A 2003 Simulation for Seattle

Benefits and

Costs of Full

Operations

and ITS

Deployment
Notice

The Federal Highway Administration 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 improvements.
1

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Evaluation Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Seattle’s Full Operations and ITS Deployment Scenario . . . . . . . . . . . . . . . . . . . . . .6

Benefits of Full Operations and ITS Deployment . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Costs of Full Operations and ITS Deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Technical Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Figures

Figure 1. Reduction in Hours of Delay Due to Operations and ITS Deployments . . . . .11

Figure 2. Proportion of Benefits in Seattle, by Time of Day . . . . . . . . . . . . . . . . . . .13

Figure 3. Proportion of Total Trips in Seattle, by Time of Day . . . . . . . . . . . . . . . . .13

Figure A-1. IDAS Analysis Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Tables

Table 1. Strategies Included in the Seattle Full Operations and ITS Deployment Scenario . . .7

Table 2. Comparison of Recurring Delay Reduction for Various Roadways, 

by Time of Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Table 3. Annual Benefits of Operations and ITS Deployment in Seattle . . . . . . . . . . .12

Table 4. Annual Cost of Operations and ITS Deployment for Seattle . . . . . . . . . . . .14

Table 5. Comparison of Annual Benefits and Costs in Seattle . . . . . . . . . . . . . . . . .15

Table A-1. Cincinnati Analysis Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Table A-2. Capacity Reductions Used to Represent Inclement Weather Conditions . . .26

Table A-3. Impacts of Weather and Work Zone Mitigation Strategies . . . . . . . . . . .28

Table A-4. Annualization Weights for Cincinnati . . . . . . . . . . . . . . . . . . . . . . . . . .29

Table of Contents
2

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Preface

People who live in urban areas nationwide

report that traffic congestion is one of their

greatest quality-of-life concerns. When the

demand for travel in a region exceeds the

available capacity of the transportation

system, residents suffer from excessive travel

times, increased crash risks, diminished air

quality, and other negative impacts. State

and local transportation agencies have

found it difficult to increase the transportation

system supply rapidly enough to keep pace

with the growing demand. Traditional

approaches such as adding highway lanes,

building new roads, or providing new transit

lines are often too costly to be considered

as reasonable solutions, particularly in the

more densely populated areas of major

cities. Transportation agencies are further

challenged by the time required to design

and construct these traditional infrastructure

improvements. 

In response to this dilemma, transportation

agencies have increasingly turned to improved

operational strategies and Intelligent

Transportation Systems (ITS) in order to

squeeze more operational efficiency out of

the existing transportation system. Examples

of these operations and ITS strategies

include synchronizing the timing of traffic

signals to smooth traffic flow, providing

incident response vehicles such as freeway

service patrols to quickly clear traffic incidents

and breakdowns, automatically tracking

and dispatching transit buses to improve

their on-time performance, and providing

meaningful traveler information to the public

to allow travelers to better plan their trips.

ITS America, the professional organization

founded to facilitate the successful deployment

of such systems, defines ITS as follows:

“Intelligent transportation systems encompass

a broad range of wireless and wireline

communications-based information, control

and electronics technologies. When

integrated into the transportation system

infrastructure, and in vehicles themselves,

these technologies help monitor and

manage traffic flow, reduce congestion,

provide alternate routes to travelers,

enhance productivity, and save lives,

time, and money.”1

Information technology has contributed to

efficiency gains in a wide range of industries,

and ITS produces similar results for transportation. ITS solutions can be implemented

more quickly and less expensively in

comparison to traditional infrastructure

improvements, and nationwide deployments

of ITS have been shown to produce

significant benefits. By themselves, these

operations and ITS strategies will not

eradicate congestion; however, they are

essential components to a well-balanced,

well-operating transportation network. 

Furthermore, these individual operations

and ITS improvements can be tied

together to achieve even greater benefit

than they can alone. Recognizing that

the whole is often greater than the sum

of its parts, the United States Department

of Transportation (U.S. DOT) and numerous

local agencies have launched initiatives

to encourage deployment and integration

of these systems in order to maximize

their potential benefits. 

1 ITS America website: www.itsa.org.
3

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

The goal of full deployment and complete

integration of ITS, however, has yet to be

realized in any metropolitan area. Financial

constraints, along with technical and

institutional barriers, have held up achievement of this goal. Operations and ITS

implementation have typically advanced

incrementally within communities, targeting

the highest priorities first while deferring

enhancements until additional resources

are available. This piecemeal approach

has hindered or sometimes prevented the

integration of the individual deployments,

excluding regions from experiencing the

full potential of benefits from a coordinated

and complementary system.

To date, the analysis and evaluation of

operations and ITS deployments have

followed a similar path—often focusing on

the benefits of a single ITS technology

used in a single location. As a result of this

narrow focus, very little information exists

that exemplifies the benefits of increased

deployment and integration of operations

and ITS strategies. 

As a result, the Federal Highway

Administration (FHWA) initiated a study 

to explore the benefits and costs of fully

deploying operational strategies and

integrating ITS in metropolitan areas. The

goal of this effort is to provide transportation professionals and decision makers

with a better understanding of the potential

benefits of implementing the full suite of

available operations and ITS strategies in

a metropolitan area.

The U.S. DOT and FHWA selected

Tucson, Cincinnati, and Seattle for case

studies representing small, medium, and

large metropolitan areas, respectively.

Scenarios were identified comprising

complete operations and ITS deployment

at an appropriate, logical scale for each

area. These scenarios were then

evaluated to estimate the regionwide

benefits and costs. 

Beyond the difference in the size of the

three metropolitan areas, some additional

variations in the analysis approach affected

the relative benefits estimated in each case

study area. Benefits were estimated in the

Tucson example based on forecasts of

traffic in the year 2025, while the benefits

for Cincinnati and Seattle were based on

more current (2003) traffic conditions. The

Cincinnati study also includes the additional

analysis of impacts during inclement weather

conditions and construction activity, as

well as the added benefits of weather and

work zone mitigation strategies—strategies

that are not included in the deployments

for Tucson or Seattle. 

This report presents the findings of the

Seattle, Washington, scenario. The findings

of the Tucson scenario are presented in

Benefits and Costs of Full Operations and

ITS Deployment: A 2025 Forecast for

Tucson (FHWA-JPO-04-032, EDL#

13978). The findings of the Cincinnati

scenario are presented in Benefits and

Costs of Full Operations and ITS

Deployment: A 2003 Simulation for

Cincinnati (FHWA-JPO-04-031, EDL#

13979).
4

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

The analysis compares the

Full Operations and ITS

Deployment Scenario to 

one that contains no

operations and ITS

deployment whatsoever. 

How Were Operations and ITS

Strategies Selected?

Before estimating the potential benefits

and costs of the full operations and ITS

deployment in Seattle, it was first necessary

to identify the suite of ITS improvements

that would constitute “full deployment.” 

The process of identifying the logical

improvements to include in the full deployment started by conducting an inventory of

Seattle’s current and planned operations

and ITS deployments. The deployments in

this inventory then served as the building

blocks for the full deployment scenario.

These existing elements were then enhanced

and expanded by identifying additional

improvements to fill gaps, upgrade the

existing systems with more advanced

technologies, and then integrate the diverse

systems. The result was the establishment of

the Full Operations and ITS Deployment

Scenario, defined as the maximum amount

of locally desirable operations and ITS—at

the highest range of technical and institutional

sophistication—that can be deployed

without regard to funding constraints. 

Several additional guidelines were used 

in identifying the appropriate amount of

operations and ITS to include in the full

deployment scenario in order to avoid

making overly optimistic assumptions about

benefits. For example, the Full Operations

and ITS Deployment Scenario includes 

only those strategies that are funded or

significantly subsidized by the public

sector. Private sector strategies, such as 

in-vehicle navigation or safety systems in

personal automobiles, or freight management systems used by commercial trucking

firms, were not considered. Although the

benefits of these systems are not included

in this analysis, they are expected to offer

significant benefits.

In addition, the Full Operations and ITS

Deployment Scenario did not include

technologies or approaches that have not

currently progressed past development

and testing, due to a general lack of

industry consensus on their potential costs,

benefits, and market penetration. New

operations and ITS strategies are emerging

constantly due to the ever-changing nature

of technology; however, those improvements

evaluated in this study include only wellestablished systems that are currently in

use throughout the nation. 

How Were the Benefits

Estimated?

The analysis of the benefits and costs for

the Full Operations and ITS Deployment

Scenario was conducted using the ITS

Deployment Analysis System (IDAS). The

IDAS tool is specifically designed to

estimate the benefits and costs of ITS

deployments based on observed, realworld costs and benefits. This analysis tool

was used to estimate benefits, including

changes in travel time, travel time reliability,

number and severity of crashes, vehicle

emissions, fuel use, and other important

measures. 

The analysis compares the Full Operations

and ITS Deployment Scenario to one that

Evaluation Approach
5

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

contains no operations and ITS deployment

whatsoever. This “all-or-nothing” approach

was used to compare the complete costs

and benefits of operations and ITS in

Seattle for the current year (2003). This

approach further allows the findings to be

applicable to other regions that may be at

different stages of operations and ITS

deployment. 

The benefits of the operations and ITS

strategies in Seattle were estimated

separately for an average morning

commute period, an evening commute

period, and the remainder of the day. The

results from each of these daily periods

were then expanded to represent the

benefits that would occur during the

entire year and were compared with the

annual costs. A Technical Appendix

accompanying this report provides

additional detail on the methodology

used in estimating the benefits and costs.
The strategies included in Seattle’s Full

Operations and ITS Deployment Scenario

were identified by first consulting with

local agencies to identify the overall ITS

program planned through the next 25

years. Local agencies, including the Puget

Sound Regional Council (PSRC) and the

Washington State Department of Transportation (WSDOT), assisted in the analysis

by identifying current levels of operations

and ITS deployment in the region and

supplying plans for geographic expansion

and enhancement in the future. The Seattle

region has a long history of successfully

implementing ITS and operations strategies.

These strategies have been applied to

improve the efficiency and safety of travel

for nearly all modes of travel in the region,

including automobile, commercial trucks,

and transit (bus, ferry, and rail). 

Planned operations and ITS improvements

identified in the region’s long-range plans

were brought forward to the current year

and added to the inventory of existing

strategies to provide a rational baseline for

building the Full Operations and ITS

Deployment Scenario. This robust baseline

was then analyzed to identify supplemental

strategies, expanded geographic coverage,

and upgrades to technology that would

serve to fully deploy and integrate the

strategies throughout the region. This suite

of identified strategies formed the region’s

Full Operations and ITS Deployment

Scenario. 

Table 1 presents the strategies selected

and the number of deployment locations

for Seattle. The proportional coverage on

the system is also presented to portray the

ITS deployment density level relative to the

entire system.

6

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Seattle’s Full Operations and ITS Deployment Scenario
7

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Strategy Deployment Coverage

Arterial Traffic Management Systems

Central Control Signal 2,760 intersections 100% of urban intersections

Coordination

Emergency Vehicle Signal 2,760 intersections 100% of urban intersections

Preemption

1,030 emergency vehicles 100% of emergency vehicles

Transit Vehicle Signal 830 intersections 30% of urban intersections

Priority

2,260 transit vehicles 100% fixed-route transit vehicles

Highway Advisory Radio 6 transceiver 4% of arterial miles covered

Dynamic Message Signs 30 locations Located on the approach to all

major automobile ferry terminals

Freeway Management Systems

Central Control Ramping 165 on-ramps 65% of on-ramps

Metering

Highway Advisory Radio 13 transceiver 70% of freeway miles

Dynamic Message Signs 85 locations 100% of freeway miles

Transit Management Systems

Fixed-Route Automated 2,260 transit vehicles 100% fixed-route transit vehicles

Scheduling and Automatic

Vehicle Location

Fixed-Route Security 2,260 transit vehicles 100% fixed-route transit vehicles

Systems 40 transit stations 100% of major transit transfer stations

and park-and-ride locations

Incident Management Systems

Incident Detection, 40 freeway service 100% of freeway and expressway miles

Verification, Response, patrol vehicles

and Management

Emergency Management Systems

Emergency Vehicle Control 1,030 emergency vehicles 100% of emergency vehicles

Service

Emergency Vehicle AVL 1,030 emergency vehicles 100% of emergency vehicles

Telemedicine 100 ambulances 100% ambulances

Electronic Payment Systems

Electronic Transit Fare 2,260 transit vehicles 100% of fixed-route transit vehicles

Payment

Traveler Information

Telephone- and Web- Regionwide 40% of market penetration

Based Traveler Information

System

Kiosk-Based Traveler 20 kiosks 100% of major transit transfer stations

Information

Table 1. Strategies Included in the Seattle Full Operations and ITS Deployment Scenario
8

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Strategy Deployment Coverage

Crash Prevention and Safety

Railroad Crossing 12 rail crossings 5% of major at-grade rail crossings

Monitoring Systems

Commercial Vehicle Operations

Weigh-in-Motion and Safety 2 check stations 100% of check stations

Information Exchange

Combination Screening 2 check stations 100% of check stations

and Clearance–Credentials

and Safety 60,000 equipped 40% market penetration

commercial vehicles

Supporting Deployments

Traffic Management Center One 100% of region

Transit Management Center One 100% of region

Emergency Management One 100% of region

Information Service One 100% of region

Provider Center

Traffic Surveillance– 1,520 locations 100% of freeway, expressway, and urban 

Closed Circuit Television arterial miles

Traffic Surveillance– 3,270 locations 100% of freeway and expressway miles

Loop Detectors 100% controlled signals

Table 1. Strategies Included in the Seattle Full Operations and ITS Deployment Scenario (Cont’d from page 7)
What Would Be the Benefits?

The performance of the Seattle

transportation system in the year 2003

was analyzed for two deployment

scenarios—No Operations and ITS

Deployment, and the Full Operations and

ITS Deployment Scenario. The results from

the two scenarios were then compared to

identify the incremental change due to the

inclusion of operational improvements and

ITS deployment. 

This analysis was completed for three

different time periods: the morning

commute period, the afternoon commute

period, and the remainder of the day.

Summing the benefits from the three

periods resulted in the daily benefit. These

daily benefits were then expanded to

identify the annual benefits. 

The analysis of the Full Operations and 

ITS Deployment Scenario showed positive

impacts on all performance measures

studied, including:

■ Decreased travel times

■ Increased vehicle speeds

■ Decreased delay

■ Decreased number and severity of

crashes

■ Decreased environmental impacts

(reduced emissions and fuel use).

The following sections discuss these

impacts in greater detail.

Decreased Travel Times

The full implementation of operations and

ITS strategies resulted in a significant

decrease in personal travel time in the

region. Personal travel times were reduced

by an average of more than 120,000

hours daily in the Seattle region. Although

this average daily reduction is relatively

small (a decrease of 3.7 percent) when

compared with the 3.2 million person

hours of total travel time in the region, this

impact amounts to nearly 30 million hours

of travel time saved per year, or an

average of more than eight hours saved

per resident in the region annually. The

analysis also revealed that the operations

and ITS strategies are more effective at

reducing travel times during the more

congested commute periods. For example,

travel times in the afternoon commute

period were reduced by 6.1 percent

while travel times in the less congested,

non-commute period decreased by less

than 0.5 percent. 

Additionally, transit riders in particular

were expected to experience even more

significant travel time improvements,

averaging more than six minutes per trip

during the afternoon commute, or an

approximate 24 percent decrease in their

average trip time.

Increased Vehicle Speeds

Overall vehicle speeds throughout Seattle’s

roadway network increased by less than 1

percent on a daily basis as a result of the

operations and ITS deployments; however,

use of the average regionwide impact

masks much more significant impacts that

were observed on individual roadways.

The majority of the speed increase was

observed on major facilities, including

freeways, expressways, and major arterials

that served as a focus of a number of the

ITS and operations improvements. These

speed increases were typically even greater

during the more congested commute

periods. For example, speeds on the

regional freeways increased by 1.3

9

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Benefits of Full Operations and ITS Deployment
percent, and speeds on major arterial

roadways increased by 2.4 percent

during the afternoon commute period. The

speed increases observed for selected

segments of major roadways, such as

Interstate 90 near Bellevue or Interstate 5

between Seattle and Tacoma, were even

more significant, ranging as high as 12

percent. Speed increases observed on

more minor local streets, which received

fewer improvements, and during less

congested non-commute hours were

generally insignificant. Consequently, the

overall network speed impact was

moderated by the less significant impact

on the local street system. 

Decreased Delay

The ITS and operations strategies were

shown to improve the transportation system

speeds and travel times, particularly during

the congested, delay-prone commute

hours. This performance impact resulted in

significantly reduced delay in the region.

This reduction included a decrease in the

delay due to typical, recurring congestion

as well as a decrease in the delay caused

by traffic incidents. Overall, operations

and ITS strategies reduced the amount of

delay caused by everyday, recurring

congestion for roadway users by 3.2

percent in the Seattle region. This

reduction amounts to approximately

10,700 vehicle hours of delay per day,

or nearly 2.7 million hours per year.

Consistent with the observed speed

changes, the reductions in delay were

greatest on primary roadways that

received the greatest concentration of ITS

and operations deployments. Further, the

decreases in delay were even more

substantial during the commute periods.

Table 2 shows how the reductions in

delay varied according to the type of

roadway and the time of day. 

In addition to the impacts on delay related

to everyday congestion, many operations

and ITS strategies are intended to

specifically reduce incident-related delay.

These strategies diminish incident-related

delay by either decreasing the number of

crashes occurring on the network, or

minimizing the time required to respond

and clear incidents once they do occur. In

the Seattle region, the full deployment of

operations and ITS resulted in a dramatic

reduction of incident-related delay. This

reduction, which was only estimated for

freeways, amounted to an average of

nearly 55,100 hours saved per day. 

This represents a decrease of more than

10

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Table 2. Comparison of Recurring Delay Reduction for Various Roadways, by Time of Day

Major Rest of

Freeways Arterials Network Total

Morning Commute Period -4.2% -4.8% -1.7% -3.7%

Afternoon Commute Period -4.5% -11.7% -2.8% -5.0%

Remainder of Day -0.5% -6.1% 0.0% -1.5%

Total -2.7% -7.5% -1.4% -3.2%
50 percent of the total freeway incidentrelated delay. Figure 1 shows the reduction

in hours of everyday recurring delay

compared with the reduction in hours of

incident-related delay on the freeways.

Similar to many of the other noted impacts,

the reduction in incident-related delay was

most significant during the more congested

commute periods. More than 63 percent

of the total incident-related delay reduction

was observed in the afternoon commute

time period, amounting to an average

savings of nearly two minutes per freeway

trip during this time. An additional 36

percent of the total reduction in incidentrelated delay was observed during the

morning commute hours, with the remaining

1 percent in reduction observed throughout

the remainder of the day. 

Decreased Number and Severity of

Crashes

By lessening congestion and smoothing

traffic flows, the operations and ITS

deployments resulted in the elimination of

more than seven crashes per day in the

Seattle region. Additionally, the deployment

of incident and emergency management

systems, which minimize the response time

to crashes, led to a reduction in the severity

of crashes as well. Overall, fatal crashes

decreased by more than 8 percent, while

injury and property damage crashes were

reduced by approximately 3 percent. Over

the course of a year, this safety improvement

resulted in the avoidance of approximately

20 fatal crashes, 770 injury crashes, and

1,050 property damage crashes per year

in the Seattle region.

Decreased Environmental Impacts

The operational and ITS improvements

resulted in decreased vehicle pollutants

and reduced fuel use in the Seattle region.

The full deployment of these strategies

resulted in a reduction for all emissions

analyzed. Carbon monoxide and

hydrocarbon emissions were reduced by

approximately 16 and 17 percent,

respectively, while nitrous oxides were

reduced by more than 21 percent. 

Fuel use in the region was cut by more

than 1 million gallons per day, a total

reduction of more than 19 percent. 

This represents an average savings of 

more than 0.1 gallons per trip.

11

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

0

150,000

100,000

50,000

200,000

250,000

300,000

350,000

400,000

450,000

Incident-Related Delay

No Operations 

and ITS Hours of Delay

Full Operations 

and ITS

Recurring Delay

Figure 1. Reduction in Hours of Delay Due to Operations 

and ITS Deployments

Note: Incident-related delay represents only the 

hours of delay on the regional freeways.
What Would Be the Value 

of the Benefits?

The monetary value of the benefits of 

Full Operations and ITS Deployment was

estimated by applying a dollar value to

each of the impacts. For example, the

estimated number of gallons of fuel saved

per day was multiplied by the number 

of days per year and by the cost of a

gallon of fuel. Similar computations 

were performed for the other observed

incremental impacts. When the impacts 

of the operations and ITS deployments

were annualized and dollar values

applied, the benefits total more than 

$1.6 billion per year for the Seattle

region, as presented in Table 3, along

with the percentage of the value of 

each benefit compared to the total.

A further comparison of the proportion 

of the benefits that were accrued in each

time period revealed that the majority of

benefits for the operations and ITS strategies

occurred during the peak afternoon (40

percent) and morning (25 percent) commute

periods, as shown in Figure 2. This

difference occurs despite the fact that

these peak commute periods are shorter 

in duration than the non-commute periods

and that the overall majority of trips are

spread out during these other times of the

day, as shown in Figure 3. This trend

suggests that operations and ITS strategies

are most effective at providing benefits

during these highly congested commute

periods when the transportation system 

is most likely to break down. 

12

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Table 3. Annual Benefits of Operations and ITS Deployment in Seattle (In $ Millions in 2003 dollars)

Benefits Value % of Total

Reduction in travel time (Mobility) $337 21%

Reduction in incident delay (Reliability) $502 31%

Reduction in crashes (Safety) $136 9%

Reduction in emissions (Environment) $181 11%

Reduction in fuel consumption (Energy) $409 25%

Increase in public agency efficiency (Productivity) $7 1%

Other2 $39 2%

Total benefits $1,610 100%

2 Other estimated benefits include reduced noise, decreased non-fuel operating costs, and

additional safety benefits associated with decreased emergency vehicle response time.
13

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Figure 2. Proportion of Benefits in Seattle, by Time of Day

Figure 3. Proportion of Total Trips in Seattle, by Time of Day

Off-Peak

35%

.M. Peak

41%

A.M. Peak

24%

Off-Peak

56%

.M. Peak

25%

A.M. Peak

19%
14

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

The average life-cycle costs of the

resources necessary to implement,

operate, and maintain the operations and

ITS in Seattle were estimated to be

$131.5 million annually. Table 4 presents

the costs for the Full Operations and ITS

Deployment Scenario.

Although the strategies included in this

analysis were primarily funded by the

public sector, a portion of the costs was

projected to be paid for by the private

sector. These private sector costs include

the equipment needed on commercial

trucks to enable the use of automated

screening and clearance deployments at

check stations. The considerable number

of commercial trucks assumed to be

equipped in the full deployment scenario

(60,000) influenced the substantial

estimated cost for this equipment. 

Supporting deployments presented in

Table 4 represent the backbone

infrastructure necessary to operate and

manage the deployed strategies. These

include items such as traffic management

centers, traffic surveillance cameras, and

communication systems. 

Costs of Full Operations and ITS Deployment

Table 4. Cost of Operations and ITS Deployment for Seattle

Deployment Cost Percentage 

of Total Costs

Arterial management systems $12.1 9.1%

Freeway management systems $7.0 5.3%

Transit management systems $8.9 6.8%

Incident management systems $7.7 5.9%

Emergency management systems $1.8 1.4%

Electronic payment systems $5.9 4.4%

Traveler information $2.4 1.8%

Crash prevention and safety $0.5 0.4%

Commercial vehicle operations $23.0 17.4%

Supporting deployments $62.9 47.6%

Total costs $132.1 100.0%

Private sector costs $22.4 17.0%

Public sector costs $109.7 83.0%
15

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

The benefits of the deployment

outweigh the costs by a ratio of

12.2 to 1.

How Do the Costs 

and Benefits Compare?

The annual estimated benefits compare

quite favorably to the costs, and the results

show the investment in operations and ITS

in Seattle to be cost-efficient. The benefits

of the deployment outweigh the costs by a

ratio of 12.2 to 1, as shown in Table 5.

This ratio indicates that each dollar spent

on operations and ITS in the Seattle region

would return $12.20 in benefits, including

decreased travel time, improved safety,

and a reduction in vehicle emissions and

fuel consumption.

The benefits estimated for the full

deployment of operations and ITS in

Seattle were overwhelmingly positive

when compared with the costs. The

conservative treatment of several factors

related to the analysis suggests that future

benefits of operations and ITS may be

even greater. These assumptions include:

■ The analysis only considered those

operations and ITS deployments that are

funded or significantly subsidized by the

public sector. Many additional private

sector ITS initiatives are currently

deployed or planned, but were not

considered in this analysis. These private

sector deployments, such as in-vehicle

navigation and safety systems, and

commercial vehicle tracking and

dispatching, would likely provide

benefits beyond those presented in this

report.

■ The analysis used currently observed

equipment costs as the basis for

estimating the expenditures necessary to

deploy and operate the strategies. The

level of deployment considered for many

strategies is beyond what has been

deployed in any region to date;

however, there may be significant

economies-of-scale cost savings that

would reduce the incremental cost of the

deployments, if they were deployed at

this scale. This impact was not

considered in this analysis since there is

currently little consensus on the precise

savings that might be achieved. This

assumption may result in the

overestimation of costs associated with

full deployment. 

Table 5. Comparison of Annual Benefits and Costs in Seattle (In $ Millions in 2003 Dollars)

Average annual benefits $1,160

Average annual costs $132

Benefit–cost ratio 12.2
16

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

The ability of the operations

and ITS strategies to provide

positive impacts was

estimated to be even more

substantial during congested

commute periods.

The potential benefits and costs of fully

deploying and integrating operations and

ITS strategies in the Seattle region were

examined in this analysis. A Full

Operations and ITS Deployment Scenario

was identified, representing the maximum

amount of locally desirable operations and

ITS. This Full Deployment Scenario was

compared to a scenario without any

operations and ITS deployments in order

to identify the incremental changes in

impacts that might be possible in the year

2003. The results showed the investment

in operations and ITS to be cost-efficient—

returning $12.20 in benefits for every

dollar invested. 

Operations and ITS strategies were shown

to have a positive impact in reducing

many of the negative impacts related to

congestion: delays, crashes, and

environmental impacts. The ability of the

operations and ITS strategies to provide

positive impacts was estimated to be even

more substantial during congested

commute periods. By reducing the amount

of time people spend stuck in congestion,

operations and ITS would also reduce the

frustration of travelers and likely have a

positive influence on regional productivity,

further contributing to improvements in the

quality of life in the Seattle region. 

The full deployment of operations and ITS

in Seattle was projected to produce

benefits that were overwhelmingly positive

when compared with the costs. The

conservative treatment of several factors

related to the analysis suggests that future

benefits of operations and ITS may be

even greater. 

For More Information

Additional information on the operations

and ITS strategies discussed in this report

can be obtained through the FHWA’s

Office of Operations ops.fhwa.gov and

through the U.S. Department of

Transportation’s ITS Joint Program Office

www.its.dot.gov. For additional

information on the individual benefits and

costs of the ITS deployments presented in

this report, please visit the ITS Joint

Program Office’s ITS Benefits and Costs

Database at www.benefitcost.its.dot.gov.

More information on the IDAS analysis

tool used in this evaluation may be 

found at idas.camsys.com. Please visit 

the ITS Deployment Tracking website,

www.itsdeployment.its.dot.gov, for more

information on the current and historical

levels of operations and ITS deployment 

in U.S. metropolitan areas.

Summary
Background

This Technical Appendix provides a general

overview of the methodology used in the

study of the potential benefits of fully

deploying operations and ITS strategies.

This study was initiated by the U.S. DOT

to explore the benefits and costs of

fully deploying and integrating ITS and

operations strategies in metropolitan areas.

Three test sites—Tucson, Arizona; Cincinnati,

Ohio; and Seattle, Washington—were

selected to represent small, medium,

and large metropolitan areas, respectively.

Hypothetical deployment scenarios were

developed to represent the full logical

deployment of operations and ITS strategies

in each area. These scenarios were then

evaluated to identify the likely benefits and

costs of the deployments. The goal of

this study was to provide transportation

professionals and decision makers with an

increased understanding of the potential

benefits possible through the full deployment

of ITS and operations strategies. 

The findings from these three case studies

are summarized in individual reports. This

appendix provides additional detail on the

similar approach used in all three regions

to estimate the likely benefits and costs of

full operations and ITS deployment. 

Methodology Overview

The goal of this analysis was to estimate the

likely benefits and costs resulting from the

full deployment and integration of ITS and

operations strategies in a region. For the

purpose of this study, ”full deployment” is

defined as the maximum amount of locally

desirable ITS and transportation operations

strategies—at the highest range of technical

and institutional sophistication—that can be

deployed without regard to funding

constraints. Consistent with this goal and

definition, full operations and ITS deployment

scenarios were identified for the three

case study regions. 

The analysis methodology used in this study

was developed to identify the incremental

benefits and costs of the strategies contained

in the full operations and ITS deployment

scenario. To identify these incremental

impacts, it was necessary to estimate

what travel conditions would be in the full

operations and ITS deployment scenario,

as compared with a scenario that did not

contain any operations and ITS deployments. This ”all-or-nothing” approach was

used to isolate the full costs and benefits

of the operations and ITS deployments. 

The FHWA’s ITS Deployment Analysis

System software was used in conjunction

with the locally validated travel demand

models for the three case study regions

to predict the traffic conditions that would

be likely in the two deployment scenarios—

the No Operations and ITS Deployment

Scenario and the Full Operations and

ITS Deployment Scenario. An overview of

the IDAS tool analysis process is provided

in a subsequent section. 

This analysis approach resulted in numerous

regional performance measures being

estimated for the two scenarios, such as

the person hours of travel, roadway speeds,

the number of crashes, and the gallons

of fuel used, among others. To identify

the incremental impact resulting from the

deployment of ITS, the performance

17

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Technical Appendix
measures from the Full Operations and

ITS Deployment Scenario were subtracted

from the identical performance measures for

the No Operations and ITS Deployment

Scenario. The difference between the

performance measures of the two

scenarios represented the incremental impact

caused by ITS during the day or time period

represented by the model data. The annual

impact was determined by multiplying the

daily incremental impact by the number of

days per year. 

For example, the Tucson case study used

a single daily model in the analysis. To

estimate the impact on any particular

performance measure, such as the number

of fatality crashes, the following approach

was used:

■ Annual Benefit = (Number of Fatality

Crashes Occurring in the No Operations

and ITS Deployment Scenario – Number

of Fatality Crashes Occurring in the Full

Operations and ITS Deployment

Scenario) * Number of Days Per Year

For those models having multiple time

periods represented within a day, separate

No Operations and ITS Deployment and

Full Operations and ITS Deployment

Scenarios were developed for each time

period. The performance measure for the

No Operations and ITS Deployment and

the Full Operations and ITS Deployment

Scenarios were then compared within each

time period to identify the incremental

impact. The incremental impacts from all

the available time periods summed up

the daily impact.A-1 This summed figure

was then multiplied by the number of days

per year to annualize the benefit. An

example of this approach for annualizing

the results for models with multiple time-ofday analysis is shown below:

Where:

■ AMNo = performance measure from

the AM Peak Period – No Operations

and ITS Deployment Scenario

■ AMFull = performance measure from

the AM Peak Period – Full Operations

and ITS Deployment Scenario

■ MDNo = performance measure from

the Mid-day Period – No Operations

and ITS Deployment Scenario

■ MDFull = performance measure from

the Mid-day Period – Full Operations

and ITS Deployment Scenario

■ PMNo = performance measure from

the PM Peak Period – No Operations

and ITS Deployment Scenario

■ PMFull = performance measure from

the PM Peak Period – Full Operations

and ITS Deployment Scenario

■ OPNo = performance measure from

the Off-Peak Period – No Operations

and ITS Deployment Scenario

18

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

A-1 The summing of the performance measures across all time periods was performed for all cumulative impacts. Non-cumulative

performance measures, such as vehicle speeds, were not summed. Instead, these performance measures were calculated

from the cumulative performance measures. For example, the estimate of daily speed was determined by summing the vehicle

miles traveled (VMT) for all periods and dividing by summed vehicle hours traveled (VHT) for all periods.

Annual

Benefit * Number of

Days Per Year

AMNo – AMFull

MDNo – MDFull

PMNo – PMFull

OPNo – OPFull

= ∑
■ OPFull = performance measure from

the Off-Peak Period – Full Operations

and ITS Deployment Scenario

The value of the annual benefit was then

determined by applying the appropriate

benefit values from the IDAS tool to the

incremental change in the performance

measures. The values from all the various

performance measures were summed to

determine the total annual benefit of all

operations and ITS strategies included in

the Full Operations and ITS Deployment

Scenario. This benefit value was compared

with the annual cost of the strategies to

present the benefit/cost ratio for the

included strategies. 

IDAS Overview

What is IDAS?

The IDAS software was developed by the

FHWA as a tool focused on analyzing the

specific impacts of ITS. IDAS operates as

a post-processor to travel demand models

used by metropolitan planning organizations

and by state departments of transportation

for transportation-planning purposes. IDAS is

intended to mimic and build upon the

results of these tools, and shares many of

the same analysis techniques and processes.

Although a sketch-planning tool, IDAS

implements the modal split and traffic

assignment steps associated with a

traditional planning model. These steps

are key to estimating the changes in modal,

route, and temporal decisions of travelers

resulting from ITS technologies.

IDAS was developed as a tool specifically

focused on analyzing the specific impacts

of ITS. IDAS was also designed to serve as

a repository of information on the impacts of

various types of ITS deployments and of the

costs associated with various types of ITS

equipment. The default ITS impacts and costs

used in the IDAS tool are based on the

observed experiences of deploying

agencies, as maintained in the U.S.

DOT’s ITS Benefits and Costs Database,

www.benefitcost.its.dot.gov. By offering

these capabilities, IDAS provides the ability

to critically analyze and compare different

ITS deployment strategies, prioritize the

deployments, and compare the benefits of

the ITS deployments with other improvements

to better integrate ITS with traditional

planning processes.

How Does IDAS Work?

The IDAS tool works by importing the

results from travel demand models in order

to recreate the validated regional network

structure and travel demand within IDAS.

The data are imported into IDAS using a

special internal input/output interface,

which is capable of reading and interpreting

ASCII text data files. These input data files

are created from data generated by the

regional travel demand models. The data

exchanged between the travel demand

model and IDAS include network data

regarding the characteristics of transportation

facilities in the region and travel demand

data, including the number of trips and

mode share of travel between different

zone pairs in the model. Depending on

the needs of the analysis and the format

of the available data, the user is typically

required to perform some data conversion

prior to import into IDAS. Once the data

are imported, they are stored in a database

accessible by the IDAS software and may

be viewed in a graphical output by the user. 19

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
Once the data input is complete, IDAS is

capable of operating independently of the

travel demand model. The IDAS user is then

able to create analysis alternatives by

selecting ITS components from a menu

of more than 60 ITS improvements, and

placing these on the desired location on

the network. The user then provides

additional information regarding their

deployment, such as the implementation

date and proposed operational strategies.

Once the analysis alternative has been

created, the IDAS software then modifies

the network or travel characteristics to

represent the likely impacts of the ITS

deployments placed on the network by

the user. These modifications are based on

real-world impacts observed in other

regions following their deployment of

similar ITS components, and may include

changes in link capacities or speeds,

zone-to-zone travel times, crash or emissions

rates, or other impacts specific to the ITS

component. The specific default impacts

associated with each of the various ITS

deployments are described in Appendix B

– IDAS Default Values of the IDAS User’s

Manual available on the IDAS software

website idas.camsys.com.

The IDAS model then uses analysis

techniques similar to the travel demand

models to analyze the impacts created by

the modifications to the alternative network

and travel characteristics. A traffic assignment routine is used to estimate the changes

in travel patterns caused by the modifications, and a mode shift routine is used

to estimate any travel mode changes. The

results of this analysis are revised link

volumes and speeds and mode shares.

IDAS conducts the same analysis procedures

on the unmodified, baseline network

(without ITS deployments) as well as the

modified alternative network (with ITS

deployments). These two scenarios are then

compared to identify the incremental

impact resulting from the ITS deployment. 

The changes in link volumes and speeds

and mode shares are then used by IDAS

in another series of analysis to calculate

changes in the travel time, the number of

crashes, the amount of emissions and

other impacts. Dollar values are then

applied by IDAS to these impacts to

provide an estimate of the benefits of

the ITS components deployed in the

alternative. 

In a separate process, the costs of the ITS

deployments are also estimated by IDAS.

The costs of the ITS deployments are

calculated by identifying the inventory

of equipment necessary to deploy and

operate each improvement, based on

the suggested equipment packages in

the ITS National Architecture. IDAS then

applies unit costs (capital and operations

and maintenance [O&M] costs) to each

piece of equipment in the inventory and

annualizes the capital costs based on the

anticipated useful life of the equipment.A-2

The costs of all equipment included in

the inventory for a particular deployment

alternative are summed and compared

with the benefits in the form of a benefit/

cost ratio. These outputs are summarized

and displayed to the user in several

formats. The complete IDAS analysis 20 process is summarized in Figure A-1.

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle A-2 IDAS equipment unit costs are periodically updated to represent the latest costs reflected in the U.S. DOT’s ITS Benefits and

Costs Database: www.benefitcost.its.dot.gov.
Additional information regarding the

structure of IDAS and its processes is

presented in the IDAS User’s Manual,

which is distributed electronically with the

IDAS software, or is available on the

IDAS website at idas.camsys.com.

Use of IDAS in Analyzing the Impacts

of Full Operations and ITS Deployment

Except where noted, the analysis of the

impacts of full operations and ITS deployment used the default IDAS procedures,

parameters, and impacts. These parameters

and impact values were held constant in

the three case study regions in order to

produce comparable results. 

The following exceptions to the standard

IDAS methodology were made in the

analysis:

■ Estimation of Costs – A separate cost

estimation spreadsheet tool was

developed outside the IDAS software to

calculate the cost of the operations and

ITS deployments. This spreadsheet tool

applied the same methodology and

used the identical equipment unit costs

as the IDAS software. This external

spreadsheet method was used to

improve the ease of use for the analysts,

and better account for particular ITS

equipment not currently represented in

the IDAS software.

■ Estimation of the Impacts of Advanced

Traveler Information Systems (ATIS) – 

A blanket assumption of the overall

effectiveness of all ATIS deployments

was made, rather than make individual

assumptions regarding the likely market

penetration and effectiveness of each

individual component. It was assumed that

the various deployed ATIS components

(pre-trip and in-route systems) were

successful in reaching 40 percent of

travelers. Of those travelers receiving

the information, 25 percent were able

to save 6.3 percent of their travel time.

This impact assumption was based on

a comparison of the various IDAS impact

assumption values for the individual

ATIS components. 

■ Estimation of Benefit/Cost – An external

spreadsheet tool was developed to

compare the benefits and costs for the

full deployment scenario. This separate

spreadsheet was needed in order to

aggregate the results from multiple IDAS

runs representing different time periods

21

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

1. Appropriate regional data are obtained 

from travel model

2. User formats output from travel model 

for input into IDAS

3. IDAS reads and interprets input data

4. User creates alternatives by deploying 

ITS on the network

5. IDAS modifies network/travel 

characteristics to represent ITS impacts

6. IDAS reassigns traffic and estimates 

mode shift caused by modifications to 

network/travel characteristics

7. IDAS uses new link volumes and speeds, and

mode shares to calculate changes in travel time,

accidents, emissions, and other impacts

8. IDAS assigns dollar values to the impacts, and

estimates the costs of the ITS deployments

9. User is able to view (benefit/cost comparison,

performance measures) and compare alternatives

Figure A-1. IDAS Analysis Process
(A.M., P.M., etc.). IDAS currently only

has the ability to compare benefits and

costs for a single time period. This

spreadsheet compiled the results from

multiple time-period scenarios into

combined daily and annual results. 

■ Estimation of the Impacts of Weather

and Work Zone Mitigation Strategies –

Weather and work zone mitigation

strategies are not currently available as

deployments within the IDAS software.

Special analysis techniques were

developed, using capabilities within

the IDAS software, to analyze the

impacts of these specific strategies.

These techniques are described in a

subsequent section. 

■ Estimation of the Incident-Related 

Delay on Freeway Facilities – The

IDAS software contains a default

methodology and parameters for

estimating the incident related delay for

freeway facilities. Although previous

IDAS studies conducted by numerous

agencies have served to vet these

impacts as reasonable representations

for individual deployments, this study

includes combinations and intensities of

deployment that exceed any that have

been tested using this methodology. It

was the opinion of an expert panel that

reviewed the preliminary results that the

initial estimates of the cumulative impact

to incident related delay overstated the

potential reduction. In order to ensure a

conservative estimation of benefits, a

sensitivity analysis was performed to

identify the default impact parameters

used in IDAS that were most likely to

result in an overestimation of benefits.

These parameters were modified and

the model analysis was re-run to

produce the more reserved final results.

Model Networks 

and Adjustments

Network and travel demand data from the

regional travel demand models formed the

basis of the analysis. These models varied

from region to region in their size and

complexity. Additionally, some adjustments

were necessary to modify the available

travel demand model data to match the

specific needs of the desired analysis.

This section summarizes the models used

in the three regions and describes the

necessary modifications to generate the

baseline data needed for the analysis. 

Tucson

The model data available for the Tucson

region represented daily travel conditions in

the year 2025. This model was developed

and maintained by the Pima Association of

Governments (PAG). The Tucson model

was the smallest of the models used in

the analysis, representing a daily total of

approximately 5.4 million person trips

traveling between 870 possible origins

and destinations. Three vehicle modes

were represented in the model, including:

Auto, Light Truck, and Heavy Truck. Two

public transit modes were represented;

however, both represented bus travel. The

transit modes were differentiated by the

form of access to the transit stop: Transit

Walk Access and Transit Drive Access. 

No significant modifications were required

to prepare the Tucson model data for use

in the analysis. Minor reformatting of the

data was performed to prepare the data

for input into the IDAS software tool. 

Cincinnati

The Cincinnati region model, obtained

from the Ohio-Kentucky-Indiana Regional

Council of Governments (OKI), was the

most complex of the three regional models

used in the analysis. The model had

22

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
recently undergone a significant update,

which resulted in the merging of the

regional travel demand models

representing the Cincinnati and Dayton,

Ohio, regions. Models were specifically

developed for this analysis representing

travel demand for the year 2003. These

models were developed to represent four

separate time periods: A.M. Peak Period

(2.5 hours), Mid-day Peak Period (6.5

hours), P.M. Peak Period (3.5 hours), and

Off-Peak Period (11.5 hours). The

combined travel demand in these four

periods represented approximately 9.3

million daily person trips traveling between

2,999 possible origins and destinations.

Approximately 69 percent of this travel

occurs in the Cincinnati region. 

Adding to the complexity of the Cincinnati

model was the disaggregation of travel

into 11 possible modes, including five

vehicle modes: Single Occupancy Vehicle,

High Occupancy Vehicle (two people),

High Occupancy Vehicle (three or more

people), Single-Unit Truck, and MultipleUnit Truck. Six separate bus transit modes

were also available, segmented by the

type of bus service and access mode,

including: Local Bus Walk Access, Local

Bus Park & Ride, Local Bus Kiss & Ride,

Express Bus Walk Access, Express Bus

Park & Ride, and Express Bus Kiss & Ride. 

Several significant modifications were

made to the existing Cincinnati models to

prepare the data for use in this analysis.

The first modification was the development

of models representing travel in the year

2003. No specific existing models were

available representing this year. Travel

demand from models representing the

year 2000 and 2010 were interpolated

to develop travel demand trip tables for

each of the analysis periods representing

the year 2003. The model networks from

the 2000 models were used since these

models already contained roadway

improvements that were expected to be

completed by 2003. 

A second modification was required to

allow the analysis to focus only on the

impacts in the Cincinnati region. The

recent model update had merged the

previous models from the Cincinnati and

Dayton regions into a single model;

however, the focus of this analysis was

only on the Cincinnati region. A special

data flag was added to the network link

data to identify in which region each

roadway was located. This enhancement

allowed performance measures to be

extracted from only those portions of the

network located in the Cincinnati (OKI)

region.

Other minor modifications were required

to reformat the data for input into the IDAS

software. Additional modifications were

also required to perform a separate

analysis of the impacts of weather and

work zone mitigation strategies in the

Cincinnati region. These specific

modifications are discussed in a

subsequent section. 

Seattle

The Seattle regional models used in the

analysis represented travel demand in the

year 2003 for three separate time

periods: A.M. Peak Period, P.M. Peak

Period, and the Off-Peak Period. These

models were based on the Puget Sound

Regional Council (PSRC) travel demand

models. These models represented a

combined daily travel demand of

approximately 10.8 million person trips

23

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
traveling between 850 possible origins

and destinations. Five separate travel

modes were used in the analysis

including: Single Occupancy Vehicle,

High Occupancy Vehicle, Truck, Transit

(bus and rail), and Ferry. 

Several modifications were made to the

existing PSRC models to generate data

suitable to the analysis of full operations

and ITS deployment. The first modification

was the development of specific models

representing travel conditions in the year

2003. Travel demand data from existing

year 2000 and 2005 models were

interpolated to develop these interim year

models. 

A second modification to the Seattle

model networks was required to allow the

analysis of ramp metering strategies. Onramp facilities are not represented in the

current Seattle models. Instead, these

interchanges are coded similar to surface

street intersections and allow traffic to

move directly from arterial roadways to

freeway facilities. The IDAS software

typically requires that ramp facilities be

coded in the network to allow the analysis

of ramp metering strategies. When ramp

meters are deployed, additional

impedance is added to the ramp facilities

to simulate the impact of the ramp signal

on traffic entering the freeway. Since the

ramp facilities were not available in the

Seattle model network, modifications were

required to properly represent this impact.

Turning movement restrictions, available for

use in the IDAS software, were specially

modified to represent the additional

impedance caused by ramp metering

strategies in the absence of ramp facilities. 

A final modification to the Seattle models

was required to properly represent

automobile carrying ferries in the IDAS

analysis. Some reformatting of the model

data was necessary to properly account

for this specific travel mode that is

prevalent in the Puget Sound region. 

Additional Analysis for 

Estimating the Impacts of 

Weather and Work Zones

Analysis Scenarios

Additional analysis was conducted in

Cincinnati to identify the impacts, benefits,

and costs that could be expected with

the addition of specialized operations

and ITS strategies intended to counter

the effects of inclement weather and

help mitigate the negative impacts

occurring as a result of road construction

and maintenance. 

Additional scenarios were needed to

analyze these strategies because the

baseline networks obtained from the travel

demand model assume no inclement

weather or road construction activity. The

analysis scenarios that were developed

differed by four separate variables: the

presence of roadwork, weather conditions,

deployment intensity, and time of day.

These variables were defined as follows:

■ Presence of Roadwork –- Two separate

roadwork scenarios were evaluated,

including a network with a representative

sample of construction activity and a

network without road construction/

reconstruction activity. The impact of

roadwork activity was represented by

reducing facility capacities through the

construction zones, as described in a

subsequent section.

■ Weather Conditions –- Three separate

weather conditions were evaluated:

clear, rain, and ice/snow. The network

representing clear conditions was identical

to the baseline network obtained from

24

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
the travel demand model. The impacts

of the rain and ice/snow conditions

were represented by decreasing

capacities throughout the network, as

described in a subsequent section.

■ Deployment Intensity –- Several different

deployment intensities were evaluated.

These include a No Operations and ITS

Deployment Scenario, which did not

contain any ITS or operational

improvements, and a Full Operations

and ITS Deployment Scenario, which

contained the full compliment of

operations and ITS deployments. Note

that for those scenarios that contained the

negative impacts of inclement weather

or construction activity conditions, the

deployment scenario was enhanced

by adding either weather or work

zone mitigation strategies, or both, as

appropriate to the conditions included

in the scenario. These specific mitigation

strategies were not included in the

scenarios that did not contain either

the inclement weather or construction

activity. For example, the impacts of

work zone mitigation strategies were

only analyzed in those scenarios with

roadwork conditions. 

■ Time of Day –- Models representing

four separate time periods were

available for the Cincinnati region,

including A.M. Peak Period, P.M. Peak

Period, Mid-day Period, and Off-Peak. 

An analysis approach was developed

by creating a matrix of all the potential

combinations of these variables and then

discarding illogical combinations. For

example, no scenarios analyzing conditions

representing roadwork activity during ice/

snow conditions were evaluated since

little construction activity is anticipated in

the winter months. To accommodate these

variables in the analysis, 40 separate

scenarios were developed and analyzed.

Table A-1 presents these scenarios. 

The following sections describe how the

various impacts of weather and construction

activity were simulated on the network to

create these scenarios.

Simulation of Weather Impacts

Three different weather situations were

considered in this analysis—clear, rain,

and snow. Clear weather scenarios

were represented using the baseline

roadway network from the TDM. Scenarios

representing rain and snow weather

conditions were represented by reducing

the capacity of network roadways to

simulate the negative impact of the

inclement weather. Weather impacts

on capacity represented a weighted

average of suggested capacity reductions

from the Highway Capacity Manual 2000 A-3

and the FHWA’s Operations website

www.ops.fhwa.dot.gov. The capacity

reductions are shown in Table A-2.

Simulation of Construction 

Activity Impacts

The negative impacts of construction activity

were simulated on the model networks by

first identifying a set of construction projects

that would be representative of a typical

construction season. These were identified

by reviewing major regional construction

projects from the previous three years and

selecting a set of projects representative of

a typical construction season. Eight projects

were selected: four lane-addition projects,

two reconstruction projects, and two

25

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
26

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Weather Conditions Freeway Reduction Arterial Reduction

Clear None None

Rain -6% -6%

Ice/Snow -10% -12%

Table A-2. Capacity Reductions Used to Represent Inclement Weather Conditions

A-3 Transportation Research Board (2000). Highway Capacity Manual, Washington, D.C.

Weather Construction Activity? Scenarios with No 

Operation and ITS

Scenarios with Full 

Operation and ITS

Clear

No A.M. Peak

Mid-day

P.M. Peak

Off-Peak

A.M. Peak

Mid-day

P.M. Peak

Off-Peak

Yes A.M. Peak

Mid-day

P.M. Peak

Off-Peak

A.M. Peak

Mid-day

P.M. Peak

Off-Peak

Rain

No A.M. Peak

Mid-day

P.M. Peak

Off-Peak

A.M. Peak

Mid-day

P.M. Peak

Off-Peak

Yes A.M. Peak

Mid-day

P.M. Peak

Off-Peak

A.M. Peak

Mid-day

P.M. Peak

Off-Peak

Ice/Snow No A.M. Peak

Mid-day

P.M. Peak

Off-Peak

A.M. Peak

Mid-day

P.M. Peak

Off-Peak

Table A-1. Cincinnati Analysis Scenarios

resurfacing projects. The construction

schedules for these projects were also

evaluated to estimate the typical number of

days within a year in which construction

activity was estimated to occur. 

The construction projects were then coded

into those scenarios meant to analyze work

zone projects. Since the representative

construction activities represent real projects,

they were coded in the actual network

locations they occurred. The negative
impacts of the construction activities were

simulated by reducing the baseline

capacities for those roadway links identified

as being within the construction zone. This

reduction was conducted on an individual

link-by-link basis, based on the initial number

of roadway lanes, the number of lanes

closed during construction, and the type of

construction activity. The capacity reduction

for each individual link included in the work

zone was calculated by first subtracting out

the number of lanes anticipated to be closed

as a result of the construction activity. The

capacities of the remaining lanes were then

reduced based on the recommended

capacity reduction factor from the highway

capacity manual (based on the number of

lanes in normal conditions and the type of

construction activity). These capacity

adjustments, for the lanes remaining open

for the various projects, ranged from 75

percent of the original capacity for a twolane facility undergoing resurfacing to 93

percent of the original capacity for a 3+ lane

facility undergoing the addition of new lanes. 

Additional Weather and Work Zone

Mitigation Strategies

Additional weather and work zone

mitigation strategies were deployed and

analyzed in the appropriate Full Operations

and ITS Deployment Scenarios containing the

negative impacts of inclement weather and/

or construction activity. These operations

and ITS strategies are not currently included

as available components for analysis

within the IDAS tool. The software does

have the capability, however, to deploy

and analyze ”generic,” user-defined

components. For these generic deployments,

the user is provided the opportunity to

specify the impacts of the components.

The components are then analyzed

identically to all other existing deployments

in the scenario, providing the opportunity to

analyze the impacts of the user-defined

components side-by-side with existing IDAS

components to capture the full synergistic

impacts of all components. This capability

was used to simulate the weather and work

zone improvements on the network. 

The impacts used in the analysis to

represent weather and work zone

mitigation strategies were based on the

observed impacts from these types of

deployments, where available, or the

impact of similar operations and ITS

components already available within

IDAS. The impacts associated with the

various weather and work zone

mitigation strategies are presented in

Table A-3.

Estimating the Annual Impact 

of the Full ITS Deployment 

Scenario in Cincinnati

Each of the 40 individual scenarios were

analyzed separately to estimate the likely

traffic conditions that would occur for each

given time-of-day period with similar

weather, construction activity and

operations, and ITS deployment intensity.

The results of the individual scenarios

were then annualized by applying a

weight to each scenario representing

how many days a year that scenario

would be anticipated to occur in a

typical year.

The applied weights were developed by

reviewing historical weather patterns and

construction schedules. Historical weather

data from the National Weather Service

revealed that rain would be expected to

occur on 17 percent of days annually,

and measurable ice/snow precipitation

occurs on an average of 18 days per

year. A similar review of the construction

27

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
Strategy Analysis Impact

Weather

Weather ATIS/Road Weather 

Information Systems (RWIS)

• ATIS information reaches 40 percent of regional travelers. Of 

those travelers receiving the information, 25 percent were able 

to save 6.3 percent of their travel time. (Based on existing IDAS

ATIS methodology)

Work Zones

Work Zone ATIS • ATIS information reaches an additional 10 percent of travelers 

using the work zone corridors. Of those travelers receiving the

information, 25 percent were able to save 6.3 percent of their

travel time. (Based on existing IDAS ATIS methodology)

Work Zone Incident Detection • 15 percent reduction in incident duration in work zones. 15 

percent reduction in fuel use rate and emissions rates in work 

zone. (Based on existing IDAS methodology and information 

from similar work zone deployment in Albuquerque, NM)

Lane Merging Applications • 5 percent restoration of facility capacity in work zone. (Based 

on information from Midwest Smart Work Zone Initiative)

Alternative Route Management • 10 percent increase in facility capacity for selected parallel 

arterial corridors serving as diversion routes. (Based on existing 

IDAS methodology for traffic signal coordination)

Alternative Work Hours • Reduction in the number of days (annually) with construction activity

occuring in the peak hours, offset by lesser increase in the number

of days with construction occurring in the nighttime period. (Based

on information from Midwest Smart Work Zone Initiative)

schedules of the representative projects

included in the typical construction season

indicated that construction activity would

be expected to occur on 53 percent of

the days annually. The analysis further

assumed that 45 percent of the rain days

would occur during the construction season.

The number of days in a year was assumed

to be 250, representing the number of

weekdays in a year, not including

significant holidays. The historical rates

of occurrence for the various weather

and construction activities were then

applied to identify weights (in number

of days per year) for the No Operations

and ITS Deployment Scenarios. The

weights for the Full Operations and ITS

Deployment Scenarios were determined

similarly, with the following exception.

The weight representing number of days

with construction activity in the peak

periods was reduced to reflect the

impact of alternative work scheduling

strategies. The construction season for

the off-peak scenarios was then

extended to reflect the additional work

shifted to the nighttime periods. 

These identified weights were applied

to each scenario and the resulting

performance measures were summed for

the No Operations and ITS Deployment

and the Full Operations and ITS

28

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Table A-3. Impacts of Weather and Work Zone Mitigation Strategies
29

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

Table A-4. Annualization Weights for Cincinnati

Deployment Scenario. The summed

results were then compared to identify

the annual incremental benefits of the

Operations and ITS strategies. Table A-4

presents the annualization rates that

were applied in the analysis for each

possible scenario, and shows how the

proportion of days included in the

annualization changes between the No

Operations and ITS Deployment and Full

Operations and ITS Deployment

Scenarios. For the peak periods (AM,

Mid-day, and PM) the proportion of

days with road construction is reduced

between the No Operations and ITS

Deployment and Full Operations and ITS

Deployment Scenarios to represent the

impacts of alternative work hours. This

table also shows the impact of shifting

some of these roadwork activities to the

off-peak periods.

Study Caveats

As documented in this appendix, the

analysis of the three case study regions

were conducted using similar, but not

identical approaches and assumptions.

Therefore, comparisons of major trends

across the three regions are generally

valid. Caution should be applied in any

detailed cross-cutting analysis of specific

impacts, however, due to model and

approach differences that may have

skewed results. The differences in the

analysis approaches may make it difficult

to discern if variations observed between

the three regions are valid, or are a product

of the analysis methodology. Some of the

significant variations in the models and

approaches which have the potential to

impact results are documented below.

Tucson 

The analysis of impacts in the Tucson

region employed model data representing

average daily travel in the year 2025.

This region was the only one to use a

future forecast of travel demand. The use

of this future demand may result in the

inflation of benefits, relative to other

regions, since travel demand and related

congestion is presumably greater than in

the current year. The Tucson region was

Peak Periods

(Includes AM, Mid-Day, and PM Peak Periods)

Off-Peak Periods

No Ops and ITS Full Ops and ITS No Ops and ITS Full Ops and ITS

Scenario Days % Days % Days % Days %

Clear 49 20% 66 26% 49 20% 32 13%

Rain 21 8% 24 10% 21 8% 18 7%

Ice/Snow 46 18% 46 18% 46 18% 46 18%

Clear with

Roadwork

113 45% 96 38% 113 45% 130 52%

Rain with

Roadwork

21 8% 18 7% 21 8% 24 10%

TOTAL 250 100% 250 100% 250 100% 250 100%
also the only region where a single daily

forecast was used in the analysis. This

unique characteristic may have the impact

of decreased benefits relative to the other

areas because the daily traffic model does

not capture the impacts of increased

congestion during the peak hours. The

Tucson model was also not adjusted to

specifically analyze variations in weather

conditions or construction activity, as

was performed in Cincinnati. 

Cincinnati

The analysis of impacts in the Cincinnati

region used model data representing

travel conditions in 2003 for four separate

periods—A.M. Peak Period, Mid-day

Peak Period, P.M. Peak Period, and OffPeak Period—with the sum of these periods

equal to a single day. Further, additional

models were constructed from these base

models to represent traffic conditions during

different combinations of weather conditions

and road maintenance activity typifying a

normal construction season. These additional

models resulted in the analysis of ITS

impacts during 20 unique traffic conditions,

greatly adding sensitivity to the analysis

compared to the other regions. Because the

analysis produced increased benefit

estimates for those alternatives representing

inclement weather or construction activity,

it is likely that the overall benefits estimated

for Cincinnati are greater relative to the

other areas. The analysis in Tucson and

Seattle were not conducted with this sensitivity

to weather conditions or construction

activity, and would not have captured

these additional benefits.

Seattle

The Seattle regional models used in the

analysis represented travel demand in the

year 2003 for three separate time periods:

A.M. Peak Period, P.M. Peak Period,

and the Off-Peak Period. The results from

the Seattle analysis are, therefore, sensitive

to the variations in impacts caused by

peak period congestion. The Seattle

models were not adjusted, however, to

specifically analyze variations in weather

conditions or construction activity, as was

performed in Cincinnati.

In addition to the model differences noted

above, other factors and parameters

internal to the individual region’s models

may also affect the estimated impacts.

Model characteristics such as the length

of peak periods, volume-delay functions,

and mode choice sensitivity may also

promote differences in the analysis results.

30

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
Additional Caveats

Impacts of the operations and ITS

deployments on incident-related delay

were estimated in all three case study

regions. The use of incident-related delay,

non-recurring congestion, or travel time

reliability as a measure of system

performance is an emerging practice.

As yet, there is often little consensus on

the specific definitions of the performance

measures used or the analysis methodologies applied in different studies. In

this study, ”incident-related delay” is

estimated only for freeway facilities and

represents the expected amount of delay

occurring as a result of traffic incidents

(crashes, stalls, and breakdowns). This

performance measure is synonymous with

the ”travel time reliability” impact within the

IDAS analysis methodology. Current

incident data availability limits the application of this analysis methodology to only

freeway facilities and does not currently

allow for the estimation of incident-related

delay for other surface roadways.

Other caveats, specific to the individual

case study regions, are documented

within the individual reports.

31

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle
32

Benefits and Costs 

of Full Operations 

and ITS Deployment:

Seattle

U.S. Department of Transportation

400 7th Street, SW

Washington, DC 20590

FHWA-JPO-04-033 May 2005 EDL #13977

Intelligent 

Transportation 

Systems

ITS Web Resources

ITS Joint Program Office:

http://www.its.dot.gov

ITS Cooperative Deployment Network:

http://www.nawgits.com/icdn

ITS Electronic Document Library (EDL):

http://www.its.dot.gov/itsweb/welcome.htm

ITS Professional Capacity Building Program:

http://www.pcb.its.dot.gov