresses the availability of useful and 

reliable information to travelers and operating agencies and the use of ITS technology to measure 

performance, provide information, and manage traffic. 

Safety measures will promote continuous review of work zone design and management, and the 

reduction of accidents and fatalities through efforts to maximize work zone safety management. 

In summary, the goals of an effective CFA work zone project would include maximum safety 

and minimum disruption to travelers. To achieve such goals, a broad view of the interactions of 

various decisions, especially those caused by a lack of coordination between agencies, must be 

considered. 

4.4.4 Corridor Concept of Operations 

The corridor concept of operations is a formal document that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed in part to help communicate this view to 

other stakeholders and to solicit their feedback. The corridor concept of operations provides a 

description of the current system, operating practices and policies, and existing capabilities. It 

lays out the program concept, explains how the corridor system is expected to work once it is in 

operation, and identifies the responsibilities of the various stakeholders for making this happen. 

The goals, objectives, and performance measures of a proposed operation are also documented. 

The process of developing a concept of operations for a corridor should involve all stakeholders 

and serve to build consensus in defining the goals and objectives; to provide a description of how 

functions are currently performed, thereby supporting resource planning; and to identify the 

interactions between organizations. 

The formality of a concept of operations will depend on the nature of the work zone activity. 

Short-term work zones will not usually warrant a complex concept of operations. However, a 

generic concept of operations may be appropriate for walking through the issues and alternatives 

associated with short-term work zones. Guidance on best practices which can form the basis for 

developing a concept of operations may be found at: 

http://ops.fhwa.dot.gov/wz/practices/best/Default.htm. 

Long-term work zones associated with major construction or reconstruction projects requiring 

months or years to complete warrant the development of a more complex concept of operations. 

The operations plan provides a package of strategies associated with one or more specific 

scenarios. 
77

In the case of minor work zone activities (e.g., mobile, short duration, or short-term stationary 

work zones as defined in section 4.4.1), providing traveler information, scheduling during offpeak hours, and coordinating work zones activities between agencies may be all that is 

necessary. The development of a corridor work zone Web site can be a simple means to 

achieving coordinated agency activities and dissemination of traveler information. More 

extensive work zone activities may necessitate more active traffic management and control as 

well as more extensive resource sharing. 

At this stage, the cooperating agencies should address questions of what (not how) they are 

willing to do regarding coordination of work zone activities in the corridor. Perhaps the biggest 

opportunity for improvement of work zone operations is coordination between agencies at the 

planning stage of work zone projects. Avoiding projects that have overlapping impacts could 

substantially reduce traveler delay with a very modest investment in resources. Other general 

strategies to be considered include: 

 Traveler information. 

 Traffic management and control. 

 Shared information and resources. 

The development of a concept of operations allows the participating agencies to agree on what 

they wish to accomplish and to lay the framework for how it will be done. For example, are the 

agencies willing to discuss their schedules for construction projects? This is an issue agencies 

should resolve before moving to the more detailed level of discussion. 

As part of the development of a concept of operations, consider the following points: 

 Does stakeholder consensus exist to support coordinated work zone management? If so, does 

it exist for both short-term and long-term activities? 

 If stakeholder consensus must be established, who will be the champion and organize a 

workshop or forum to demonstrate the benefits? 

 What is the level of stakeholder commitment of personnel and funding resources? 

 What policy changes, if any, are needed to implement a coordinated work zone management 

program (such as legislation regulating short-term work zone activity)? 

 What organizational structure will be established for the day-to-day management program? 

The concept of operations document could include the following sections: 

 Summary of the overall goals of work zone management. 

 Description of the corridor and the stakeholders. 

 Description of the high-level problematic issues. 

 Description of activation criteria. 

 Description of types of strategies to be implemented. 

 Identification of roles and responsibilities of stakeholders. 

 Identification of polices and procedures that require modification. 

 Estimate of capital and operating costs. 

 Identification of schedule for planning, development, and implementation. 
78

In summary, the concept of operations defines the overall plan that addresses the goals and 

objectives of work zone management coordination, the high-level scenarios to be addressed, the 

activation criteria, and the type of response. The concept of operations phase of planning 

involves the “who, what, when, and where” of work zone management. 

4.4.5 Corridor Scenarios and Operations Strategies 

The concept of operations provided the high-level scenarios to be addressed and a general 

discussion of the types of strategies to be implemented to achieve agency support. Once the 

concept of operations is agreed to, the scenarios and potential strategies need to be refined. 

Specifically, what segments of highway and under what conditions are strategies to be 

implemented? What are the potential strategies that might be implemented to mitigate each work 

zone scenario? The concept of operations scenarios need to be developed into specific locations 

where work zones would be implemented. For major construction projects, the location would be 

project specific. For short-term work zones, the scenarios would be more generic, focusing on 

freeway or arterial sections having similar strategies regardless of a specific work zone location. 

The process of selecting scenarios is conceptually linked to the strategies selected for 

implementation. For example, if strategies include alternative routes, the scenarios need to reflect 

the logical points at which diversions might be implemented. 

Strategies are specific actions to mitigate one of the scenarios associated with a work zone. 

Several strategies may be required to achieve the desired improvement in system performance 

and would vary by the duration and impact of the work zone. 

Specific examples of candidate strategies that individual agencies might consider to achieve 

improved corridor operation include: 

 Notify affected agencies regarding work zone activity. 

 Provide traveler information via resources such as DMS, HAR and media. 

 Advise affected motorists to use an alternate route. 

 Advise motorists to use a particular alternate route. 

 Implement traffic signal timing adjustments. 

 Work with corridor employers to investigate potential travel demand strategies (e.g., flextime, 

telecommuting). 

 Expand incident management capabilities for large, long-term projects to preserve remaining 

capacity. 

 Construct temporary park and ride lots to encourage transit alternatives. 

At this point, the strategies are still high-level, general ideas of how agencies can work together 

but focused on specific segments of roadway. In the next step, the strategies are analyzed in more 

detail to understand practical issues such as costs and potential benefits. The current objective is 

to consider taking traditional strategies beyond agency boundaries to improve corridor operation. 

What is possible technically, and what is possible practically? The answers will depend on many 

local factors. The important point is to begin the dialogue among partners to determine what is 

possible. 
79

The opportunities for corridor work zone management coordination need to reflect the unique 

characteristics of incidents. At the corridor level, the two issues that need to be considered are 

timeframe and significance of benefits relative to the effort. 

Short-duration work zones coordination, unless having major capacity reductions, may warrant 

only the dissemination of traveler information. A coordinated traveler information program can 

easily be implemented at virtually no additional cost or effort within an agency-specific program. 

As the severity (amount of capacity reduction) and duration of a work zone increases, the 

potential benefits of more aggressive strategies increase. 

An example of some operations strategies that might be applied to work zones are shown in 

table 8. Because work zones vary in duration, it is important to understand the impact of time on 

the deployment of specific strategies. 

Table 8. Example operations strategies for work zones. 

Category Example Strategies 

Traffic Management and Control 

Freeway management 

Ramp closures. 

Elimination of weaving areas. 

Ramp metering timing and coordination. 

Arterial management 

Access and turn restrictions. 

Advance signing to improve traffic circulation. 

Traffic signal timing and coordination. 

Lane control use adjustments. 

Road closures. 

Onstreet parking restrictions. 

Trailblazer signing. 

Traveler Information 

En route traveler information 

DMS (temporary and permanent). 

Trailblazer signing. 

Pagers, PDAs. 

CB Radios. 

Cell phone/511. 

HAR. 

Media. 

Pretrip traveler information 

Internet. 

Telephone information systems. 

Public information campaign. 

Media (radio and television broadcasts). 

Kiosks. 
80

Table 8. Example operations strategies for work zones (continued). 

Category Example Strategies 

Shared Information and Resources 

Incident response 

Motorist service patrols. 

Wreckers. 

Portable DMS.

Traffic surveillance 

CCTV systems. 

Field observation. 

Aerial observation. 

Media reports. 

Portable traffic management systems.

Information systems 

Incident reports. 

Construction activities. 

Special event schedules.

Shared resources represent one of the potential major benefits of coordinated operations, 

especially during major construction projects. Through shared resources, the collaborating 

agencies can make available more information then they can individually provide. Since a major 

work zone is often has substantial spillover effect, shared resources are a win-win proposition. 

4.4.6 Evaluation and Selection of Strategies 

The process of selecting the specific strategies is an iterative process involving the partners in 

assessing both the costs and the benefits of the strategies and the various agencies ability to 

implement the strategies. A strategy may be perceived to be positive, but a more detailed 

analysis may show it to be counterproductive. A strategy may be technically feasible, but not 

selected because it is beyond the resources available, or possibly inconsistent with community 

values. 

The following factors can be used to evaluate potential traveler information, traffic management 

and control, and shared information and resource strategies that can be used to be coordinate 

freeway/arterial roadways during work zone operations: 

 Duration of the operation. 

 Capacity impacts. 

 Volume of traffic affected. 

 Funding. 

 Existence of traffic generators. 

 ITS deployment that is available (existing or to be installed). 

There are some analytic tools that can determine the impact of work zone operations on a 

roadway and therefore provide some indication on the volume of traffic that might need to be 

diverted to alternate routes or shifted to alternate modes. An example is QuickZone. Information 

on QuickZone can be found at: http://www.tfhrc.gov/its/quickzon.htm. 
81

QuickZone is the first tool developed under the Strategic Work Zone Analysis Tools program. 

These tools are intended to be user-friendly software tools that assist those in the highway 

community with decisionmaking. QuickZone is a traffic impact analysis spreadsheet tool that 

can be used for work zone delay estimation. The purpose of QuickZone is to: 

 Quantify corridor delays resulting from capacity decreases in work zones. 

 Identify delay impacts of alternative project phasing plans. 

 Support tradeoff analyses between construction costs and delay costs. 

 Examine impacts of construction staging by location along mainline, time-of-day (peak versus 

off-peak), and season (summer versus winter). 

 Assess travel demand measures and other delay mitigation strategies. 

 Support development of work completion incentives. 

At this point in the process, there is a clear overlap between incident management and work zone 

operations response planning. There are similar, important review items to be considered prior to 

diverting traffic from a freeway to a surface street, including whether or not there are permit or 

utility operations that have been deployed without prior notice; the presence of schools, 

hospitals, or shopping centers on the alternate route; and the presence of major employment 

centers on the diversion route. Additional considerations include the question of whether 

temporary turning or parking restrictions are needed. If so, the question then arises as to whether 

it is possible to deploy manual resources to erect appropriate signing and/or implement such 

changes safely and in a timely manner. Additional discussion of strategy evaluation and selection 

considerations can be found in section 3.8. 

While each jurisdiction may have individual characteristics, and it is preferable to have 

preplanned diversion routes, the following are some possible items to review before diverting 

traffic from a surface street to a freeway: 

 Is the surface street connected to the freeway (preferably at both ends of the diversion) or are 

there multiple streets involved in the diversion route? Is trailblazing along the diversion route 

necessary, and if so, is it in place? 

 Is there other roadwork in place along the diversion route? 

 Are there any special events along the diversion route that may hinder traffic? 

 Are there other unusual circumstances along the diversion route (i.e., shopping mall during 

holiday season, school day ending)? 

In planning the operations strategies to be used during work zones, there are questions which 

should be considered: 

What is the cost of various coordination efforts? 

Most actions, beyond notifications, carry some cost to the agencies responsible for carrying them 

out. For example, if a city must deploy police officers to manually direct traffic at diversion 

points or through intersections, there is a significant cost to supply that labor. Issues of who pays 

for what should be agreed to ahead of time. 
82

What resources are available? 

Knowing ahead of time what resources can be used allows the agencies to coordinate their 

efforts more effectively and to determine what level of response is appropriate. Permanent DMSs 

can be easily adjusted with messages displayed even for work zones of short duration. On the 

other hand, if portable signs need to be deployed, agency personnel must consider whether the 

time and effort to retrieve the signs, transport them to the location, and program messages is 

worth the effort given the expected duration of the work zone. 

Upon completion of this step, all stakeholders should have a detailed understanding of what 

strategies are feasible and supported by the corridor agencies. The next step is to package all of 

the strategies in a corridor plan, which is the formal document, which can be used to secure the 

funding necessary to advance the program to design. 

4.4.7 Corridor Implementation Plan 

The corridor implementation plan is the final product of the decisionmaking component of the 

CFA operations framework. It documents all the steps previously undertaken with sufficient 

detail to take the project or projects developed for improved corridor operations to the 

implementation stage. 

The corridor implementation plan is the second major product after the concept of operations. It 

contains sufficient detail to move to the design step and may contain a number of projects, 

especially if it is necessary to fund and construct the implementation over a long timeframe. The 

plan should also indicate priorities among projects, potential funding sources, and cost 

allocation. 

A detailed discussion of the elements of the corridor implementation plan and a list of the issues 

and resources that need to be addressed during its development are in section 3.9 above. 

4.4.8 Design and Development 

Design and development is the first step in the implementation section of the framework. This is 

a significant step forward in that it transforms the corridor implementation plan concepts into 

projects that are able to be implemented. It covers many details of implementation including the 

necessary construction plans to build the supporting infrastructure and specifies detailed 

procedures and supporting agreements necessary to operate and maintain the operations plans. A 

detailed discussion of important elements of the design phase can be found in section 3.10 above. 

The implementation of the design and development phase can be either separate from the work 

zone contractual package or incorporated as an early phase. Regardless, the important 

consideration in either case is the required leadtime to implement the strategies prior to the start 

of the work zone operations. In some states, design/build procurements are used to consolidate 

this step and deployment, the next step. The selection of technologies addresses the way the 

varying phases of construction will impact the use of ITS technologies. 

Strategies may also vary by time of day, reflecting both the volume of traffic on the freeway and 

the conditions on adjacent arterials. Table 9 is an example of a corridor operations plan with 

activation criteria based on freeway capacity loss, duration of work zone, and the time of day. In 
83

this freeway example, letters represent the level of response, which are recommended based on 

three factors: the time of day the incident occurs, the expected duration of the incident, and the 

amount of capacity lost on the roadway experiencing the incident. The example shown is fairly 

complex and could be simplified based on reducing the number of time periods and the number 

of categories of duration. 

Table 9. Example corridor operations plan for freeway work zone. 

Freeway Capacity Loss 

Time of Day Duration Low Medium High 

All Day 24 hours (h)/day N, T, A, M, D1 N, T, A, D1 N, T, A, M, D2 

Weekday Daytime 

Off-peak 

0–20 minutes (min)

20 min–2 h 

2–4 h 

> 4 h 

N

N, T, A 

N, T, A, D1 

N, T, A, D1 

N, T 

N, T, A 

N, T, A 

N, T, A, D1 

N, T, A 

N, T, A, D1 

N, T, A, M, D2 

N, T, A, M, D2 

Weekday 

Nighttime 

Off-peak 

0–20 min 

20 min–2 h 

2–4 h 

> 4 h 

N

N, T 

N, T 

N, T 

N, T 

N, T, A 

N, T, A 

N, T, A 

N, T 

N, T, A, D1 

N, T, A, D2 

N, T, A, D2 

Weekend Daytime 

0–20 min 

20 min–2 h 

2–4 h 

> 4 h 

N

N, T, A 

N, T, A, D1 

N, T, A, D1 

N, T 

N, T, A 

N, T, A 

N, T, A, D1 

N, T, A 

N, T, A, D1 

N, T, A, M, D2 

N, T, A, M, D2 

Weekend 

Nighttime 

0–20 min 

20 min–2 h 

2–4 h 

> 4 h 

N

N, T 

N, T 

N, T 

N, T 

N, T, A 

N, T, A 

N, T, A, D1 

N, T 

N, T, A, D1 

N, T, A, D2 

N, T, A, D2 

N = notification is made to affected agencies. 

T = traveler information is provided via resources such as DMS, HAR and media. 

A = motorists are advised to use an alternate route. 

D1 = motorists are advised to use a particular alternate route. 

D2 = motorists are forced onto an alternate route. 

Notes: ·It is assumed that different governmental entities operate the surface street and freeway systems. ·A 

decisionmaking matrix is needed when a diversion to an alternate route is warranted that requires confirmation of 

available capacity and/or the absence of a planned or unplanned event on that route. · Traveler information 

systems can be portable or permanent DMSs, HAR, kiosks or Internet-based systems and also include 

media/traffic service notifications. 

While strategies are funded and developed with the specific work zone operation in mind, where 

possible there should be some consideration to the continued use of these strategies beyond the 

work zone operation. 

4.4.9 Deployment 

The deployment phase includes activities in preparation for implementation and the various steps 

necessary to implement the system designed in the previous step. A full discussion of the 

considerations required for implementation can be found in section 3.11. 
84

4.4.10 Operations and Maintenance 

Operations and maintenance is often overlooked with serious negative consequences. Within an 

agency, someone must be responsible for coordinating the operations and maintenance of any 

mitigation strategies. Where possible, the champion should encourage incorporating this activity 

into an existing TMC or operation. Other considerations in the operation and maintenance of 

work zone mitigation strategies are as follows: 

 Work zone operations are dynamic activities and there must be changes to the work zone 

sequencing because of unforeseen issues. For a daily pothole repair work zone operation, the 

trucking firm that is delivering asphalt to the site may have been delayed and arrive late to the 

site. Unforeseen situations such as this can extend the duration of the work zone operation. 

 The potential for incidents within work zones is significant. A quick response to incidents, 

even minor ones, will reduce motorist delay and help avoid secondary incidents that can be 

worse than the primary one. In addition, access to emergency services must be coordinated. 

 For long-term work zone operations, there should be frequent meetings with the different 

stakeholders to inform them of the status of the work zone operation, gauge how well the 

strategies are working, and make any necessary changes. 

 Other events that impact the work zone operation include special events within the corridor 

impacted by the work zone operation, work zone or permit operations on the alternate routes, 

or incidents that take place along the alternate routes. The development and implementation of 

an information sharing system will help communicate and coordinate interagency responses.

4.4.11 Continuous Improvement 

Continuous improvement should be well integrated into the overall process. As stated in previous 

sections, the performance monitoring system should provide feedback on both the success of 

individual operations plans and the need for other actions. In addition, regular stakeholders 

meetings are an advantageous means of facilitating ongoing communications and exchanging 

stakeholder experiences with coordinated operations to refine existing operations. 

The National Work Zone Safety Information Clearinghouse (http://wzsafety.tamu.edu/) is a 

reference tool on policies, practices and technologies that have been effectively used to manage 

work zone operations. This site is updated regularly and is an ongoing source of information. 

4.5 Planned Special Events Management 

A planned special event is a public activity or series of activities with a scheduled time and 

location that may increase or disrupt the normal flow of traffic on affected streets or highways. 

As with work zones or traffic incidents, special events may also have a ripple effect on 

transportation within a corridor for many reasons. The unsuspecting traveler may encounter 

unexpected delays, and when alternative routes are not clearly conveyed to travelers, congestion 

and incidents are more likely to occur. The purpose of this section is to apply the CFA 

framework to planned special event management in a corridor. The benefits of taking a 
85

corridorwide view of special event coordination include maximizing system performance and 

effectively minimizing the overall effect of the special event on the transportation system within 

that corridor. At the conclusion of this section, readers will have an understanding of how to 

expand their approach to special event coordination from a single, local project focus to a 

corridorwide management perspective. 

The impacts of special events may not always be restricted to the immediate event venue. The 

impacts may be felt on other roadway corridors, within the regional transportation network, or on 

other modes of transportation. 

Expanding the special event coordination processes to corridors is the goal of CFA operations. 

While there is no single solution for development of special event coordination, the key to 

success is the expansion of the scope of special event coordination from a venue focus to a 

corridor management view. Special event coordination takes a corridor view that focuses on 

maximum system performance from the users’ perspective by minimizing the overall effects of 

the special event. 

The guidance from Managing Travel for Planned Special Events provides many of the details for 

developing special event plans and procedures.(25)Figure 17 shows the recommended process for 

managing special events in Managing Travel for Planned Special Events. Many of the steps in 

figure 17 are similar to the 11-step CFA process detailed in this handbook. These similarities will 

be highlighted in the remainder of this section. Event operations planning, shown in figure 17, is 

similar to steps 1 (problem identification) through 6 (evaluation and selection of strategies) of the 

CFA process. Event operations planning involves developing: a feasibility study for the proposed 

planned special event; a traffic management plan to service event-generated auto, transit, and 

pedestrian traffic and to mitigate transportation impacts; and a travel demand management plan 

when forecasted traffic demand levels approach or exceed available roadway capacity. 

Training and implementation, as shown in figure 17, is similar to the corridor implementation 

plan and design and development steps of the CFA process. Training and implementation starts 

with the development of an implementation plan ranging from a brief memorandum, and 

concludes with an event management manual. Stakeholders representing the event planning and 

traffic management teams interact through event simulation exercises that may consist of a 

tabletop exercise, an event walk-through, or a traffic management plan deployment during a 

smaller-scale event. These exercises assist participants in identifying potential traffic 

management plan deficiencies and, in addition, will allow traffic management team members to 

become familiar with decision criteria and contingency plan details. 
86

Figure 17. Chart. Integration of planned special event management phases.(25)

Day-of-event activities, as shown in figure 17, are similar to the operations and maintenance step 

of the CFA process. Day-of-event activities focus on the implementation of the traffic 

management plan in addition to traffic monitoring. The traffic management team represents a 

distinct stakeholder group charged with executing the traffic management plan. Traffic 

monitoring provides traffic and incident management support in addition to performance 

evaluation data. Timely deployment of contingency plans developed during the event operations 

planning phase depends on the accurate collection and communication of real-time traffic data 

between traffic management team members. 

Post-event activities, as shown in figure 17, are similar to the continuous improvement step of 

the CFA process. Post-event activities range from informal debriefings between agencies 

comprising the traffic management team to the development of a detailed evaluation report. 

Qualitative evaluation techniques include individual debriefings of traffic management team 

members, patron surveys, and public surveys. Quantitative evaluation techniques include 

performing an operational cost analysis and analyzing traffic data collected during the traffic 

monitoring process. 
87

4.5.1 Problem Identification 

Planned special events include sporting events, concerts, festivals, and conventions occurring at 

permanent multi-use venues (e.g., arenas, stadiums, racetracks, fairgrounds, amphitheaters, 

convention centers, etc.). They also include less frequent public events such as parades, 

fireworks displays, bicycle races, sporting games, motorcycle rallies, seasonal festivals, and 

milestone celebrations at temporary venues. The term “planned special event” is used to describe 

these activities because of their known locations, scheduled times of occurrence, and associated 

operating characteristics. Emergencies, such as a severe weather event or other major 

catastrophe, represent special events that can induce extreme traffic demand under an evacuation 

condition. However, these events occur at random and with little or no advance warning, thus 

differing from planned special events. 

Substantial technical material exists in the FHWA technical reference Managing Travel for 

Planned Special Events.

(25) It presents and recommends various planning initiatives, operations 

strategies, and technology applications that satisfy the special customer requirements and 

stakeholder performance requirements driving planned special event travel management. This 

section summarizes that reference, highlighting the essential elements involved in managing 

traffic during planned special events. In addition, opportunities for CFA operations will be 

highlighted. 

4.5.2 Institutional Considerations 

Because of the high visibility of such events, agencies naturally come together. In addition, 

because of their unique nature, day-to-day plans and procedures are, by definition, not 

applicable. The short duration of special events may also make agencies more willing to commit 

resources because it does not represent an ongoing commitment. 

An appropriate institutional structure needs to be developed to sustain the effort. The type of 

structure will depend on the local circumstances and should build, if possible, on existing 

relationships, but the basic principles of developing institutional relationships remain the same: 

establish a structure, identify corridor stakeholders, and identify corridor champions. 

Figure 18 presents common stakeholders, representing various disciplines and jurisdictions that 

play an active role in managing travel for planned special events on a local and/or regional level. 

The balance of this section describes the potential roles and responsibilities of each identified 

stakeholder in addition to his or her coordination with other planned special events stakeholders. 
88

Law Enforcement

State Police

County Police/Sheriff

Local Police

Transportation Agencies

State DOT

County/Local DPW

Planning Department

Transit Agencies

Media

Television/Radio

Traffic Advisory Service

Fire and EMS Event Organizer

Special Event

Stakeholders

Private Industry

Transportation Consultants

Traffic Control Vendors

ITS Vendors

Regional Coalitions

Metropolitan Planning Organizations

Regional Operating Organizations

Government Agencies

Office on Special Events

Department of Permits

Emergency Management Agency

Public

Businesses

Residents

Elected Officials

Mayor or City/Village Manager

City/Village Alderperson

Figure 18. Chart. Stakeholders who may be involved in planned special events. (25)

Law enforcement facilitates the safe and efficient flow of traffic during a planned special event 

through traffic control and enforcement. Agencies contribute to all phases of planned special 

events, particularly event-specific advance planning and traffic management. Local and county 

law enforcement having a traffic operations bureau may take responsibility for developing and 

executing a surface street traffic management plan. Other potential duties of law enforcement 

include approving local street closures, approving an event traffic flow plan, approving 

temporary traffic control deployment, escorting dignitaries to/from the event venue, and 

enforcing the requirements of a traffic operations agency. 

Event organizers initiate the event operations planning phase by notifying stakeholders, through 

a written request to public agencies or the submission of an event permit application, and 

assembling an event planning team. The event organizer continually works to maintain 

interagency coordination to meet milestones in the advance planning process and ultimately gain 

stakeholder approval of the proposed transportation management plan. The event organizer may 

hire a private traffic engineering consultant to perform an event feasibility study and prepare a 

traffic management plan. The event organizer usually funds the deployment of equipment and 

personnel resources, including reimbursement of public agency personnel costs required to 

mitigate traffic safety, mobility, and reliability impacts during the day-of-event. However, event 

organizers for major special events that occur on a regular basis may work together with 

transportation agencies, law enforcement, and elected officials during the strategic planning 

phase to develop strategies, including permanent installation of equipment for improved traffic 

monitoring and control and to better accommodate traffic and transit access to the venue. 

Elected officials serve the overall community interest and often have a significant role on an 

administrative team. Local politicians can establish laws and regulations toward effecting 

improvements in planning and managing future planned special events. A local mayor or 

manager may create a special task group to assist event organizers and local agencies coordinate 

event-planning activities. Local district politicians may advise an event planning team on 
89

alternatives to minimize quality of life impacts on residents and businesses represented by the 

elected official. 

Fire and emergency medical services (EMS) advise the event planning team on the provision 

of emergency access routes to and from the event venue. 

The media functions to disseminate pretrip event and associated travel information, in addition 

to real-time information on traffic and transit conditions during the day-of-event to assist event 

patrons and other road users. A media representative may participate in a meeting of the event 

planning team to obtain advance information on proposed temporary traffic control, transit, and 

travel demand management initiatives. However, the media generally works independently of the 

traffic management team on the day-of-event. 

Private industry satisfies a wide range of public agency needs from the event operations 

planning phase through the day-of-event activities phase. Traffic engineering consultants may 

assume the role of a public agency traffic engineer and in turn, develop a transportation 

management plan and manage either an event planning team, traffic management team, or both. 

Private traffic control vendors, such as barricade companies, fulfill the duties of a transportation 

agency maintenance department. ITS equipment vendors contract with transportation agencies 

to: 1) install permanent equipment such as CCTV cameras, lane control signals, dynamic 

trailblazers, and parking management systems on surface streets serving a fixed event venue or 

2) deploy portable traffic management systems, including portable CCTV, portable changeable 

message signs, portable HAR, portable vehicle detectors, and portable traffic signals. In some 

instances, transportation agencies may arrange for an equipment demonstration, at no cost to the 

agency, to evaluate the performance of a particular technology application during a planned 

special event. 

Regional coalitions interact with both the administrative team and an event planning team 

regarding major planned special events affecting a regional area. A metropolitan planning 

organization (MPO) oversees the planning and programming of transportation management 

strategies. For example, the agency may communicate and seek feedback on temporary travel 

demand management strategies with commuter groups and trucking companies. An MPO may 

loan staff to other public agencies in need of personnel to conduct planning and operations 

activities. The agency may also establish and/or coordinate temporary task forces charged with a 

particular function, such as event communications. A ROO, as explained earlier in section 2.3, 

consists of traffic operations agencies, transit agencies, law enforcement, elected officials, and 

other operations agencies focused on the operation and performance of a regional transportation 

system. 

Government agencies denote nontransportation agencies that generally serve in an 

administrative capacity. A government office responsible for special events may work in tandem 

with the event organizer to initiate the event operations planning phase and coordinate event 

planning team stakeholders. Other governmental emergency management and security agencies 

may meet with the event planning team to obtain an advance debrief on transportation 

management plan specifics. 
90

The public represents individual residents, businesses, and associated community groups. 

Residents and businesses potentially impacted by intense traffic and parking demand generated 

by a planned special event may interact with event planning team stakeholders during a public 

meeting. This permits concerned citizens the opportunity to review and discuss proposed traffic 

and parking restrictions needed to accommodate event traffic. 

In summary, the complexity of special events requires a much larger group of stakeholders than 

other corridor management applications. To achieve corridor level operations, it is necessary to 

take special event management to a broader level of involvement, which expands the number of 

stakeholders involved. The large number of stakeholders may require the development of a more 

multifaceted organization structure to effectively deal with the complexity cause by number of 

issues and the number of agencies involved. 

4.5.3 Goals, Objectives, and Performance Measures 

The goals, objectives and performance measures of planned special event coordination should be 

established before working on the strategies to improve corridor operations. This allows the 

partners to define broadly what they are willing to do, before defining where and how they will 

do it. By starting with goals, the partners can define what aspects of corridor special event 

coordination they believe they can undertake. This is an important step because not all parties 

may see the goals for special event coordination the same way. It is easier to understand conflicts 

at the goal level because they are general in nature. 

The potential impact of a planned special event is often difficult to predict and measure. 

However, establishing goals provides the necessary focus to understand what is potentially 

achievable through corridor coordination. Some candidate goals from Managing Travel for 

Planned Special Events include:(25)

 Achieving predictability. 

 Ensuring safety. 

 Maximizing efficiency. 

Specific objectives include: 

 Reducing delay. 

 Reducing incidents. 

 Reducing non-event traffic demand. 

4.5.4 Corridor Concept of Operations 

The corridor concept of operations is a formal document that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed in part to help communicate this view to 

the other stakeholders and to solicit their feedback. In essence, the corridor concept of operations 

provides a description of the current system, operating practices and policies, and existing 

capabilities. It lays out the program concept, explains how the corridor system is expected to 

work once it is in operation, and identifies the responsibilities of the various stakeholders for 

making this happen. The goals, objectives, and performance measures of a proposed operation 

are also documented. The process of developing a concept of operations for a corridor should 

involve all stakeholders and serve to build consensus in defining the goals and objectives; to 
91

provide an initial, definitive expression of how functions are performed, thereby supporting 

resource planning; and to identify the interactions between organizations. 

The planned special events management concept of operations is the document that creates the 

high-level understanding of the planned special event management program. The concept of 

operations represents the initial support for the program and records the agreed upon approaches 

to be pursued in more depth. 

The basis of the planned special events management concept of operations is the development of 

high-level problematic issues that warrant corridor-level special event response. The issues are 

presented as scenarios developed from problems identified in the first step in the framework. 

Problems whose alleviation is consistent with the corridor goals and objectives would be 

candidates for mitigation developed into high-level issue statements. 

Problematic issue statements represent the initiating event for mitigation of the effects of special 

events. At the concept of operations stage, issues are broad: they do not focus on specific 

strategies. An example of this level of strategy could be to facilitate access to a special event 

venue by providing improved traffic management involving traveler information and revised 

traffic signal control on the major access routes. 

At this stage, the cooperating agencies answer the questions of what (not how) they would be 

willing to do in the corridor to coordinate operations in response during a special event. General 

strategies could include: 

 Traveler information. 

 Traffic management and control. 

 Shared information and resources. 

The general strategy might be to use existing freeway DMSs to alert freeway drivers to the event 

so they might avoid the venue and seek an alternative route. Another high-level strategy might be 

to provide special arterial signal timing at the freeway exit to reduce freeway congestion. 

The development of a concept of operations allows participating agencies to agree on what they 

wish to accomplish and to lay the framework for how that will be done. For example, does the 

traveler information only describe the nature of the problem or does it provide recommended 

courses of action? This is an example of an issue the agencies should resolve before moving to 

the more detailed level of discussion. 

As part of the development of a concept of operations, consider the following points: 

 Does stakeholder consensus exist to develop corridor-based special event coordination? If not, 

does it exist for other types of situations such as work zones or major construction and 

maintenance operations? If so, could success in the other situations be built upon to develop 

special event coordination within the region? 

 If stakeholder consensus must be established, who will be the champion and organize a 

workshop or forum to demonstrate the benefits? 

 What is the level of stakeholder commitment of personnel and funding resources? 
92

 What policy changes, if any, are needed to implement special event coordination (such as 

interagency MOUs)? 

 What organizational structure will be established to enable the many agencies to work 

together effectively? 

The concept of operations document often includes the following sections: 

 Summary of the overall goals of special event coordination. 

 Description of the corridor and the stakeholders. 

 Description of the high-level problematic issues. 

 Description of types of strategies to be implemented. 

 Identification of roles and responsibilities of stakeholders. 

 Identification of policies and procedures that require modification. 

 Estimate of costs. 

 Identification of schedule for planning, development and implementation. 

In summary, the concept of operations defines the high-level problematic issues that will be used 

to address the defined problems consistent with the corridor goals and objectives. The detailed 

issues and strategies have to be worked out in the development of the corridor implementation 

plan. The concept of operations phase of planning involves the who, what, when and where of 

special event coordination. The corridor implementation plan will determine how it will be done. 

4.5.5 Corridor Scenarios and Operations Strategies 

The main objective of CFA operations during planned special events is to maximize system 

effectiveness. Traveler information can mitigate demand, influence mode choice, influence route 

selection, and otherwise improve traveler reaction to negative impacts of the event. Better 

coordinated control systems increases throughput and minimizes impacts on motorists not 

attending the special event, but traveling on the roadways in the area. 

Table 10 lists example strategies for mitigating the impacts of planned special events on local 

roadway and regional transportation system operations. In meeting the overall travel 

management goal of achieving efficiency, these strategies target the excess capacity of the 

roadway system, parking facilities, and transit. Through travel demand management, event 

planning team stakeholders develop attractive incentives and use innovative communication 

mechanisms to influence event patron decisionmaking and ultimately traffic demand. 
93

Table 10. Example strategies for mitigating special event congestion. 

Category Example Strategies 

Traffic Management and Control 

Freeway management 

Ramp closures. 

Elimination of weaving areas. 

Ramp metering timing and coordination. 

Arterial management 

Access and turn restrictions. 

Advance signing to improve traffic circulation. 

Traffic signal timing and coordination. 

Lane control use adjustments. 

Road closures. 

Onstreet parking restrictions. 

Trailblazer signing. 

HOV incentives 

Public transit service expansion. 

Express buses from park and ride lots. 

Charter bus service. 

Preferred parking. 

Reduced parking cost. 

Traveler Information 

En route traveler information

DMSs (temporary and permanent). 

Trailblazer signing. 

Pagers, PDAs. 

CB radios. 

Cell phone/511. 

HAR. 

Media. 

Local travel demand management Background traffic diversion. 

Truck diversion. 

Pretrip traveler information 

Internet. 

Telephone information systems. 

Public information campaign. 

Event and venue transportation guide. 

Media. 
94

Table 10. Example strategies for mitigating special event congestion (continued). 

Category Example Strategies 

Shared Information and Resources 

Incident response 

Motorist service patrols. 

Wreckers. 

Portable DMS. 

Traffic surveillance 

CCTV systems. 

Field observation. 

Aerial observation. 

Media reports. 

Portable traffic management systems. 

Information systems 

Incident reports. 

Construction activities. 

Special event schedules. 

Special Events Management 

Event patron incentives Pre-event and postevent activities. 

Bicyclist accommodation Bicycle routes and available parking/lock-up. 

Shared resources represent one of the potential major benefits of coordinated operations during 

special events. Through sharing resources, collaborating agencies can make available more 

information than they might individually provide. Since a major special event is likely to have a 

substantial spillover effect, shared resources are a win-win proposition. 

4.5.6 Evaluation and Selection of Strategies 

As discussed previously, the process of selecting the specific strategies is an iterative process 

involving assessment of the costs and the benefits of the various strategies as well as the 

stakeholder agencies’ ability to implement the strategies. Each of the participating agencies must 

be comfortable with the strategies and be capable of implementing them. 

The candidate lists of strategies must be evaluated from an institutional and financial basis. The 

following factors can be used to evaluate potential traveler information, traffic management and 

control, and shared information and resource strategies that can be used to be coordinate 

freeway/arterial roadways during special events: 

 The time of the event. 

 The duration of the event. 

 Volume of traffic affected. 

 Funding. 

 ITS deployment that is available (existing or to be installed). 

The strategies may also vary by time of day, reflecting both the volume of traffic on the freeway 

and the conditions on adjacent arterials. 
95

Upon completion of this step of the process, a detailed understanding of what strategies are 

feasible and supported by the corridor agencies should be shared by all stakeholders. The next 

step is to package all of the strategies into a formal corridor implementation plan. 

4.5.7 Corridor Implementation Plan 

The corridor implementation plan is a product of the decisionmaking component of the CFA 

framework. It documents all the steps previously undertaken with sufficient detail to take the 

project or projects developed for improved corridor operations through to the implementation 

phase. 

A full discussion of development and contents of a corridor implementation plan can be found in 

section 3.9 above. 

4.5.8 Design and Development 

The design effort is the first step of the implementation phase of the framework. It is vital 

because it transforms the corridor implementation plan concepts into projects that are able to 

implemented. The phrase “design and development” comprises many details of implementation 

including, if necessary, construction plans to build supporting infrastructure and the detailed 

procedures and agreements necessary to operate and maintain the operations plans. 

The issues addressed in the design phase include performance requirements, functional 

requirements (what is trying to be accomplished), system architecture (how does the system 

work), identification and screening of technologies, and specification of technologies. All of 

these issues are addressed fully in section 3.10, and chapter 5 discusses the types of ITS 

technologies that can be used in CFA management in greater depth. 

Table 11 presents an example checklist for elements to include in a corridor operations plan. 
96

Table 11. Special event operations plan checklist. 

Element Provision 

Freeway control 

plan 

Specify maintenance and protection of traffic per the Manual on 

Uniform Traffic Control Devices (MUTCD) guidelines (e.g., location 

of traffic control equipment, equipment quantities, and safety signs). 

Indicate ramp control and capacity modifications. 

Highlight exclusive traffic flows (e.g., unimpeded merge, etc.). 

Dimension weaving area, acceleration/deceleration lane lengths, ramp 

length. 

Indicate potential bottleneck locations for surveillance monitoring. 

Street control 

plan 

Show closed road segments. 

Indicate directional lane control (e.g., alternative lane operations). 

Show one-way streets. 

Indicate number of ingress and egress lanes at each venue access point 

(e.g., parking areas, pickup/dropoff points). 

Show street use event route. 

Indicate parking restrictions. 

Indicate location of command post(s). 

Integrate with signing plan (e.g., show route trailblazer signs). 

Intersection 

control plan 

Specify maintenance and protection of traffic per MUTCD guidelines 

(e.g., location of traffic control equipment, equipment quantities, and 

safety signs). 

Show permitted pedestrian movements and crosswalk locations. 

Indicate approach lane designations and pavement markings. 

Indicate traffic control. 

Highlight exclusive/permitted traffic flows (indicate approach lane and 

corresponding receiving lane). 

State special regulations (e.g., turn prohibition, exclusive bus lane, 

resident/permit only movement). 

Show approach closures. 

Indicate parking restrictions. 

Indicate location of traffic control officers. 

Indicate location of equipment storage area at intersection. 
97

Table 11. Special events operations plan checklist (continued).

Element Provision 

Signing plan Show location of permanent/portable changeable message signs. 

Show location of permanent/portable HAR stations. 

Indicate CMS/HAR message sets. 

Default ingress and egress. 

Contingency scenarios. 

Show location of temporary static signs and message. 

Indicate location of dynamic blank-out signs. 

Equipment 

location plan 

State number of traffic cones, drums, and barricades required at 

designated locations. 

Indicate equipment staging areas (e.g., shoulder, median, 

intersection corner). 

Indicate location of equipment storage areas. 

Other 

considerations 

Provide plans for both ingress and egress operation. 

Indicate roadway construction zones. 

Include table of quantities. 

Show aerial map. 

Draw map to scale. 

Display landmarks. 

Source: Managing Travel for Planned Special Events(25)

While strategies are funded and developed with the specific special event in mind, where 

possible, there should be some consideration given to the possibility of overlap, whereby the 

same strategies can be applied to applications such as incidents or work zone activities. 

4.5.9 Deployment 

The deployment phase includes all activities preparatory to deployment and the various activities 

necessary to execute the system as per the design. 

The implementation process may involve both people and infrastructure. New staff may need to 

be hired and trained. As the complexity of the project increases, phasing and timing of the range 

of elements needs careful consideration so that the system components can be deployed and 

tested in a timely fashion. More information on this step is contained in section 3.11. 

4.5.10 Operations and Maintenance 

Because of their short duration, special events typically have fewer issues with operations and 

maintenance unless the event is recurring within an agency, in which case there needs to be 

someone responsible for coordination of the operations and maintenance of any strategies. 

Special events are dynamic activities and often require adjustments to plans due to unforeseen 

events. Such unplanned occurrences may extend the duration of the special event, which will 

require adjustments in staff resources. 
98

The potential for incidents during special events is significant. A quick response to incidents, 

even minor ones, will reduce motorist delay and help avoid secondary incidents. In addition, 

swift access to emergency services must be coordinated. 

4.5.11 Continuous Improvement 

Continuous improvement is a part of the overall process of the CFA Framework. The frequency 

of special events will influence the degree to which continuous improvement is effective. Ideally, 

the performance monitoring system provides desirable feedback on both the success of 

individual operations plans and the potential to improve future activities. Stakeholder meetings 

can be advantageous as a means of facilitating ongoing communications. At these meetings, 

stakeholders should discuss experiences with coordinated operations to refine existing 

operations. 

4.6 Day-To-Day or Recurring Operations 

Day-to-day or recurring operations generally refer to managing repeated congestion that occurs 

due to peak period volumes exceeding the available capacity of the roadway(s), creating 

recurring bottlenecks. The purpose of this section is to apply the CFA framework to day-to-day 

operations coordination in a corridor. The benefits of taking a corridorwide view of daily 

operations coordination include maximizing system performance and effectively minimizing the 

overall effect of congestion-causing factors on the transportation system within that corridor. The 

section will discuss identification of the types of day-to-day challenges encountered in a corridor 

and how to determine goals and strategies for dealing with them effectively. Upon completion of 

this section, the reader should have a good grasp of the factors involved in coordinating day-today operations within a corridor. 

Coordination of day-to-day operations within a corridor to alleviate congestion involves an 

expanded view of operations that transcends jurisdictional boundaries or, in some cases, internal 

agency structures that commonly separate freeway operations from arterial operations. In many 

States, multiple agencies operate freeways and arterials. State DOTs typically own and maintain 

the freeway system, and city or county agencies are responsible for arterials. Through 

coordinated actions, the operation of these separate systems can be made more effective from a 

user perspective. 

Many practices for managing day-to-day operations are well established and have been 

addressed in other documents such as the Freeway Management and Operations Handbook.

(20)

Some practices, such as coordinating the operation of ramp meters and nearby traffic signals, are 

still in the early stages of development. 

The CFA framework provides the organizational structure for this section, and the following 

sections reflect the 11-step framework for developing the desired coordinated operations. 
99

4.6.1 Problem Identification 

The problem definition for recurring congestion is an issue of identifying bottlenecks and 

congestion hot spots. The following factors help define the day-to-day problems that should be 

addressed: 

 Signalized arterials crossing jurisdictional boundaries. 

 Interchanges with ramp meters and traffic signals that are not coordinated. 

 Freeway and arterial traveler information systems that are not coordinated. 

 Available resources that are not accessible to other agencies. 

While day-to-day problems are typified by organizational seams, such as the separate groups 

responsible for arterial and freeway operations, there are also day-to-day problems caused by 

equipment malfunctions or fluctuations in traffic that have systemic effects beyond the 

immediate location of the problem. 

In assessing current day-to-day practices from a corridor perspective, the following questions 

may help identify problems that are amenable to coordinated corridor management: 

 Do agencies share information on operational problems? 

 Are signals coordinated across agency boundaries? 

 Are ramp meters and traffic signals coordinated? 

 Are agency’s practices such as Web-based traveler information redundant? Can coordinated 

operations free up resources? 

 Are there opportunities for shared resources to improve operations? 

4.6.2 Institutional Considerations 

Day-to-day management involves multiple agencies and disciplines and therefore requires an 

appropriate structure with a clear delineation of roles and responsibilities to sustain the effort. 

The type of structure depends on the local circumstances and builds from existing relationships, 

if possible. 

To advance a large project, such as a shared traffic management/operations center, from 

inception through implementation may require the organization of executive, steering, and 

operation committees that will need to be informed throughout the various stages of the project. 

The key stakeholders that need to be involved in day-to-day operations fall into the following 

categories: 

 State and local political leadership. 

 Intra-agency personnel such as planning, design construction engineering, and public 

information staff. 

 Interagency such as law enforcement and emergency management agencies, local public 

works and transit agencies. 

 Managers of special event venues. 

 Major employers and/or traffic generators. 

 Media. 
100

To mobilize these individuals and agencies into an effective CFA operations daily management 

program, a concerted effort is required to bring these individuals together in new ways. To 

achieve the desired outcomes, it is necessary to consider the legal and policy environment in 

which coordinated day-to-day management is carried out. Questions that may be helpful in 

determining this environment include:(19)

 What are the legal limits to day-to-day management that agency personnel can perform? (e.g., 

can one agency operate another agency’s devices?) 

 To what extent do real or perceived legal constrictions pose an obstacle to coordinated day-today management? 

 What is the financial liability of agencies, agency personnel, and the public with respect to 

coordinated day-to-day operations management? 

 Can or should statutes be changed to facilitate coordinated day-to-day management? 

As part of the coalition building process, if a project to coordinate freeway arterial operations is 

going to succeed, champions must emerge or be identified. The champions are needed to guide 

the project from inception to completion and help navigate through the institutional challenges. 

In summary, this step of the process involves expanding the area of day-to-day operations 

management from an agency focus to a corridor focus. It takes operations management to the 

next level, a corridor management program, by either broadening existing relationships or 

establishing new institutional relationships. 

4.6.3 Goals, Objectives, and Performance Measures 

To gain consensus from stakeholders, goals, objectives and performance measures should be 

established for the plan that will be developed and implemented to provide better day-to-day 

coordination of freeways and arterials. Traffic management strategies need to address the 

following major goals: 

 Improve traveler safety. 

 Minimize traveler congestion. 

 Improve travel reliability. 

Once the goals have been established, specific objectives can be defined to reflect the various 

perspectives of participants. Table 12 is an example of specific objectives. 
101

Table 12. Example objectives for day-to-day operations. 

Goal Objectives 

Improve traveler safety Reduce crash rates by X percent. 

Minimize traveler congestion Travel delay no greater than X percent. 

Alternative routes to not exceed design capacity. 

Improve travel reliability Maximum travel times through primary freeway corridor to 

not exceed X hours. 

Maximum travel times on arterial adjacent to freeway to not 

exceed X percent higher than the free-flow travel time. 

4.6.4 Corridor Concept of Operations 

The corridor concept of operations is a formal document that provides a high-level, user-oriented 

view of operations in a specific corridor. It is developed in part to help communicate this view to 

the other stakeholders and to solicit their feedback. The corridor concept of operations provides a 

description of the current system, operating practices and policies, and existing capabilities. It 

lays out the program concept, explains how the corridor system is expected to work once it is in 

operation, and identifies the responsibilities of the various stakeholders for making this happen. 

The goals, objectives, and performance measures of a proposed operation are also documented. 

The process of developing a concept of operations for a corridor should involve all stakeholders 

and serve to build consensus in defining the goals and objectives; provide an initial, definitive 

expression of how functions are performed, thereby supporting resource planning; and identify 

the interactions between organizations. 

The day-to-day/recurring operations concept of operations needs to identify: 

 The agencies involved. 

 The monitoring and control systems involved. 

 The interfaces involved. 

 The control objectives to be achieved. 

At this stage, the cooperating agencies address questions of what (not how) they would be 

willing to do regarding coordination of day-to-day activities in the corridor. The general 

strategies to be considered include: 

 Traveler Information. 

 Traffic management and control. 

 Shared information and resources. 

The development of a concept of operations allows the participating agencies to agree on what 

they wish to accomplish and to lay the framework for how that will be done. For example, are 

the agencies willing to agree to common cycle lengths in their adjacent signal systems? This is 

an example of an issue the agencies should resolve before moving to the more detailed level of 

discussion. 
102

As part of the development of a concept of operations, consider the following points: 

 Does stakeholder consensus exist to support coordinated day-to-day management? 

 If stakeholder consensus must be established, who will be the champion and organize a 

workshop or forum to demonstrate the benefits? 

 What is the level of stakeholder commitment of personnel and funding resources? 

 What policy changes, if any, are needed to implement a coordinated day-to-day management 

program (such as legislation allowing shared operations)? 

 What organizational structure will be established for the day-to-day management program? 

The concept of operations document could include the following sections: 

 Summary of the overall goals of day-to-day management. 

 Description of the corridor and the stakeholders. 

 Description of the high-level problematic issues. 

 Description of types of strategies to be implemented. 

 Identification of roles and responsibilities of stakeholders. 

 Identification of polices and procedures that require modification. 

 Estimate of capital and operating costs. 

 Identification of schedule for planning, development, and implementation. 

In essence, the concept of operations phase of planning involves the “who, what, when and 

where” of day-to-day management. 

4.6.5 Refinement of Scenarios and Improvement Strategies 

The concept of operations provided the high-level scenarios to be addressed and a general 

discussion of the types of strategies to be implemented to achieve agency support. Once the 

concept of operations is agreed to, the scenarios and potential strategies need to be refined. 

Specifically, on what segments of highway and under what conditions are strategies to be 

implemented? 

The process of selecting scenarios for the concept of operations may be iterative, and the 

scenarios need to be developed into specific locations where strategies would be implemented. 

Strategies are specific actions to mitigate one of the scenarios associated with a particular traffic 

problem, which could vary by time of day. Therefore, several strategies may be required to 

achieve the desired improvement in system performance. For example, if strategies include 

running common cycle lengths across jurisdictions, the scenarios need to reflect what cycle 

lengths might be implemented during what times of the day. The agencies may chose to run 

common cycle lengths during the a.m. and p.m. peak periods, but run different strategies offpeak. Or, the analysis may conclude that because of the large number of traffic patterns 

experienced in the area, a more comprehensive approach involving an integrated traffic control 

system is necessary. 

Specific examples of candidate strategies that individual agencies might consider to achieve 

improved corridor operation include: 
103

 Coordinated traffic signal timing across jurisdictions. 

 Development of a shared traffic signal control system. 

 Coordination of ramp metering and traffic signal timing. 

 Provision of transit priority across jurisdictional boundaries. 

 Shared cameras to improve corridor operation. 

At this point the high-level strategies—general ideas of how agencies can work together—are 

focused on specific segments of roadway. In the next step, the strategies are analyzed in more 

detail to understand practical issues such as costs and potential benefits. The current objective is 

to consider taking traditional strategies beyond agency boundaries to improve corridor operation. 

What is possible technically, and what is possible practically? The answers will depend on many 

local factors. The important point is to begin the dialogue among partners to determine what is 

possible. Table 13 is an example of the types of strategies that might be applied. 

Table 13. Example strategies for day-to-day operations. 

Category Example Strategies 

Traffic Management and Control 

Freeway management Ramp closures. 

Ramp metering. 

Arterial management Lane control. 

Alternative lane operations. 

Road closures. 

Onstreet parking restrictions. 

Trailblazer signing. 

Parking management systems. 

Intersection traffic 

control 

Access and turn restrictions. 

Advance signing to improve traffic circulation. 

Traffic signal timing and coordination. 

HOV incentives 

Public transit service expansion. 

Express buses from park and ride lots. 

Charter bus service. 

Preferred parking. 

Reduced parking cost. 

Traveler Information 

En route traveler 

information 

Changeable message signs. 

HAR. 

Media. 

Static signing. 

Destination signing. 

Pretrip traveler 

information 

Internet. 

Telephone information systems. 

Public information campaign. 

Event and venue transportation guide. 

Media. 
104

Table 13. Example strategies for day-to-day operations (continued). 

Category Example Strategies 

Shared Information and Resources 

Incident response 

Motorist service patrols. 

Wreckers. 

Portable DMSs. 

Traffic surveillance 

CCTV systems. 

Field observation. 

Aerial observation. 

Media reports. 

Portable traffic management systems. 

Information 

systems 

Incident reports. 

Construction activities. 

Special event schedules. 

Shared resources represent one of the potential major benefits of coordinated operations. 

Through shared resources, the collaborating agencies can obtain more information and make 

available more information than they can individually. Since day-to-day congestion frequently 

has the largest ongoing impact on operations, shared resources is a win-win proposition. 

The next section will discuss how strategies can be packaged to achieve day-to-day coordinated 

corridor management. The packaging is an iterative process of evaluating the potential benefits 

and the costs of implementing. 

4.6.6 Evaluation and Selection of Strategies 

A strategy may be perceived to be positive, but a more detailed analysis may show it to be 

counterproductive. During the process of selecting the specific strategies partners assess both the 

costs and the benefits of the strategies and the various agencies’ ability to implement the 

strategies. A strategy may be technically feasible, but not selected because it is beyond the 

resources available or inconsistent with community values. 

As the strategies are being considered, the following issues will ultimately have to be considered 

as the strategies are being evaluated: 

 Roles, responsibilities, and procedures. 

 Infrastructure operating and maintenance needs and costs. 

 Implementation priorities and schedule. 

 Updating process. 

Each of the agencies must be comfortable with the strategies and be capable of implementation. 

The degree of sophistication of the strategies will depend on the current capabilities of the 

agencies and the degree to which the agencies desire to invest in technology and/or staffing to 

achieve better operations. 
105

The evaluation of strategies may vary from qualitative to quantitative. Providing integrated 

traveler information may be evaluated qualitatively because the impacts are hard to assess and 

the potential for problems minimal. A strategy to upgrade traffic signal control systems will 

require extensive analysis to determine the costs and the benefits. In some cases, more 

sophisticated tools such as simulation models may be required to determine the feasibility and 

appropriateness of a strategy. Information on the benefits and costs of different strategies may be 

found on the FHWA Web site at: http://www.itsdocs.fhwa.dot.gov/jpodocs/repts_te/13772.html. 

The analytic tools that can determine the impact of day-to-day traffic operations on roadways are 

too numerous to discuss in this document. However, information is available from the FHWA 

Office of Operations’ Web site: http://www.ops.fhwa.dot.gov/trafficanalysistools/toolbox.htm. 

In planning the day-to-day operations strategies, there are questions which should be considered, 

such as: 

 What is the cost of various coordination efforts? 

 What resources are available? 

The process of strategies selection may be simple or complex depending upon the nature of the 

problem being addressed and the need for quantification of benefits. In many cases, the strategies 

will be more dependent upon consensus among the stakeholders than analytical analysis. 

The candidate list of strategies is further evaluated from an institutional and financial basis. For 

example, while it might be desirable to upgrade the traffic signal system, the cost to implement 

may be prohibitive. An approach using existing equipment may be less flexible, but will 

nevertheless be beneficial. 

The following factors can be used to evaluate potential traveler information, traffic management 

and control, and shared information and resource strategies that can be used for day-to-day 

coordination of freeway and arterial roadways: 

 Capacity impacts. 

 Volume of traffic affected. 

 Funding. 

 ITS deployment that is available (existing or to be installed). 

Upon completion of this step, a detailed understanding of what strategies are feasible and 

supported by the corridor agencies shall be realized. The next step is to package all of the 

strategies in a corridor implementation plan, which is the formal document, which can be used to 

secure the funding necessary to advance the program to design. 

4.6.7 Corridor Implementation Plan 

The corridor implementation plan is the product of the decisionmaking component of the CFA 

operations framework. It documents all the steps previously undertaken with sufficient detail to 

take the project or projects developed for improved corridor operations to implementation. A full 

discussion of the corridor implementation plan and its contents can be found in section 3.9. 
106

Some issues that need to be addressed in the corridor implementation plan for day-to-day 

operations include: 

 Designation of responsibilities (who is allowed to change signal timing, close ramps, etc.). 

 Initial funding and resources (agency personnel, consultant, and contractor) needed for design. 

 Funding and responsibility for construction, if required. 

 Responsibility and funding for operation and maintenance. 

 Overall schedule for deployment projects. 

 Evaluation criteria (performance measure). 

4.6.8 Design and Development 

The design step is the beginning of the implementation part of the framework, serving to 

transform the corridor implementation plan concepts into projects that are able to be 

implemented. A full discussion of this topic can be found above in section 3.10. 

The next step is packaging the strategies into an operations plan. An example of packaging 

various strategies into an operations plan was shown previously in figure 16. 

4.6.9 Implementation 

The deployment phase includes activities in preparation for implementation and the various steps 

necessary to implement the system designed in the previous step. A comprehensive discussion of 

the implementation phase can be found in section 3.11. 

4.6.10 Operations and Maintenance 

Operations and maintenance are often overlooked with serious negative consequences. Without 

ongoing support for a project, its potential will not be achieved. Operations and maintenance 

must become a part of the routine operation of the agencies. In addition, someone may need to be 

designated to handle the coordination of the unique requirements of shared operations and 

management of the corridor. 

Within an agency, there needs to be someone responsible for coordination of the operations and 

maintenance of any mitigation strategies. Where possible, the champion should encourage 

consideration of incorporating this activity as part of an existing TMC or operation. 

4.6.11 Continuous Improvement 

Continuous improvement should be well-integrated into the overall process. Ideally the 

performance monitoring system provides feedback on both the success of individual operations 

plans and the need for other actions. In addition, regular stakeholders meetings would be 

advantageous as a means of facilitating ongoing communications. At these meetings, 

stakeholders discuss experiences with coordinated operations in order to refine existing 

operations. It would also be desirable to meet annually to broadly review the program and overall 

operations plans. 
107

The best means of determining the effectiveness of the day-to-day corridor management program 

is to establish a performance monitoring system. A number of resources are available from 

FHWA (http://www.ops.fhwa.dot.gov/perf_measurement/index.htm). By continually monitoring 

performance, problems are more easily identified. 

4.7 Summary 

This chapter has demonstrated how the CFA operations framework can be applied to incidents, 

work zones, special events, and day-to-day operations. As a result of this discussion, the reader 

should recognize that taking a corridor perspective through the framework presented can 

improve freeway and arterial operations under various congestion-causing problems. The next 

chapter discusses supporting technologies and ITS elements. 

109

5 SUPPORTING TECHNOLOGIES AND ITS ELEMENTS 

5.1 Purpose 

This chapter provides an overview of the categorical technologies needed to share information in 

a timely manner and coordinate freeway and arterial operations. In no way is this chapter a 

definitive thesis on the issue of ITS technologies. At best it is a sampling of what is a needed and 

dynamic aspect of traffic control for corridor management. In many respects, coordinating traffic 

operations on a corridor is the embodiment of the ITS philosophy, which is “to enhance existing 

transportation systems operations through the application of new and emerging methods and 

technologies.”(26) Upon completion of this chapter, the reader should have a basic understanding 

of the electronic infrastructure and system interfaces that are available to support the proactive 

management of travel within a freeway corridor. In essence, the reader will learn about the 

technology that supports the goals of CFA operations. But technology must not only support 

better operations, it must also be cost effective. Technology assessment should therefore drive 

the needs of the application(s). 

5.2 Introduction 

CFA is about process and technology. The process for coordinating freeway and arterial 

operations described in chapters 3 and 4, set the stage for coordinated operations such that 

regional stakeholders might optimize vehicular throughput associated with incidents, work 

zones, special events, and day-to-day operations. This chapter describes some of the software 

and hardware tools available to permit CFA operations. The concepts of ITS promote new 

methods and devices, making technology more transitional than the process. Therefore it is 

hoped that the reader will look beyond the methods and devices currently used in their particular 

region. As discussed in section 5.4.1.1, advanced sensor technology integrated with CCTV 

surveillance and new approaches to their use offer considerable advantages in timely recognition 

of traffic incidents and the variable nature of traffic volumes. 

5.3 Information Sharing 

This document places considerable emphasis upon interagency cooperation and communication 

and thinking in terms of region and corridor instead of agency or municipality. One of the 

essential outputs of a cooperative working agreement is sharing information. While the purpose 

of this chapter is to present technology enhancements for sharing information, consider one 

relatively low-tech device: the telephone, provides a very high level of information sharing. With 

only a telephone, agencies can take the first step toward 

corridor management operations if the proper planning, 

as described throughout this document, has taken place. 

But sharing information is not enough. Sharing 

information must lead to effective cooperation in the 

context of corridorwide thinking and action. The corridor 

must be treated as a dynamic, interconnected system. 

Sharing information must lead to effective 

cooperation in the context of corridorwide 

thinking and action. The corridor must be 

treated as a dynamic, interconnected 

system. 
110

The direct communication between different agencies and municipalities sharing historic traffic 

count information, growth trends, accident data, upcoming work zone repairs, etc., is the “icebreaker” for more sophisticated data sharing. Human interaction, trust, and mutual benefit are the 

underpinning of even the most sophisticated electronic data-sharing network. 

On both freeways and arterials, means of collecting data to facilitate coordinated operations may 

already be in place. Detection and surveillance, for example, are often part of many freeway and 

arterial control systems. While such systems are intended to serve the agency and the facility 

upon which they were installed, they can, with little modification, be interconnected for purposes 

of information sharing. The objective of using technology in a CFA environment is to gain realtime information that can be acted upon so that incidents and activities in the dynamic traffic 

stream are altered or corrected before they become major problems. 

Figure 19 shows the three principal parts of the logical system that drives successful 

coordination: 

 Travelers (users). 

 Freeway systems. 

 Arterial systems. 

Coordination is about sharing data or information that is useful to others, as demonstrated in 

figure 19. This is important because in many States, multiple agencies operate freeways and 

arterials. State DOTs typically own and maintain the freeway system and some major arterials, 

and city or county agencies are responsible for most arterials and some secondary arterial roads. 

Through coordinated actions, the operation of these separate systems can be made more useful 

from a user perspective. To achieve this result, information needs to be shared effectively. Data 

collection and sharing can be accomplished through a variety of ITS technologies. 

Travelers can get information on arterial and freeway traffic conditions through a variety of 

means, many of which they already rely upon. DMSs, HAR, and radio traffic reports can all be 

used to advise drivers of conditions as they travel. Pretrip information can be made available via 

the Internet or by phone. Automated systems can also be tied to in-vehicle navigation units to 

provide dynamic route guidance. 
111

Figure 19. Chart. Traveler interface with technology systems. 

5.4 Technology and ITS Elements 

Technology plays a role in any CFA plan. The level of ITS deployment on a region’s freeways 

and arterials is not the main driver in developing CFA solutions. What is more likely to drive the 

CFA process is whether the solution is dependent upon the existence of an already-deployed 

technology or is only enhanced by that particular technology. As an example, route diversion 

strategies based upon daily peak period traffic flows can be developed with historical traffic data 

alone. Such a strategy could be significantly enhanced by real-time data from an array of sensors 

and surveillance cameras but the strategy deployment is not wholly dependant upon the 

technology. Conversely, incident management strategies that require immediate identification 

and verification of incidents at critical links in the roadway system, e.g., bridges, tunnels, and 

high security locations, will require technologies to be deployed for the solution to work. ITS 

elements that may support CFA operations can be grouped as follows: 

 Traffic data collection systems. 

 Traffic control systems. 

 Information dissemination systems. 

 Communications networks and systems. 

 Data analysis systems. 
112

The following sections describe these infrastructure elements and their role in CFA deployment. 

The appendix details a recommended procedure for the actual performance of such an inventory. 

5.4.1 Traffic Data Collection Systems 

The primary source of traffic flow information is the traffic sensor; however, several additional 

data collection systems have been developed primarily for ITS applications. These data 

collection systems can be used to gather traffic information on both freeways and arterials. There 

are several different types of data collection systems of varying age and capability already in 

place in any urban (and increasingly suburban and rural) setting. Examples of traffic data 

collection systems include the following five areas: 

1. Traffic sampling sensors. 

2. Motorist call-in systems. 

3. Automated Vehicle Location Systems. 

4. Surveillance cameras. 

5. Road weather information systems. 

5.4.1.1 Traffic Sampling Sensors 

Traffic sensor (detector) is an all-encompassing term for the generic device used by the traffic 

engineering community to measure traffic flow. Traffic sensors play a primary role in CFA data 

sharing and in CFA-shared operations. As previously noted, a variety of technologies can do 

much the same thing: namely, detect traffic. Some technologies require pavement intrusion, and 

some are mounted overhead. The real difference in sensors lies in their capabilities. There are 

only two kinds of traffic sensors: the static or, more commonly, point measurement, and the 

dynamic sensor, measuring flow characteristics. This important distinction is misunderstood or 

ignored by many even in the transportation community. Sensors of one type or another are 

essential to virtually every CFA solution involving traffic monitoring and control on freeways 

and arterials. 

Some examples of existing detector technology commonly found in freeway and arterial traffic 

control applications include: 

 

• In-pavement wire magnetic induction (loop detector). 

• In-pavement magnetometers. 

• Microwave/radar. 

• Acoustic. 

• Laser. 

• Digital Image (CCTV). 

Traffic sensors can be as simple as point measurement detectors (loops) or as sophisticated as 

dynamic vehicle tracking sensors that are capable of measuring multiple traffic parameters of an 

individual vehicle or a collective group (vehicle queue) within a traffic stream. Depending on the 

detector type deployed, the detector can potentially measure the following traffic parameters: 
113

 Speed. 

 Acceleration and deceleration). 

 Traveltime. 

 Vehicle location. 

 Volume. 

 Stopped time (arterials). 

 Vehicle classification. 

 Occupancy. 

 Queuing. 

 Stopped Vehicles. 

 Density. 

FHWA has been promoting the development of more advanced traffic sensors since the mid1970s. By the mid-1980s, digital image sensors based on CCTV that could track individual and 

collective groups of vehicles in a traffic stream were being developed. 

The availability of cheap, robust CCTV equipment has allowed sensors based on this technology 

to be cost competitive with other sensor technologies. The sensor itself is simply software and 

therefore can be located anywhere the electronic CCTV image is available, such as a TMC. More 

information on traffic sensors is available in the FHWA Traffic Detector Handbook.

(27)

5.4.1.2 Motorist Call-In Systems 

For many years motorist call-in boxes have been placed along freeways primarily to aid stranded 

motorists. Over the past decade newer and more reliable technologies have assumed the role for 

most of the call-in boxes. Often the technology replacing the call-in box does not have as its 

primary mission “helping stranded motorists.” Cell phones are an obvious example of a 

technology that assists a stranded motorist in securing assistance. Such new technologies often 

bring additional and better ways for transportation officials to monitor and control traffic. As the 

population of cell phones with motorists in the traffic has increased, so has the reliability of 

anonymous signal tracking to monitor general route traffic flow parameters. Live calls from 

motorist in the vicinity of an incident or reporting traffic congestion have increasingly proven 

reliable tools as the number of cell users increases. 

5.4.1.3 Automated Vehicle Location 

There are a variety of reasons why it is important to determine the whereabouts of a particular 

vehicle. One of the obvious needs is tracking explosives, toxic chemicals, and hazardous nuclear 

waste to insure public safety. Specific duty-cycle-vehicle fleets such as transit buses, emergency 

vehicles, and delivery vehicles operations also benefit from knowing the specific location of fleet 

vehicles. At present, several technologies permit such tracking; e.g., global position systems 

(GPS) and radio transponders. The ease, cost effectiveness, and multiple uses of GPS suggest 

that this technology will continue to become pervasive in many and varied fleet monitoring 

operations. Using the tracking points of fleet vehicles immersed in the traffic stream permits 

real-time monitoring of traffic system conditions. While this would not be the only means of 

monitoring a CFA solution, it serves as a powerful overview of the systemic situation. 
114

5.4.1.4 Surveillance Cameras 

Today, surveillance cameras and CCTV systems are reliable and cost effective. They provide 

transportation systems operators with a live visual image of traffic conditions and to some extent 

weather conditions. Surveillance cameras have been used in security systems for several decades 

and increasingly, in the past decade, for remote infrastructure monitoring. The digital image of 

surveillance cameras serves as the input for most advanced dynamic sensors. Therefore, a single 

technology deployed along the roadside can serve as a visual monitor of traffic conditions and 

the digital source to measure the dynamics of the traffic stream. Such a dual capability can be an 

essential component in several CFA solutions. 

5.4.1.5 Road Weather Information Systems (RWIS) 

Weather conditions can be a major factor in the performance of the traffic stream. In some 

situations however, weather is a critical component of safe traffic stream performance. A variety 

of weather reporting stations have been deployed for many years in locations where changing 

conditions are a significant hazard to public safety. One of the earliest systems was installed 

along the New Jersey Turnpike to detect the presence of rapid fog formation. Using variable 

message signs and variable speed limit signs motorists are informed and directed when 

conditions warranted. The concepts of RWIS has expanded as a result of ITS awareness, and 

deployments now include a variety of sensors and pavement monitoring systems permitting 

system operators to gauge the need for roadway salting and snow plowing ahead of actual icing 

conditions on the pavement surface. The AZTech system mentioned earlier in this document 

employs an RWIS to monitor for wind conditions and dust storms. A variety of CFA strategies 

might be predicated on weather-related conditions. 

Some of the data collected by RWIS may include the following road-weather related 

information: 

• Pavement temperature. 

• Humidity. 

• Wind speed. 

• Air temperature. 

• Pavement moisture. 

• Precipitation. 

Transportation department dispatchers can use this information, for example, to anticipate the 

occurrence of icing on roadways and bridges and in turn, dispatch road crews to place de-icing 

chemicals. 

5.4.2 Traffic Control Systems 

Examples of traffic control systems commonly used on freeways include: 

 Ramp meters. 

 DMSs. 

 Reversible lane/HOV lane/express lane systems. 

 Lane controller signals. 
115

 Dynamic speed control. 

 Lane restriction by vehicle classification. 

Ramp metering systems are typically controlled locally with ramp detector data inputs and a 

central system connection for manual overrides and turning the system on or off. More robust 

systems employ algorithms with freeway mainline and arterial detector data inputs to optimize 

traffic on all systems and achieve appropriate impacts on the arterials and freeways. 

Freeway lane controllers typically use a green down arrow above a lane to indicate the lane is 

open and a red X above a lane to indicate a closed lane. Lane controllers can be used on freeways 

to indicate that a lane is closed ahead, often due to construction or an incident. Freeways that 

allow vehicles to travel on the shoulder during peak periods often use lane controllers to indicate 

that the shoulder is clear for use, which enables operators to immediately close the lane with a 

red X if the shoulder becomes blocked. 

Lane controllers are also used on reversible lane freeway systems to guide motorists. Reversible 

lane freeway systems (i.e., express lanes) are often located in the middle of a freeway with 

limited entrance and egress points, and they are sometimes dedicated to HOV access only. 

Reversible lanes are often used on bridges as well to manage directional traffic flow. Reversible 

lane systems on freeways are most often controlled manually for safety purposes to ensure that 

the facility is free of vehicles prior to reversing the lane(s) direction. Most agencies follow a 

standard peak hour schedule for reversing the travel lanes, but implement schedule changes to 

accommodate traffic from special events, construction, and even major incidents. 

Examples of traffic control systems commonly used on arterials include: 

 Intersection traffic signals. 

 Interconnected traffic control systems. 

 Lane controller signals. 

 Reversible lane/HOV lane systems. 

Although traffic signal control systems are mostly or fully automated, their means of control 

vary from time-of-day control to actuated control to traffic adaptive control systems. Connection 

to a central control facility enables operator awareness of traffic conditions. It also enables traffic 

management while allowing the operator to interrupt system control and manually override 

traffic signal systems to improve operations if it becomes necessary to respond to the effects of 

special events traffic, construction, and incidents. 

Lane controllers and reversible lane systems on arterials are used and operated in a similar 

fashion to freeway reversible lane operations. However, arterials typically do not have separated 

facilities for reversible lanes. This enables use of automation to control the systems because 

motorists can merge into adjacent nonreversible lanes when the lane controllers switch lane 

operations. 

5.4.3 Information Dissemination Systems 

All pretrip information dissemination systems require the general public to perform an action to 

obtain traveler information. Pretrip information dissemination systems include: 
116

 Traffic radio. 

 Internet. 

 511 telephone traveler information service. 

The only en route information dissemination systems which do not require motorist action to 

obtain traffic information are DMSs and static signs with flashing beacons. DMSs allow 

operators to disseminate any information to the traveling public, although it is limited by the 

amount of time drivers have to read the information. The static sign with flashing beacon 

implementation is limited to only providing one static message to motorists of a condition, such 

as “Traffic Congestion Ahead When Flashing.” 

En route systems may include: 

 Traffic radio. 

 HAR. 

 511 telephone traveler information service. 

 Personal devices. 

 DMSs. 

All of the pretrip and en route information dissemination systems can be used to inform 

motorists of travel conditions on both freeways and arterials. 

5.4.4 Communications Networks and Systems 

ITS infrastructures rely heavily on communications networks. Hard wire and/or wireless 

networks are necessary for all CFA operations applications; they typically employ a transmitter 

at the device end and receiver at a communications hub or control center to enable 

communications between and among field and control center systems. 

The final ITS infrastructure element is communications systems, which include systems that 

enable communications between centers. In fully integrated systems, the communication system 

might make use of control center software and communications networks to: 

 Enable all stakeholders to view any information that may be pertinent to their operations. 

 Alert the appropriate stakeholders of incidents within their jurisdictions and/or incidents that 

may affect operations within their jurisdictions. 

 Operate their own traffic control systems and field devices owned by other agencies in 

accordance with the restrictions allowed by the system. 

Distributed control centers without system integration may make use of common 

communications means, such as telephones and the Internet, for transmitting information 

between stakeholders. Communications systems enable CFA operations agencies and their 

systems. 
117

5.4.5 Data Analysis Systems 

Traffic data analysis systems most often reside on central system software at a traffic control 

center, but they can also reside locally in a field cabinet with software residing on a processor or 

controller. Data analysis systems for freeways are considerably different from those for arterials. 

Although the concepts may be the same, the data analysis systems are different because of the 

differences in arterial and freeway operations and traffic patterns. 

Data analysis systems can be categorized as one of the following: 

 Systems that analyze outputs from traffic data collection systems for inputs to traffic control 

systems. 

 Systems that analyze outputs from traffic data collection systems to alert control center 

operators to a traffic condition. 

 Systems that analyze outputs from traffic data collection systems to create an input to 

information dissemination systems. 

Data analysis systems typically become more robust as the number of data elements analyzed 

increases, whether the increase is in the type of data elements or the number of data elements. 

Examples of data analysis systems include: 

 Incident detection algorithms—control center software modules that analyze detector data 

outputs and alert operators of traffic conditions that are indicative of an incident. 

 Parking management systems—use detector data output as input to local or control center 

software to either determine the number of remaining available parking spaces or simply 

determine whether the parking lot is full, with a system output to information dissemination 

devices of parking availability. 

 Ramp metering control systems—can apply local or central data analysis and control and 

provide varying levels of data analysis ranging from a low-technology system that only 

analyzes ramp detector input to locally control the ramp meter all the way up to a robust 

system that analyzes ramp detector data, upstream and downstream freeway mainline detector 

data, and arterial detector data with control center software that controls ramp meters to 

optimize freeway and arterial operations. 

 Traveltime computation and analysis systems—select the appropriate inputs to information 

dissemination systems, such as DMSs, Internet traffic flow maps, and automated traveltime 

information on 511 telephone information service systems. 

5.4.6 ITS Architecture and Standards 

The National ITS Architecture provides a common framework for planning, defining, and 

integrating ITS. It reflects the contributions of a broad cross-section of the ITS community 

(transportation practitioners, systems engineers, system developers, technology specialists, 

consultants, etc.). The architecture defines: 
118

 The functions (e.g., gather traffic information or request a route) that are required for ITS 

 The physical entities or subsystems where these functions reside (e.g., the field or the vehicle). 

 The information flows and data flows that connect these functions and physical subsystems 

together into an integrated system. 

Each State and MPO is required to develop its own ITS architecture modeled on the National 

ITS Architecture in order to participate fully and effectively in the program and be eligible for 

Federal funding. More information on developing an ITS architecture can be found at 

http://www.ops.fhwa.dot.gov/its_arch_imp/index.htm. 

From its inception in 1996 to the present, the ITS Standards Program am has had a primary focus 

on the development of open, nonproprietary communication standards and protocols that 

facilitate the integration of ITS devices and networks. To accomplish this challenging mission, 

the ITS Standards Program collaborates with seven national standard development organizations 

to coordinate and accelerate the development of ITS standards. Collaborating allows the ITS 

Standards Program to tap into existing standards development processes, thus eliminating the 

need to create new procedures. Collaborating also facilitates the engagement of industry experts 

who help inform the technical discussion of volunteer committees, of consultants who capture 

the working group’s intent when writing the standard, and of public sector transportation 

professionals who bring an invaluable perspective on real-world ITS implementations. 

The ITS standards are used at the intersection between both similar and different types of ITS 

devices and components. The standards define how the components exchange information and 

work together to deliver the user services desired by State and local agencies from their defined 

systems. 

The evaluation found that standards allow the “interconnections” to be open to all of the 

elements — open to any device, vehicle, center, or traveler to connect to and receive or transmit 

data to any other element in the system. Standards also define how the data is formatted so they 

are unambiguously recognized by all the other elements in the system. More information about 

ITS standards can be found at http://www.standards.its.dot.gov/default.asp. 

5.5 Summary 

CFA operations require some element of each categorical technology described in this chapter. 

In the most basic systems, data input can be as simple as a police officer’s observation of a 

traffic blocking incident or as sophisticated and dynamic as an array of roadway sensors 

monitoring all traffic parameters and immediately noting any anomaly to a TMC. As well, the 

most basic way to get a message to the motorist is through simple posted signs. Enhancing 

simple, basic signs are technologies such as HAR, DMS, and GPS navigation systems. In 

developing and deploying technology elements associated with CFA, several main points should 

be considered: 

 Technology needs should be chosen through consensus of the stakeholders. 

 Technology needs should be driven by specific CFA strategies chosen through the 11-step 

CFA framework. 

 Operations and maintenance needs of new technologies must be considered. 
119

The key element in the CFA process is information sharing. The modifier is timeliness, or how 

quickly the information needed to make a decision. The need for speed will dictate how much 

and what type of technology is necessary to optimize traffic flow on the corridor in question. The 

next chapter provides examples of CFA operations. 

121 

6 EXAMPLES OF CFA OPERATIONS 

In certain respects this last chapter takes the reader back to the beginning of this document 

because its focus is to reaffirm the benefits of a corridor mindset of looking at transportation 

issues. The chapter presents two very different examples of CFA operations. The first example 

showcases a real-world application of the CFA operations framework. The second example uses 

a hypothetical major incident and the resulting operations both with and without CFA strategies 

in place. 

6.1 Example 1: Developing Incident Management Route Diversion 

Strategies in Northern Virginia 

The following example focuses on the planning and analysis required to develop relatively 

simple, low-tech coordination between freeway and arterial operations in a heavily traveled 

suburban area. The example is based in Springfield, VA, a suburb of Washington, DC. In this 

case, many of the institutional issues are less complex than typical coordinated operations given 

that the same agency, the Virginia Department of Transportation (VDOT), is responsible for 

freeway and arterial operations in this area. This example uses the CFA operations framework 

detailed in chapter 3. 

6.1.1 Problem Identification 

In the heavily congested Northern Virginia region, VDOT is responsible for operating the vast 

majority of roadways. The agency operates a freeway management system, the Northern Virginia 

Smart Traffic Center (NVSTC) and an arterial signal control system, the Northern Virginia 

Smart Traffic Signal Systems (NVSTSS). While each system is well suited to manage traffic on 

their respective portions of the surface transportation network, there is little technical integration 

between them. A key way that VDOT has worked to integrate freeway and arterial operations in 

the region is to use the NVSTSS to select appropriate timing plans to best accommodate 

diverting freeway traffic when alerted by the NVSTC. To date, however, VDOT generally 

selects an existing timing plan (i.e., a.m. peak, p.m. peak, off-peak) as opposed to a plan 

specifically designed to accommodate diverting freeway traffic. Despite this practice, VDOT 

traffic engineers expected that improved integrated operations can be realized by developing 

timing plans better tailored for diversion. 

To address this problem, VDOT selected a particular freeway/arterial diversion that is among the 

most frequently used in the region for a case study. This diversion is designed to accommodate 

southbound I–95 traffic in the vicinity of the Springfield Interchange (known as the “Mixing 

Bowl”) where I–95, I–395 and I–495 meet in Fairfax County, VA. As seen in figure 20, 

southbound South Van Dorn Street to westbound Franconia Road comprise VDOT’s designated 

incident diversion route in case of freeway lane(s) closure due to traffic incident, construction, or 

special event. 
122 

Figure 20. Drawing. Map of project area (black arrow shows 

the forward direction of diversion route.) 

The route is approximately 4.0 km (2.5 mi) long. Traffic signal controls along the diversion route 

are not coordinated as a single system. The four traffic controllers on the Van Dorn Street are 

coordinated and are within one zone. The signal controller at the Van Dorn Street and Franconia 

Road is uncoordinated. The first four traffic controllers on the Franconia Roads along the 

diversion routes are coordinated and belong to a separate zone. The remaining controllers are 

also coordinated but are in a different zone. 

The problem identified by VDOT engineers is to develop the best timing plans for use on 

arterials when freeway diversion occurs, making the best use of resources afforded by the 

NVSTC and NVSTSS. 

6.1.2 Institutional Considerations 

In this scenario, both the arterial and freeway systems are operated by VDOT. This greatly 

simplifies the challenge of coalition building. For many years, VDOT has worked to break down 

artificial barriers between different operating units of the organization. For example, the 

managers of the NVSTC and NVSTSS both report to the same individual within the agency. 

However, beyond organizational structure, the key aspect to coalition building is a commitment 

to continued communication between operators of the NVSTC and NVSTSS. 
123 

6.1.3 Goals, Objectives, and Performance Measures 

There are multiple, and often conflicting, goals associated with this form of freeway and arterial 

coordinated operations. The goals are as follows: 

 To maximize throughput of diverting vehicles. 

 To minimize traveltime of diverting vehicles. 

 To minimize delay for motorists in the diversion zone system. 

Clearly, these goals are conflicting. As one gives more and more green time to the diversion 

movement, side street traffic suffers greater with each delay. Careful attention to the balance of 

these goals was important to VDOT in considering this form of integrated operations. 

Performance measures selected to measure achievement of the goals and objectives were simply 

traveltime and throughput. 

6.1.4 Corridor Concept of Operations 

The concept of operations needs to identify: 

 The agencies involved. 

 The monitoring and control systems involved. 

 The interfaces involved. 

 The control objectives to be achieved. 

The existing freeway (NVSTC) and arterial (NVSTSS) management systems are to be used in a 

coordinated manner to affect a freeway diversion route in response to freeway congestion. The 

system to be used is basically a low-tech implementation of a specific diversion route, and 

optimizing the system for the diversion. It primarily involves improved traffic signal timings. 

The proposed strategy is totally on the State highway system, minimizing the need for 

stakeholder consensus building. The amount of resources required to develop, operate, and 

maintain is minimal. No policy changes are required. 

As part of the development of a concept of operations, the following points were considered: 

 Does stakeholder consensus exist to support coordinated day-to-day management? 

 If stakeholder consensus must be established, who will be the champion and organize a 

workshop or forum to demonstrate the benefits? 

 What is the level of stakeholder commitment of personnel and funding resources? 

 What policy changes, if any, are needed to implement a coordinated day-to-day management 

program (such as legislation allowing shared operations)? 

 What organizational structure will be established for the day-to-day management program? 

6.1.5 Corridor Scenarios and Operations Strategies 

Alternatives that VDOT is considering to address this problem include both new timing 

strategies and modest geometric changes. In addition, new designs must be compared to the 
124 

current operations strategy to assess if they result in significant improvements that warrant full 

development. 

First, it is important to describe the capabilities provided by the NVSTSS. The system controls 

more than 1,000 signalized intersections in the region using a centralized, computer-based traffic 

signal control system. The system allows traffic signal operators to monitor traffic flows at 

intersections through a graphical user interface, to update signal timing plans in real time, and to 

maintain a database of signal timing plans and traffic data. Thus, the system will fully support 

the development of customized timing plans to dynamically activate when freeway to arterial 

diversion is necessary. 

 

Currently, when a major crash occurs on a freeway, the NVSTC relays the location and severity 

of the crash to an NVSTSS operator. Then, the NVSTSS operator checks traffic conditions along 

the diversion route and updates signal timing plan accordingly. The current practice is to use the 

peak timing plan corresponding to the direction of the diversion. In the Van Dorn/Franconia 

diversion considered in this case study, the p.m. peak timing plan is implemented. 

The primary alternative considered is a signal-timing plan optimized to accommodate diverting 

traffic flow. In this case, all 10 intersections of the diversion route are coordinated. The next 

section will detail the approach used to design this plan. In addition, based on experience and 

field inspection, a simple geometric change was considered as an alternative. Currently, the 

I–495 exit to the diversion route (southbound Van Dorn Street) consists of three lanes (one 

exclusive left turn, one exclusive right turn and one left and right turn shared lanes). An 

alternative was to modify this facility to include one exclusive left turn lane and two exclusive 

right turn lanes to better accommodate diversion. 

Combining the issues discussed above results in three alternatives for consideration: 

 Alternative 1: the p.m. peak period signal timing plan (a ‘do nothing’ alternative). 

 Alternative 2: the diversion optimized signal-timing plan without I–495 exit changes. 

 Alternative 3: the diversion optimized signal-timing plan with I–495 exit changes. 

6.1.6 Evaluation and Selection of Strategies 

The scenarios considered were weekday off-peak period and p.m. peak period. These were 

chosen to examine diversion during already congested conditions (p.m. peak) when it is likely 

that little excess demand from the freeway can be serviced by the arterials and during 

uncongested conditions (off-peak) when it is expected that arterial diversion is more feasible. 

The “base” projected diversion volume is assumed to be the additional volume resulting in a 

volume to capacity ratio of 0.95 at the critical intersection (in this case, the intersection of the 

I–495 exit and Van Dorn Street). Based on this definition, the base diversion volume that could 

be accommodated during off-peak was 1,670 vehicles/hour, and 100 vehicles/hour during p.m. 

peak conditions. Immediately, one will see that this clearly illustrates that very little benefit can 

be realized from diversion during the p.m. peak, given the already congested conditions of the 

arterial diversion route. However, this illustrates the potential benefits of using the route during 

off-peak. 
125 

To investigate the sensitivity of the alternatives to variations in diversion demand, the evaluation 

was conducted at the projected diversion volume, and at levels 10 percent greater and less. 

However, given that the projected additional feasible diversion demand is so low during the p.m. 

peak, the negative 10 percent scenario was not considered. 

All the alternatives for the weekday off-peak period are illustrated in figure 21 and all the 

alternatives for the p.m. peak period are illustrated in figure 22. 

Time of Day Timing Plan Alternatives Volume Level

+10% of Critical Volume *

Field Peak Critical Volume

Timing Plan

-10% of Critical Volume

+10% of Critical Volume

Optimized Off-Peak

Off-Peak Timing Plan Without Critical Volume

Geometric Change

-10% of Critical Volume

+10% of Critical Volume

Optimized Off-Peak

Timing Plan With Critical Volume

Geometric Change

-10% of Critical Volume

* Critical Volume is the critical intersection's critical movement's

demand at the volume to capacity ratio 0.95.

Figure 21. Chart. Off-peak strategy alternatives. 
126 

Time of Day Timing Plan Alternatives Volume Level

Field Peak

Timing Plan

+10% of Critical Volume

Optimized Peak

Peak Timing Plan Without

Geometric Change

Critical Volume

+10% of Critical Volume

Optimized Peak

Timing Plan With

Geometric Change

Critical Volume

* Critical Volume is the critical intersection's critical movement's

demand at the volume to capacity ratio 0.95.

Critical Volume *

Figure 22. Chart. Peak strategy alternatives. 

The design and evaluation process required the collection of large amounts of data and careful 

attention to model calibration. While it does require significant staff or consultant resources, the 

process results in a design that is well understood before field implementation. The process 

involved to develop and evaluate the alternatives can be categorized into three major tasks: 

 Acquiring and manipulating field data. 

 Developing timing plans using a traffic signal optimization software program. 

 Evaluating performance using a traffic micro-simulation software program. 

The results of the simulation testing are categorized as follows: 

 The “forward” direction of the diversion route (i.e., the experience encountered by diverting 

motorists). 

 The reverse direction of the diversion route. 

 The side street traffic (i.e., all other motorists in the system). 

The average traveltime was plotted against the cumulative throughput for each alternative. It 

revealed that a customized timing plan for diverting traffic is warranted during off-peak 

conditions only in the forward direction of the diversion route. 

The three alternatives were analyzed in the forward direction of the diversion routes during the 

weekday off-peak period at critical volume condition and revealed the following: 
127 

• An optimized timing plan during congested conditions will do little to improve diversion 

performance. 

• A customized diversion-timing plan without changing geometry is the preferred alternative in 

terms of traveltime savings and delay reduction. 

• Although the throughput is slightly higher if the geometric change is in place, the average 

traveltime and delay are higher also. 

 The average traveltime for the alternative 1 is highest while the alternatives 2 and 3 are 

comparable. 

The three alternatives were analyzed in the forward direction of the diversion routes during the 

p.m. peak period at critical volume condition and revealed the following: 

 The current design, use of the p.m. peak period timing plan, is a less attractive alternative with 

a greater average traveltime corresponding to a lower throughput of vehicles. 

 As may be expected, the reverse and side streets performance are better using the p.m. peak 

timing plan, but the values for the reverse direction are comparable. 

 In effect, diversion exacerbates the overall traffic more than helping during the p.m. peak 

period. 

The analysis showed that alternative 3 works the best during the p.m. peak period. The 

throughput of alternative 2 compared to alternative 1 is 44 more vehicles at a traveltime saving 

of 7 seconds and 5 seconds less delay. Thus the optimized timing plan with or without geometric 

change is not much better than the p.m. peak timing plan. Again the field p.m. peak timing plan 

provides a more favorable performance measure for the reverse and side streets. The analysis 

showed that diversion during the p.m. peak should be avoided, as almost no relief to freeway 

traffic will be provided while increasing arterial delay. 

6.1.7 Corridor Implementation Plan 

The corridor implementation plan for this particular scenario is simple: incorporate the newly 

developed diversion optimized timing plan into the centralized signal control system, and then 

train operators to use it during off-peak periods. 

A longer range corridor implementation plan that VDOT expects to develop after this project is 

to analyze all freeway diversion routes and develop optimized timing plans to improve this form 

of freeway and arterial integration. 

6.1.8 Design and Development 

The design of the preferred alternative, a custom diversion-timing plan for use during off-peak 

periods, is essentially complete following the signal timing optimization analysis. This can be 

implemented within the centralized signal control system. 

Based on the results of the evaluation, a design modifying lane-use restriction at the intersection 

of the I–495 exit and Van Dorn Street is not warranted. The small level of benefits seen in some 

scenarios simply does not call for the effort required to design this change. 
128 

6.1.9 Deployment 

Given the capabilities of NVSTSS’s system, implementation of this new strategy is very simple. 

The new timing plan need simply be stored for use when warranted. 

However, an important step to implement new timing plans is to validate the plans’ effectiveness 

in the field. VDOT’s NVSTSS devotes significant resources to data collection and field 

monitoring when a new timing plan is implemented. This is done to identify unexpected 

problems associated with the plan and then make minor adjustments. This is necessary because 

any model, no matter how detailed, is a simplification of the real world. Rarely can they capture 

every nuance that may impact the performance of a timing plan. 

Unfortunately, field validation of the optimized diversion-timing plan is more difficult than 

“traditional” plans. For example, the a.m. peak occurs every weekday morning. This allows 

VDOT to gather forces and equipment to plan for the validation effort. On the other hand, VDOT 

can rarely plan for when a diversion to take place during off-peak periods. This makes it more 

difficult to adjust the plan based on field observations. 

6.1.10 Operations and Maintenance 

Operation of the proposed design is based solely on effective communications between NVSTC 

and NVSTSS operations staff. This will ensure that the plan is implemented (and replaced) as 

soon as warranted. 

Maintenance needs relate primarily to monitoring changing traffic demands in the region. As 

time progresses, and development patterns change, traffic patterns will be different than those 

used to develop the customized diversion timing plan. As these conditions change, it will be 

necessary to re-optimize the signal timings. 

6.1.11 Continuous Improvement 

As VDOT continues to identify and develop timing plans best suited for freeway diversion, it 

realizes that nothing will remain constant. The plans developed will need to be revisited on a 

frequent basis. In addition, incident debriefs between NVSTC and NVSTSS staff will be 

necessary to ensure that communications remain effective and timely. 

6.1.12 Example Summary 

This example applies the CFA framework to a relatively straightforward freeway diversion to a 

parallel arterial under congested freeway conditions. While there were minimal institutional 

issues in this case study, it does demonstrate how the analysis might be undertaken to determine 

an appropriate strategy. 

6.2 Example 2: Leveraging ITS Technologies to Enhance CFA Operations 

The above example reinforced the CFA operations process that was detailed in chapter 3. The 

following example reinforces the focus of chapter 5, the use of technologies to enhance CFA 

operations. Technologies including legacy systems, existing ITS deployments, and new systems 
129 

resulting from the CFA planning process are combined in a hypothetical example. This idealized 

example has been created to simulate a complex urban environment where several governing 

entities and multiple agencies have partnered to enhance a major east-west travel corridor. The 

situation is presented as a hypothetical example of what can happen as a result of a major 

incident without leveraging ITS technologies in a coordinated manner and how the incident can 

be more successfully handled with good usage and coordination of ITS technologies. 

Consider a major urban area situated along a navigable river with multiple east-west bridge 

crossings (figure 23). The river is also the border between two States and the urban area is 

actually two different cities in two different States. We are now, in this example, dealing with at 

least four different governing entities and several more municipal agencies and/or transportation 

authorities. Such an urban environment may have several basic ITS operating systems with 

attendant control devices and DMSs that have been deployed along many highways and bridge 

approaches over the past decade. The only effective way to alert motorists to difficulties on one 

of the bridge crossings is to share information so motorist alerts can be posted sufficiently in 

advance to allow diversions in one jurisdiction and warnings of an incident in another 

jurisdiction. 

6.2.1 Major Incident Without Leveraging ITS Technologies 

It is a typical weekday, there is a slight drizzle, and traffic is building toward the p.m. peak hour. 

4:15 p.m.—A minor fender-bender occurs on the eastbound lanes of the Northern 

Interstate river crossing linking the downtown areas of both cities. A traffic queue 

immediately starts to build on the eastbound lanes. 

4:20 p.m.—The incident is undetected by authorities. 

Eastbound traffic begins to back up to the last exit before the river, and motorists 

approaching the backup make quick decisions to bail out to the surface streets (Exit 123) 

and the old six-lane bridge crossing down river several miles. 
130 

Figure 23. Chart. A major urban area situated along a navigable river with 

multiple east-west bridge crossings. 

4:25 p.m.—The incident is still undetected by authorities. 

Westbound traffic, now slowing due to motorists distracted by the incident, experiences a 

chain reaction collision involving four cars and several injuries. A regional transit bus 

driver, westbound on the Northern Interstate river-crossing, reports the westbound 

incident to his dispatcher at the same time the original eastbound accident is reported by 

cell phone by one of the involved motorists to Red State Highway Patrol who also reports 

that “no one is injured.” 

4:30 p.m.—Blue State’s ITS TMC has a traffic flow reduction alert alarm going off and 

one of the TMC operators notes that traffic has slowed considerably at a TMC traffic 

monitoring location one mile before the Northern Interstate river crossing. A Red State 

Highway Patrolman contacts his base and reports an accident with no injuries at the same 

time the Regional Transit dispatcher reports an accident on the bridge with several 

injuries. West Bend City police dispatch is reporting unusually heavy traffic on city 

streets and severe congestion eastbound on the old six-lane arterial bridge. This is a 

particular problem for the West Bend City traffic engineer, who has programmed his 

new, ITS bridge lane-control signs and movable concrete divider to provide four lanes 

westbound and two lanes eastbound in accord with “normal p.m. peak hour traffic.” 

4:35 p.m.—West Bend City police are now hand-directing traffic to undo gridlock that 

has occurred on the streets approaching the six-lane arterial bridge which only has two 

lanes open for eastbound traffic. The oldest four-lane river crossing is now receiving the 

overflow traffic from its six-lane cousin upstream, and traffic is hopelessly backed into 
131 

West Bend City where police report several fender benders probably “due to the wet 

highways.” Emergency vehicles arrive at both the eastbound and westbound accident 

locations. 

4:45 p.m.—The local radio station, receiving 

information from its “Eye in the Sky” traffic 

chopper, is now reporting on the major bridge 

accident on Northern Interstate, jammed traffic 

regionwide, and suggesting motorists divert to the 

Southern Interstate. Unfortunately, the Southern 

Interstate bridge crossing witnessed the beginning of its long-term redecking project last 

night and is speed restricted with three narrowed lanes of traffic compared to its usual 

four lanes eastbound. 

5:00 p.m.—Situation out of control! Communications ongoing between both city traffic 

engineers and both State DOTs is unproductive. The Blue State TMC is trying to divert 

traffic well in advance of the Northern Interstate river crossing via its DMSs but it is too 

little, too late. The regional transit authority is reporting major delays on many of their 

downtown lines in both West Bend City and East Bend City. 

5:15 p.m.—The “Eye in the Sky” traffic chopper is reporting that traffic throughout the 

urban region is a mess today; little do they realize that their traffic reports, lacking 

coordination with those who operate the transportation systems, actually added to the 

chaos. 

In analyzing the scenario described above, the areas where lack of a coordinated response had 

the most impact can be summarized as follows: 

 Information was shared but was neither timely nor coordinated. 

 Delays in detecting the incident allowed congestion to spread rapidly. 

 Secondary accident with injuries occurred. 

 Transit system delayed. 

 Appropriate officials in communication were helpless. 

 Inappropriate responses by emergency units. 

 Police tied up with snarled traffic. 

 ITS systems were uncoordinated and unresponsive to incidents. 

 Substantial delay-costs to thousands of travelers in the East–West Metropolitan region. 

 No benefits from good intentions. 

6.2.2 Major Incident With Leveraging ITS Technologies 

Now consider that same major urban area where the several bridge crossings are perceived by 

the multiple agencies and governing bodies as a corridor. The proper planning has been done, a 

framework has been developed, working agreements and relationships exist, scenarios and 

response strategies have been created, and operating ITS systems have been upgraded and 

integrated such that coordinated operations are a routine occurrence. 

Even good intent and a cooperative spirit 

between governing entities may be 

inadequate to deal with the most mundane 

of traffic flow situations unless the 

processes described in this document have 

resulted in a deliberate CFA shared 

operations environment. 
132 

Once again, it is a typical weekday, there is a slight drizzle and traffic is building toward the p.m. 

peak hour. 

4:15 p.m.—A minor fender-bender occurs on the eastbound lanes of the Northern 

Interstate river crossing linking the downtown areas of both cities. A traffic queue 

immediately starts to build on the eastbound lanes. 

4:16 p.m.—The incident is detected by the surveillance and data collection cameras that 

cover 100 percent of this and all bridges in the urban region and is verified at the regional 

TMC. 

4:17 p.m.—The lane control signs on the bridge immediately configure that lane out of 

service. Variable speed signs reduce the speed limit both eastbound and westbound on the 

bridge from 88.5 kilometers per hour (km/h) (55 miles per hour (mi/h)) to 56.3 km/h 

(35mi/h) in their emergency flashing mode. The DMSs at each bridge approach flash an 

accident alert. The eastbound DMS notes, “Accident ahead. Right lane closed,” The 

westbound DMS notes, “Accident ahead. All lanes open. Reduce speed.” 

4:18 p.m.—The emergency response team is dispatched to remove the damaged vehicles. 

Preplanned diversion strategies in accord with “reduced eastbound Northern Interstate 

bridge flow during the p.m. peak hour scenario” are immediately brought online. Traffic 

eastbound is advised by DMS upstream that an accident has occurred on the eastbound 

lanes, the right lane is closed, and motorists may exit at Exit 123 and follow signs to the 

old six-lane river crossing. The surface street traffic signal system in West Bend City is 

instructed by the TMC to optimize southbound flow at the same time the six-lane bridge 

transition from its “normal p.m. peak hour operation” of four lanes westbound and two 

lanes eastbound is revised to allow three lanes in each direction. The regular transition to 

four lanes westbound and two lanes eastbound is delayed for the duration of the incident. 

4:19 p.m.—The “Eye in the Sky” traffic chopper is reporting “slight delays on the 

Northern Interstate bridge crossing but it seems to be clearing. We’ll fly on down to the 

bridge redecking on the Southern Interstate to see how the construction traffic is moving 

even though the TMC folks tell us traffic is moving normally.” 

4:30 p.m.—The incident is removed and the lane declared open via lane control signs. 

4:35 p.m.—The incident over, traffic returns to normal. The West Bend City signal 

system is in normal p.m. peak hour operation, and the old six-lane bridge makes the 

transition to its normal p.m. peak hour operation. 

In analyzing the scenario described above, the most significant successes and their results can be 

summarized as follows: 

 Information was shared in a timely fashion. This was the result of a decision to install state-ofthe-art dynamic video sensors monitoring 100 percent of the paved surface on all bridge 

crossings for data collection and incident detection. Advanced sensor software, located at the 
133 

regional TMC continually monitored all traffic parameters and provided immediate notice of 

any stopped vehicle on any of the urban area bridges. 

 Coordinated operations through the new “East-West Regional TMC” responded rapidly and 

effectively. This was the result of a CFA decision to combine functions into a regional 

operation with preplanned strategies for a host of probable scenarios. 

 The preplanned TAP (Transit Alternative Priority) Routes for alternate bridge crossings 

(stakeholders gave transit priority over passenger vehicles during incidents) were considered 

but proved unnecessary for this event. 

 There was no secondary accident because of the use of integrated ITS systems informing and 

diverting motorists via DMSs and controlling the traffic stream with lane and speed control 

signing. 

 The traffic surge on diverted-to routes was handled by appropriate ITS systems, including an 

advanced traffic responsive signal system in West Bend City. When developing the scenarios 

and strategies, it was decided that, in the best interest of both West Bend City and the greater 

metropolitan region, movable concrete barriers were not responsive enough on the old six-lane 

bridge. Instead the bridge received full CCTV surveillance and lane and speed control signing. 

 The media have continual access to the TMC, and the “Eye in the Sky” traffic chopper had 

little or no real impact on the congestion because the incident was resolved so quickly. 

 The whole event took place, was resolved, and returned to normal within 30 minutes. 

 No notice was taken of the event nor was any credit given to the positive effect of the “CFA 

corridorwide approach” to traffic management in the east-west Metropolitan region. 

While the above example is hypothetical, it is nonetheless an accurate interpretation of what 

could be done with a well-planned CFA system enhanced with off-the-shelf ITS technologies. 

Likewise the above example is intended to demonstrate a complex urban environment and the 

substantial benefits that accrue when multiple ITS deployments work as an integrated urban 

system. In so doing, it is hoped that the reader will perceive and appreciate simple applications in 

a broad variety of corridor settings. 

6.3 Summary 

With its two examples, this chapter reinforces the essential message of this entire document, 

thinking in terms of transportation corridors. In so doing, the individual facilities within the 

corridor can be better optimized to serve its region. Essential to this process are technological 

devices and methods that enhance corridor optimization. The reader is guided to the technical 

publications referenced throughout this document for detailed information about associated 

programs and ITS related technologies. 

135

APPENDIX: ITS TECHNOLOGY INVENTORY, NEEDS 

ASSESSMENT, AND INTEGRATION 

It is critical to gather detailed information about the existing infrastructure elements that support 

coordinated operations during the technology inventory, The inventory is completed to 

accurately identify locations that are deficient in deployment of data collection, traffic control, 

and information dissemination systems, as well as their related data analysis and communication 

systems. Recording details of the existing technology types, brands, protocols, and means of 

communication will enable engineers to determine whether existing technologies and their 

components are compatible, interoperable, and interchangeable. Knowledge of the existing 

systems will define the ability to communicate between them. It will also define future system 

deployments, because it is essential that new technologies deployed can communicate with, 

operate with, and be controlled by existing systems. 

The level of data collection depends on the degree of complexity of the application and the longterm plans for coordinated operations. The examples given start on the basis of a complex 

application. The inventory may be less extensive for simpler applications. However, it is better to 

collect as much information as practical the first time, because requirements often change as 

systems are developed. A second trip to collect additional information is time consuming, so 

erring on the side of an excess of information is often a wise investment of time. 

Performing an inventory of freeway and arterial data collection systems, traffic control systems, 

information dissemination systems, and communications networks is best accomplished with an 

inventory system that is a combination of a database, configuration management software, and 

geographic information systems (GIS). It is recommended that data input to the inventory system 

makes use of a form for every piece of equipment inventoried. The inventory of communications 

networks should focus on collecting information about the types of wireline and wireless 

networks that are in place, their functions, their available capacity, and their transmission modes 

to define the ability for future devices to communicate on existing networks, the need for 

additional capacity on existing systems for future devices, or the need for new communication 

systems altogether for future devices. 

Completing the inventory for field devices, such as detectors, surveillance cameras, RWIS, ramp 

meters, traffic signals, DMS, and HAR, will require significant time to complete, particularly for 

systems with significant amounts of deployment with few records of the existing systems. 

Performing the inventory for central systems, however, should not require as much effort. It will 

only require the information recorder to gather information about individual systems, such as 

parking management systems, motorist call-in systems, reversible HOV lane systems, and central 

data analysis systems, at a few locations. 

Ultimately, after populating the inventory system, it will enable a user to: 

 View the location of a selected type of system on a map. 

 View all systems for a selected area or route on a map. 
136

 View system owning and controlling agency information in list or map format. 

 Review quantities and locations of detectors, traffic control systems, and information 

dissemination systems by type, brand, model number, and/or information input/output in list 

or map format. 

 Review system communications networks information including wireline cable types and 

locations, wireless device types and locations, and associated field and hub communications 

equipment types, brands, models, and locations in list or map format. 

 Review system interconnections on a network diagram. 

Although the inventory system described above is the most comprehensive and useful for 

assessments, it is rather time-consuming and costly to populate and maintain. Agencies 

constrained by limited staffing and budgets may only be able to accomplish an inventory that 

makes use of manual formats or only involves necessary data input without a GIS map. 

Performing the inventory for data analysis systems and communications systems is drastically 

different from that described above because these systems consist of algorithms, firmware, 

central software, and integration of systems that enable processing, transmission, and receipt of 

information for CFA operations. These systems may reside in the field or at control centers. 

Because there are multitudes of data analysis systems and communications systems that can 

comprise CFA operations, it is advisable in performing an inventory to first consider all the 

concepts of operations that were envisioned and then outline the data analysis systems and 

communications required between control centers to achieve each operations concept. An 

example data analysis system and communication system inventory process for a coordinated 

ramp metering concept of operations follows. 

Ramp Metering Data Analysis System 

Does your data analysis system analyze the following to determine the best metering rates? 

 Freeway on-ramp detector data (stop bar, queue, and queue spill back). 

 Adjacent freeway detector mainline data. 

 Upstream freeway detector mainline data. 

 Downstream freeway detector mainline data. 

 Midblock arterial detector data. 

 Arterial detector data at traffic signal controlled intersections. 

 Traffic signal system control data and associated arterial volumes to anticipate queue spillback 

from the ramp into the intersection. 

Is the detector and control system data received often enough? Are you analyzing the most 

appropriate types of data (i.e., should you receive and analyze speed, occupancy, and volume data 

instead of only receiving speed data?)? 

Ramp Metering Communication System 

Can control center operators of the ramp meter owning/controlling agency: 

 Observe and adjust ramp metering rates via the central control system? 
137

 Observe traffic conditions at the ramp meter through a surveillance camera at the control 

center? 

 Observe the traffic data elements listed for the ramp metering data analysis system in tabular 

or map format? 

Can the traffic signal control owning/controlling agency and other jurisdictions perform the functions 

listed above for the ramp meter owning/controlling agency? Can the agencies control the traffic signal 

operations to give less green-time to phases that send vehicle platoons to the freeway ramp when the 

ramp is at capacity? 

Interagency Freeway and Arterial ITS Infrastructure Needs 

Following completion of the inventory of all infrastructure elements, agencies must determine 

whether they can accomplish their concept of operations for each coordination management 

operations plan through the existing infrastructure for all desired areas of a corridor. Agencies 

should consider traffic data collection systems, traffic control systems, information dissemination 

systems, communications networks, data analysis systems, and communications systems that can 

be deployed to better CFA operations. If the infrastructure is insufficient, agencies should use 

the inventory to identify which locations require further infrastructure deployment. 

Performing an Infrastructure Needs Assessment 

When an agency that operates and maintains arterials performs a needs assessment, they should 

consider deployment needs on their own road networks and on the freeway networks that will 

enable the agency to improve operations on their own system via coordination with the freeway. 

Conversely, an agency that operates and maintains freeways should consider deployment needs 

on the freeways and on adjacent arterials to improve operations on their own system through 

coordination with the arterials. Freeway and arterial agencies should work together to complete a 

needs assessment, particularly when the agencies have a specific coordination applications goal, 

such as planned special event management coordination. The first recommended step is for each 

agency to independently answer the needs assessment questions. 

The next step is for the agencies to meet to discuss their identified needs and prioritize 

deployment needs for achieving the coordination goal. The following questions address the 

process of needs assessment: 

 Do you need to replace existing or deploy additional traffic data collection systems for your 

coordination application? 

 Do you need to replace existing or deploy additional traffic control systems for your 

coordination application? 

 Do you need to replace existing or deploy additional information dissemination systems for 

your coordination application? 

 Do you need to replace existing or deploy additional communications networks for your 

coordination application? 

 Do you need to replace existing or deploy additional data analysis systems for your 

coordination application? 
138

 Do you need to replace existing or deploy additional communications systems for your 

coordination application? 

Specific Infrastructure Needs Assessment Questions 

Additional example infrastructure needs assessment questions for specific deployment on 

freeways and arterials, specifically for recurring and nonrecurring congestions, are included in 

the following sections. 

Freeway System 

Recurrent Congestion Infrastructure Needs 

 If providing coordinated and seamless motorist information is an objective of the concept of 

operations, are the existing detection sources, locations and types sufficient to provide speed, 

congestion, volume, and/or traveltime information on all controlled access facilities within the 

region? An example may be to consider probe-based surveillance (transponders or cell phone 

users) technologies to better determine traveltimes in lieu of using algorithms to approximate 

this information. 

 Is there additional information needed from the system, such as vehicle classification 

information, or is there a need to introduce ramp metering (Note: Ramp metering might be 

needed to address recurrent congestion or needed on a temporary basis to encourage diversion 

to parallel arterials during a major construction on the controlled access facility) that requires 

additional deployment of sensors? 

 Is there any additional detection needed at the intersection of freeway exit ramps and major 

arterials? An example of this would be a point where an exit ramp may be backed up from the 

intersection. In this case, it might be beneficial to install a sensor on the exit ramp to determine 

at what volumes this backup occurs and then to allow proactive changes in the signal timing at 

the downstream intersection. 

 Are there fixed time ramp metering operations that are negatively affecting arterial operations? 

If so, do you want to upgrade the ramp metering operations from fixed time to real time and 

therefore need additional detection installations? 

 Is there any gap in surveillance coverage along controlled access facilities? 

Nonrecurrent Congestion Infrastructure Needs 

 While ramp metering might not be needed or feasible, it may be worthwhile to install sensors 

on entrance and exit ramps in preparation for construction and maintenance zones, incidents, 

and special events. 

 Are there any gaps in surveillance coverage along controlled access facilities that might be 

needed on a short-term basis because of an upcoming special event or construction and 

maintenance zone operation? 

 Is there a need to install lane control signals? 

 Does an automated incident recording system exist that would allow information to be 

automatically shared with other agencies? 
139

 Are certain controlled access facilities to be used as preplanned alternative routes? If so, would 

it be beneficial to install remote controlled static guide signing to be used real time during 

major incidents and provide improved motorist information? 

 Should additional DMS and HAR be installed to provide better motorist information for 

special event venues? 

Arterial Network 

Recurrent Congestion Infrastructure Needs 

 If providing coordinated and seamless motorist information is an objective of the concept of 

operations, are the existing detection sources, locations, and types sufficient to provide speed, 

congestion, volume and/or traveltime information on all controlled access facilities within the 

region? An example may be to consider probe-based surveillance (transponders or cell phone 

users) technologies to better determine traveltimes in lieu of using algorithms to approximate 

this information. The installation of permanent traffic recording stations might be beneficial on 

major arterials to better determine periods of capacity or over-saturated conditions. This is 

especially true if the installation of CCTV devices is not feasible. 

 Are all intersections along primary alternative routes to freeways actuated? 

 Is there some form of automated surveillance at critical intersections along primary alternative 

routes to freeways? 

 Is it possible to install dynamic signing at major intersections to change geometrics on a realtime basis? 

 Is there a computerized traffic signal installed on the primary alternative routes to freeways? 

Nonrecurrent Congestion Infrastructure Needs 

 Are temporary detectors needed to collect speeds, volumes, occupancy, density, congestion 

queuing, traveltimes as a traffic mitigation measure during major construction and 

maintenance zone operations or for special events? 

 To manage traffic during major construction and maintenance zone operations, it might be 

beneficial to install temporary traffic recording stations on parallel arterials to better determine 

unexpected periods of capacity or oversaturated conditions. This is especially true if the 

installation of CCTV devices is not feasible. 

 Is there a need to install traffic counting sensors at major parking facilities? 

 Is there a need to install additional detection to allow the interconnection of a train grade 

crossing into a traffic signal system to move traffic across the grade crossing in advance of the 

train approach and only allow traffic movements that do not go toward the grade crossing 

while train is crossing? 

 Are certain surface streets to be used as preplanned alternative routes? If so, would it be 

beneficial to install remote controlled static guide signing to be used real time during major 

incidents and provide improved motorist information? 

 Can DMS and HAR be installed to provide better motorist information for special event 

venues? 

 Does an automated incident recording system exist that would allow information to be 

automatically shared with other agencies? Do other municipal agencies such as public works 

departments and utilities have access to this system? 
140

Prioritizing Infrastructure Deployment 

In most circumstances, budgetary constraints will be a 

significant factor in making deployment decisions; 

therefore, agencies should consider all of their 

deployment needs and associated cost estimates to 

develop a prioritized deployment list. To develop a 

complete list of deployment needs, agencies should 

answer questions similar to those above and complete infrastructure needs forms for each 

concept of operations they generated for every type of CFA operations application. They can 

then compare this information to determine which deployment efforts will enable accomplishing 

multiple goals and to prioritize deployment based on cost effectiveness, immediate needs, and 

ability to bring systems online. Consider this example. It is determined that 2 ramp meters, 9 

ramp detectors, 56 arterial midblock detectors, and 4 CCTV cameras should be deployed for 

ramp metering efforts for day-to-day management coordination and traffic incident management 

coordination. CCTV cameras and detectors are also desired for upcoming planned special event 

management coordination within the same area. If sufficient funds are not available to deploy all 

of the technologies in this case, the best choice is to implement only the surveillance cameras 

and some detectors first. If agencies are focusing on a particular CFA operations application, 

they may want to perform only a needs assessment for that application. 

In comparing desired uses of an existing communications network, agencies can determine 

whether deployments will exceed available capacities, and if so, they will need to prioritize 

deployment or add capacity to the network. 

Another issue that must be considered in assessing deployment needs is the level of compatibility 

between disparate communication systems. If various agencies operate and maintain 

technologies that are incompatible, agencies should develop a comprehensive plan to trade out 

equipment or integrate systems to enable CFA operations. Future deployments must use 

technologies that apply national ITS standards to enable future systems integration as legacy 

systems are replaced. 

Integration of Interagency Systems 

Stakeholders identify and document information they want to share between their field devices 

and control center systems in a concept of operations document and in accordance with their 

regional architecture. They must then assess the compatibility and available capacity of existing 

control center systems, field devices, and communications systems to assess the best means of 

integrating their systems. 

Although the control center system integration assessment will make use of the data analysis and 

communications systems inventory, it will also involve a detailed assessment of all system 

components within each center. This includes individual data elements employed in system 

software, software code, the ability to modify software elements and modules, control center 

equipment protocols and configurations, video and data networks, control system capabilities, 

and workstation features. The selection of appropriate systems integration between control 

Future deployments should use 

technologies that apply national ITS 

standards to enable future systems 

integration as legacy systems are replaced. 
141

centers must incorporate ITS standards, including center-to-center and traffic management data 

dictionary. 

The field device and communications systems assessment will make use of the traffic data 

collection systems, traffic control systems, information dissemination systems, and 

communications network technology inventories. Stakeholders will need to review the features 

of field devices, such as data inputs and outputs, protocols, standards, and means of 

communications to assess interfacing abilities directly from the field and via control centers. The 

communications systems assessment will involve reviewing the location of existing wireline and 

wireless networks and their available capacities, system protocols, and networking parameters to 

determine whether the existing communications systems can support the desired systems 

integration. 

Following these assessments, the final step will be to develop a deployment and migration plan 

for deploying communications network components, replacing field devices, updating system 

firmware, updating existing control center system settings, deploying control center systems, 

developing new software modules, writing software code to deploy standards, and bringing the 

integrated systems online to enable CFA operations. 

Systems Coordination for Traveler Information Dissemination 

While electronics can deliver information from the field to the control center and send it back out 

to the drivers, the information by itself is of little use without coordination among the many 

stakeholders. ITS and other electronic systems can play a significant role in this area. Part of the 

coordination challenge is making sure all the stakeholders get the information they need when 

they need it. So much information can be gathered that it must be put in context to be of use. 

This can be accomplished through filtering systems that make certain only the information 

needed is provided to each individual agency. 

Timeliness is also a critical part of systems coordination. Information should be delivered to all 

stakeholders simultaneously and as soon as it is verified. If one agency is operating with out-ofdate information, they may be taking actions out of sync with 

other stakeholders. Timeliness is also critical to the largest 

stakeholder group, the traveling public. If information is old 

and no longer accurate, the value of the system is not only 

diminished during the incident in question, but for future 

incidents as well. An example might be information displayed 

by one agency on a DMS that conflicts with information being broadcast on another agency’s 

HAR system. 

Accuracy is a third important piece of systems coordination. Control centers need to be able to 

give stakeholders 100 percent accurate information, even if that information is not 100 percent 

complete. For example, the control center may know there is a slowdown eastbound at milepost 

28.3 without knowing the reason for the slowdown. It must be certain not only that it delivers the 

information, but that it is understood. ITS can play a role here by providing the information in a 

consistent, easily understood format, by taking additional steps such as plotting the location on a 

map and by automatically identifying the surveillance tools that can monitor the incident. 

Part of the coordination challenge 

is making sure all the stakeholders 

get the information they need when 

they need it. 
142

Effectively providing traveler information across agency jurisdictional boundaries within a 

region requires the integration of the above data to traffic control centers and center-to-center 

linkages. It is encouraged that a region develops a regional architecture to facilitate the 

implementation of these system and data interfaces. The result will be a traveler information 

center/system (virtual or staffed) that disseminates information via: 

 Web (fully automated). 

 Phone call-in system / 511 (fully or partially automated). 

 DMS. 

 HAR or other radio means (fully or partially automated or manual). 

 Flashing beacons with static sign descriptor alerting motorists to tune in (fully or partially 

automated or manual). 

 Lane control systems. 

Communication is needed with the media to support information sharing with stakeholders. 

Therefore, data and video links to the media may be required. This would allow the media to 

provide coordinated and accurate information, such as recommending alternate routes around 

congestion. 
143

REFERENCES 

1. Meyer, M.D, A Toolbox for Alleviating Traffic Congestion and Enhancing Mobility,

Institute of Transportation Engineers. (Washington, DC: 1997). 

2. Cambridge Systematics, Inc. with Texas Transportation Institute, “Traffic Congestion 

and Reliability: Trends and Advanced Strategies for Congestion Mitigation,” Federal 

Highway Administration (Washington, DC: September 2005). 

3. Federal Highway Administration, “Operations Story: About Us,” (Washington, DC: 

August 2005) http://www.ops.fhwa.dot.gov/aboutus/opstory.htm. 

4. Federal Highway Administration, Intelligent Transportation Infrastructure Benefits: 

Expected and Experience, FHWA Report No. JPO-96-008 (Washington, DC: 1996). 

5. Diakaki, C, Papageorgiou, M., and McLean, T., “Application and Evaluation of the 

Integrated Traffic-Responsive Urban Corridor Control Strategy (IN-TUC) in Glasgow,” 

Transportation Research Record, No. 1727, Transportation Research Board, 

(Washington, DC: 2000). 

6. Logi, F. and Ritchie, S.G., “Development and Evaluation of a Knowledge-Based System 

for Traffic Congestion Management and Control,” 79th Transportation Research Board 

Annual Meeting Compendium of Papers. Volume 9C, No. 6, pp. 443–459, December 

2001. (Washington, DC: 2000). 

7. Carter, M. (primary), Cluett, C., DeBlasio, A., Dion, F., Hicks, B., Lappin, J., Novak, D., 

Rakha, H., Riley, J., St-Onge, C., and Van Aerde, M., Metropolitan Model Deployment 

Initiative: San Antonio Evaluation Report (Final Draft), U.S. Department of 

Transportation, FHWA-OP-00-017 (Washington, DC: May 2000). 

8. Wunderlich, K. and Larkin, J., “Impacts of Supplementing Web-Based Urban Freeway 

ATIS With Parallel Arterial Travel-Time Data,” Presented at the 7th World Congress 

Conference on ITS, Turin, Italy, November 2000. 

9. Briggs, V., and Jasper, K., Organizing for Regional Transportation Operations: An 

Executive Guide, Report No. FHWA-OP-01-137, Institute for Transportation Engineers, 

Federal Highway Administration, (Washington, DC: August 2001). 

10. Maricopa Association of Governments, MAG Regional Concept of Transportation 

Operations, Guidelines for Regional Transportation Operations, (Phoenix, AZ: 2004) in 

consultation with Kimley-Horn and Associates, Inc. 

11. Federal Highway Administration, Regional Transportation Operations Collaboration 

and Coordination: A Primer for Working Together to Improve Transportation Safety, 

Reliability, and Security, Report No. FHWA-OP-03-008 (Washington, DC: December 

2002). http://www.itsdocs.fhwa.dot.gov//JPODOCS/REPTS_TE//13686.html 

12. Smith, B., Developing and Using a Concept of Operations in Transportation 

Management Systems, Final Report. Federal Highway Administration, Transportation 

Management Center Pooled Fund Study, (Washington, DC: 2004). 

13. Dunn, W., Reiss, R., and Latoski, S., NCHRP Synthesis of Highway Practice 279, 

Roadway Incident Diversion Practices, Transportation Research Board, National 

Research Council (Washington, DC: 1999). 

14. DKS Associates in Cooperation with Oregon Department of Transportation and the City 

of Portland, OR., I-5/Barbur Boulevard Incident Management Operational Plan, User’s 

Manual, Version 1.0. October 2002. 
144

15. Williams, K., NCHRP Synthesis of Highway Practice 337, Cooperative Agreements for 

Corridor Management, Transportation Research Board, National Research Council 

(Washington, DC: 2000). 

16. Jacobson, L., Stribiak, J., Nelson, L., and Sallman, D., Ramp Management and Control 

Handbook, Federal Highway Administration, Report No. FHWA-HOP-06-001 

(Washington, DC: 2006). 

17. Mannering, F., Hallenbeck, M., Koehne, J., and Nee., J., Framework for Developing 

Incident Management Systems–Revised, Washington State Department of Transportation 

(Olympia, WA: October 1995). 

18. PB Farradyne., Traffic Incident Management Handbook, Federal Highway 

Administration, Office of Travel Management, (Washington, DC: November 2000). 

19. U.S. Department of Transportation, Regional Traffic Incident Management Programs, 

Implementation Guide, Report No. FHWA-OP-01-002 and FTA-TRI-11-00-03, Federal 

Highway Administration and Federal Transit Administration, (Washington, DC: 

May 2001). 

20. Neudorf, L., Randall, J., Reiss R., and Gordon, R., Freeway Management and Operations 

Handbook, Report No. FHWA-OP-04-003, Federal Highway Administration,

(Washington, DC: September 2003).

21. Federal Highway Administration, Traffic Incident Management Self-Guide,

(March 2004). Accessed at: http://www.ops.fhwa.dot.gov/incidentmgmt/index.htm. 

22. Briggs, V. and Jasper, K., Organizing for Regional Transportation Operations: New 

York/New Jersey/Connecticut TRANSCOM, Federal Highway Administration, 

(Washington, DC: August 2001). 

23. Manual on Uniform Traffic Control Devices (MUTCD), Federal Highway 

Administration, (Washington, DC: 2003). 

24. Federal Highway Administration, Work Zone Mobility and Safety Self-Assessment Guide, 

(May 2004). Accessed at http://ops.fhwa.dot.gov/wz/docs/wz-sa-docs/sa_guide_s1.htm. 

25. Latoski, S., Dunn, W., Wagenblast, B., Randall, J, and Walker, M., Managing Travel for 

Planned Special Events, Office of Transportation Management, Federal Highway 

Administration, (Washington, DC: September 2003). 

26. Humphreys, D.W., The Application of Vision Based Tracking Sensors to Traffic Control 

Systems, Institute of Transportation Engineer, ITE Publication 78-443, 1978. 

27. Federal Highway Administration, Traffic Detector Handbook, Report No. FHWA-HRT06-108, (Washington, DC, in press May 2006).