TRAFFIC 

CONGESTION

Road Pricing Can Help 

Reduce Congestion, 

but Equity Concerns 

May Grow

Report to the Subcommittee on 

Transportation, Housing, and Urban 

Development and Related Agencies, 

Committee on Appropriations, House of 

Representatives

January 2012

GAO-12-119

United States Government Accountability Office

GAO
United States Government Accountability Office

Highlights of GAO-12-119, a report to the 

Subcommittee on Transportation, Housing, 

and Urban Development and Related 

Agencies, Committee on Appropriations, 

House of Representatives 

January 2012 

TRAFFIC CONGESTION

Road Pricing Can Help Reduce Congestion, but 

Equity Concerns May Grow 

Why GAO Did This Study

Many Americans spend frustrating 

hours each year stuck in traffic. While 

estimates vary, the Department of 

Transportation (DOT) estimates that 

traffic congestion costs the United 

States $200 billion each year, and that 

more than one-quarter of total annual 

travel time in metropolitan areas 

occurs in congested conditions. Road 

pricing or congestion pricing—

assessing tolls that vary with the level 

of congestion or time of day—aims to 

motivate drivers to share rides, use 

transit, travel at less congested times, 

or pay to use tolled lanes. Since the 

first U.S. congestion pricing project 

opened in 1995, 19 project sponsors 

have 41 pricing projects in operation or 

under construction. About 400 miles of 

priced highway lanes including nearly 

150 miles on the New Jersey Turnpike

are in operation today with current tolls 

varying from 25 cents to $14.

All U.S. projects in operation are either 

High Occupancy Toll (HOT) lanes, 

which charge solo drivers to use newly 

constructed lanes or carpool lanes, or

peak-period pricing projects, which 

charge a lower toll on already tolled 

roads, bridges and tunnels during offpeak periods. GAO examined (1) the 

federal role in supporting congestion 

pricing, (2) results of U.S. congestion 

pricing projects, and (3) emerging 

issues in congestion pricing. Eight 

project sponsors have current and 

completed evaluations on at least 1 

project, for a total of 14 evaluated 

projects, all of which GAO reviewed. 

GAO interviewed officials about the 

performance of their pricing projects 

and effects. DOT provided technical 

comments, which GAO incorporated as 

appropriate.

What GAO Found

DOT approves all congestion pricing projects on roadways that receive federal 

funds and provides grants for project studies, implementation, and evaluation. 

Nearly all HOT lane projects and most peak-period pricing projects in operation 

today received federal funds at one time or another. DOT’s largest programs for 

congestion relief, the Urban Partnership Agreement and Congestion Reduction

Demonstration programs, have provided grant funds totaling nearly $800 million 

since 2006 to six metropolitan areas to implement pricing and other strategies.

DOT requires sponsors of congestion pricing projects to monitor and evaluate 

performance and, for HOT lanes when applicable, ensure that a federal standard 

for minimum traffic speeds is met. 

The 14 congestion pricing projects that have current and complete evaluations 

generally show that pricing can help reduce congestion, although other results 

are mixed, and not all possible relevant impacts have been assessed. HOT lane 

projects, which aim to reduce congestion by decreasing travel time and 

increasing speed and the number of vehicles using the lane, have reduced 

congestion, but some HOT lane projects also added new lanes, and studies did 

not distinguish the extent to which performance improvements were due to 

added lanes or pricing. In addition, although the number of cars using HOT lanes 

has risen, there were fewer people in those cars because of an increase in the 

proportion of toll-paying solo drivers or a decrease in carpools. Peak-period 

pricing projects, which aim to reduce congestion by encouraging drivers to travel 

at off-peak times, have shifted some travel to those times. Other congestion 

pricing effects—such as equity income impacts—have not always been 

evaluated. Potential concerns include income equity (whether low-income drivers 

are disproportionately affected by congestion pricing) and geographic equity 

(whether one geographic area is more negatively affected than another, such as 

when traffic diversion occurs). These impacts are important to assess as they 

address the public and elected officials’ concerns about the effects of pricing on 

travelers and communities. Ongoing multi-year evaluations across six 

metropolitan areas will assess the performance and effects of congestion pricing 

projects using a specific set of measures to assess the effectiveness of 

congestion reduction strategies. 

Concerns about equity may grow as pricing projects become more widespread. 

New projects are under construction, and several metropolitan areas have

networks of HOT lanes planned that will expand the relatively limited use of 

pricing today. Equity concerns may become more acute where sponsors are 

using pricing not only to manage congestion, but also to raise revenue to build 

new projects. Raising revenue can be at odds with managing congestion (e.g., 

increasing passenger throughput) if higher tolls can produce more revenue from 

fewer paying vehicles. Options to address equity issues include using a portion of 

toll revenues to finance public transit service.

View GAO-12-119 or key components.

For more information, contact Phil Herr at 

(202) 512-2834 or herrp@gao.gov. 
Page i GAO-12-119 Traffic Congestion 

Letter 1 

Background 2

DOT Helps Facilitate Congestion Pricing through Project 

Approvals and Funding for Implementation, Monitoring, and 

Evaluation 8

Project Evaluations Have Generally Shown Reduced Congestion, 

but Other Effects Have Not Been Consistently Assessed 15

Greater Equity and Safety Issues Might Develop as New Projects 

Are Implemented 25

Concluding Observations 31

Agency Comments 33

Appendix I Objectives, Scope, and Methodology 34

Appendix II Congestion Pricing Projects Open to Traffic in the United States, 2011 40

Appendix III DOT’s Value Pricing Pilot Program Grants, Fiscal Years 1999 

through 2010 42

Appendix IV Performance and Monitoring Requirements for Federal Programs for 

Congestion Pricing Projects 51

Appendix V GAO Contact and Staff Acknowledgments 55

Tables

Table 1: DOT Congestion Pricing Programs and Number of 

Operational or Under Construction Congestion Pricing 

Projects Authorized Under Each Program 9

Table 2: Five Common Performance Measures and Definitions 

Used in Current and Completed Congestion Pricing 

Project Evaluations 17

Table 3: Evaluations and Surveys Used to Analyze the Performance 

and Effects of Congestion Pricing Projects 37

Contents
Page ii GAO-12-119 Traffic Congestion 

Figures

Figure 1: U.S. Congestion Pricing Projects in Operation or Under 

Construction 5

Figure 2: Project Sponsors That Have Current and Completed 

Evaluations of Congestion Pricing Projects 16

Abbreviations 

CRD Congestion Reduction Demonstration

DOT Department of Transportation 

ELD Express Lanes Demonstration

FHWA Federal Highway Administration 

HOT High Occupancy Toll 

HOV High Occupancy Vehicle 

NEPA National Environmental Policy Act 

SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation 

Equity Act—A Legacy for Users 

SR State Route

UPA Urban Partnership Agreement

VPPP Value Pricing Pilot Program

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Page 1 GAO-12-119 Traffic Congestion 

United States Government Accountability Office

Washington, DC 20548 

January 12, 2012 

The Honorable Tom Latham 

Chairman 

The Honorable John Olver 

Ranking Member 

Subcommittee on Transportation, 

 Housing, and Urban Development 

 and Related Agencies 

Committee on Appropriations 

House of Representatives 

Many Americans spend frustrating hours each year stuck in congested 

traffic, a situation that costs the country billions of dollars annually and 

influences people’s decisions about where to live and work. As traffic has 

risen dramatically over the past 3 decades with population and economic 

growth, congestion now extends to more times of the day, more roads, 

and more cities and towns—thus affecting more people than ever before. 

Estimates of the cost of congestion vary; according to the Department of 

Transportation (DOT), congestion costs America an estimated $200 

billion each year in lost travel time and fuel, and drivers in metropolitan 

areas spent more than one-quarter of their total annual travel time in 

congested conditions. 

Metropolitan areas have undertaken several approaches to reduce 

congestion, but some approaches are becoming impractical and too 

costly. For example, metropolitan areas have widened or extended roads 

to add physical capacity, yet this option may not be feasible in some 

densely populated urban areas or could have significant social and 

environmental impacts. Furthermore, adding roadway capacity is costly at 

a time when governments at all levels are facing fiscal constraints. 

Metropolitan areas have also attempted to reduce congestion by 

managing existing infrastructure more efficiently, through traffic 

management strategies such as timed traffic signals, signs that warn 

drivers of congestion ahead, and improved responses to accidents. Other 

strategies, such as carpool or bus-only lanes, have been designed to 

reduce the number of vehicles on roadways by encouraging people not to 

drive alone. 

Another strategy to reduce congestion is road pricing or congestion 

pricing—assessing tolls that vary with the level of congestion and time of 

day. Since the first U.S. congestion pricing project opened in 1995, 19 

 
 

Page 2 GAO-12-119 Traffic Congestion 

project sponsors, generally state departments of transportation or local 

authorities, have 41 pricing projects either operational or under 

construction—primarily charging solo drivers to pay a toll on newly 

constructed lanes, existing carpool lanes, or charging a lower toll on tolled 

highways, bridges, and tunnels during off-peak periods. Concerns on the 

part of public and elected officials about the fairness of congestion pricing 

to all users have, however, been a challenge to instituting these projects. 

At your request, we examined (1) the federal role in supporting 

congestion pricing, (2) results of congestion pricing projects in the United 

States, and (3) emerging issues in congestion pricing projects. To 

address these objectives, we reviewed relevant legislation, literature, 

reports, and studies. We interviewed federal officials who oversee 

programs related to congestion pricing as well as experts in the field. We 

analyzed congestion pricing project performance from evaluations, 

related environmental and traffic diversion assessments, traveler surveys, 

and interviews with state and local transportation officials who have 

implemented and evaluated projects. See appendix I for our study 

objectives, scope, and methodology. 

We conducted this performance audit from October 2010 through January 

2012 in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives. 

Traffic congestion is caused by more vehicles on a road than it is 

designed to accommodate, and it can be exacerbated by several factors. 

For example, bottlenecks at highway interchanges or on bridges and 

tunnels can worsen congestion. Vehicles traveling at different speeds can 

increase the average amount of space between cars, thus not efficiently 

using all space available in a lane. Stop-and-go traffic leads to increased 

queuing and periodic events such as traffic accidents and roadway 

construction can compound already congested conditions. Although a 

transportation system is designed to handle a certain number of vehicles, 

the flow of traffic can be improved at certain times and places such as 

during rush hours or at bottlenecks. 

Background 
 

Page 3 GAO-12-119 Traffic Congestion 

Congestion pricing is designed to improve the flow of traffic by charging 

drivers a toll that can vary with the level of congestion or time of day. 

Drivers pay a higher price for using a lane or roadway at times of heavy 

traffic, and a lower price when and where traffic is light. To avoid toll 

payment, drivers may choose to share rides, use transit, travel at less 

congested (generally off-peak) times, or travel on less congested routes. 

Drivers who place a high value on time may choose to pay the toll to use 

the priced lane during congested times in return for a faster and more 

reliable trip. Alternatively, drivers who wish to pay a discounted toll on an 

already tolled roadway can travel at off-peak times. 

Economists generally believe that congestion pricing has the potential to 

alleviate congestion on roadways in an economically efficient way. Those 

who value a fast and reliable trip will pay for the option. Drivers who place 

a lower value on time will choose to stay in the unpriced and potentially 

more congested roadways. Economists believe that congestion pricing 

can also enhance economic efficiency by making drivers take into 

account the external costs they impose on others when making their 

travel choices. Any given driver’s highway use entails extra costs that the 

driver does not bear, in the form of congestion, noise, and pollution. Thus, 

paying a toll that reflects a driver’s value of time and covers external costs 

can potentially reduce congestion and the demand for road space at peak 

periods. We have reported that the existing infrastructure can be 

managed more efficiently and that congestion pricing could be one 

method to do so.1

All congestion pricing projects in the United States have used either (1) 

High Occupancy Toll (HOT) lanes or (2) peak-period pricing on already 

tolled facilities. HOT lanes have been created by constructing new lanes 

or converting existing carpool or High Occupancy Vehicle (HOV) lanes, 

some of which had been previously underused, and allowing solo drivers 

to use these lanes if they pay a toll. Users of the prior HOV-only lanes, 

such as carpools and express buses, generally continue to use the lanes 

for free and are allowed to use newly constructed HOT lanes for free as 

well. HOT lane operators seek to influence the number of vehicles in the 

HOT lane and maintain 45- to 55-mile-per-hour travel speeds through 

 

1

GAO, Reducing Congestion: Congestion Pricing Has Promise for Improving Use of 

Transportation Infrastructure, GAO-03-735T (Washington, D.C.: May 6, 2003); and 

Surface Transportation: Strategies Are Available for Making Existing Road Infrastructure 

Perform Better, GAO-07-920 (Washington, D.C.: July 26, 2007). 
 

Page 4 GAO-12-119 Traffic Congestion 

“dynamic” pricing—that is, increasing or decreasing tolls in real time 

depending on traffic in the HOT lane. Peak-period pricing on already 

tolled highways, bridges, and tunnels or on new or planned replacement 

facilities is another type of congestion pricing project in the United States. 

In this type of pricing, tolls are fixed higher during peak travel times and 

lower during off-peak times to encourage drivers to use the roadway offpeak. Three HOT lane projects have used a hybrid approach to dynamic 

and peak-period pricing called “variable” pricing. Variable pricing uses a 

pre-set schedule of tolls that is periodically revised to account for changes 

in congestion or other factors.

Since the first U.S. congestion pricing project was implemented in Orange 

County, California, in 1995, 19 project sponsors have initiated 41 pricing 

projects on highways, bridges, and tunnels. Projects operate in Georgia, 

Utah, Colorado, Maryland, and New Jersey with multiple projects in 

California, Florida, New York, Texas, Virginia, Minnesota, and 

Washington State. Of the 41 pricing projects, 30 are completed and open 

to traffic. The 30 opened projects include 12 HOT lane projects and 18 

peak-period priced facilities, covering about 400 miles of priced lanes. 

Projects range in length from 4.1 miles on the State Route (SR) 133 in 

Orange County, California, to nearly 150 miles on the New Jersey 

Turnpike,2

 

2

The New Jersey Turnpike discontinued off-peak discounts to out-of-state vehicles as of 

July 2011.

and charge tolls varying from 25 cents to $14. Eleven HOT 

lane projects are under construction; in addition, 2 of the 12 HOT lane 

projects in operation are extending the length of their tolled lanes. Figure 

1 shows congestion pricing projects in operation and under construction 

including extensions to existing projects. Appendix II provides additional 

details on congestion pricing projects and toll rates.
 

Page 5 GAO-12-119 Traffic Congestion 

Figure 1: U.S. Congestion Pricing Projects in Operation or Under Construction

More metropolitan areas across the country are using or plan to use 

pricing as a way to relieve congestion on highways and bridges, and 

some regions are planning to implement networks of HOT lanes. DallasFt. Worth, Atlanta, Minneapolis-St. Paul, Seattle, and the San Francisco 

Bay Area have networks of HOT lanes in their long-term plans. For 

example, the Metropolitan Transportation Commission of the San 

Francisco Bay Area proposes to add a 570-mile HOT lane network by 

2025 as part of its 35-year regional plan. The Washington State 

Department of Transportation proposes to convert carpool lanes to HOT 

lanes on nearly 300 miles in the Seattle/Puget Sound area. Such 
 

Page 6 GAO-12-119 Traffic Congestion 

networks are also being considered in Los Angeles, Washington, D.C., 

and the Miami-Ft. Lauderdale area.

Congestion pricing has raised equity concerns among the public and 

elected officials. In general, an analysis of equity issues examines how 

costs and benefits of projects are distributed among members of society. In 

the transportation economics literature, four concepts of equity are cited.

• The extent to which members of the same group are treated equally; 

for example, whether some people with the same income pay a larger 

amount in taxes or fees.

• The extent to which those who benefit from a project, such as a new 

lane, pay for those benefits; for example, is the lane paid for by a toll 

on users or by a state sales tax paid in part by persons who may not 

use or benefit from the lane?

• How the costs and benefits of a project are distributed across 

members of different groups such as high- and low-income people; for 

example, whether all groups pay in proportion to their income or 

whether low-income people pay proportionally more of their income 

for tolls than high-income people.

• The extent to which those who impose social costs bear those costs; 

for example, whether polluters or drivers on crowded highways pay 

the full social cost of their driving, or, if a toll causes diversion from the 

tolled highway to adjacent neighborhoods, those neighborhoods incur 

the costs of pollution and crowding.

While recognizing that all of these concepts of equity cited in the literature 

may be important, public and elected officials’ concerns regarding 

congestion pricing have been primarily with the latter two concepts of 

equity, in particular, what is termed income equity and geographic equity.

• Income equity refers to whether the costs of congestion pricing that 

users incur are proportional to their incomes, or whether low-income 

drivers are disproportionately affected. For example, low-income 

drivers may spend a greater proportion of their income to pay to travel 

at preferred times or incur greater costs in travel time by choosing 

alternate unpriced routes. High-income drivers, who, economists 

generally believe, place a higher value on their time, may be more 

likely to pay the toll and benefit from a faster trip than low-income 

drivers, thus possibly generating income equity concerns.
 

Page 7 GAO-12-119 Traffic Congestion 

• Geographic equity refers to how equally the costs and benefits 

associated with congestion pricing are distributed within an affected 

metropolitan area. For example, if one corridor in a metropolitan area 

has congestion pricing and another does not, drivers in the tolled 

corridor may incur greater costs than drivers in the untolled corridor 

because of the tolls they pay or the increase in travel time they incur 

by choosing an alternate route. Furthermore, drivers who choose to 

avoid the tolls and take an alternate route may contribute to 

congestion on the alternate route. Such diversion of traffic from tolled 

routes within a corridor can reduce the performance of the alternate 

untolled routes and negatively affect surrounding neighborhoods. 

Issues of equity are further complicated if this traffic is diverted 

through low-income and minority communities.

The transportation economics literature also suggests that the equity 

impacts of congestion pricing be assessed in comparison to 

alternatives—namely the predominant sources of funding roadways, such 

as motor fuel and sales taxes. Comparing these sources could address 

whether those who benefit from a project, such as a new lane, pay for 

those benefits; for example, is the lane paid for by users of the facility or 

by persons who may not use or benefit from the lane? According to the 

Transportation Research Board, it may be the case that tolling and pricing 

provide a more equitable means of funding roadways than these other 

alternatives.3 We have reported that tolling is consistent with the “user 

pay” principle because tolling a particular road and using the tolls 

collected to build and maintain that road more closely link the costs with 

the distribution of the benefits that users derive from it.4

 

3

The Transportation Research Board is part of the National Research Council and 

provides expert advice on transportation policy and programs through task forces, 

committees, and conferences among other activities. The board has reported that existing 

transportation funding mechanisms such as sales taxes are not inherently equitable 

because they can result in poorer households paying a larger share of their income than 

wealthier households, are required by nonusers and users of the system alike, and make 

no distinction between occasional or heavy users of the system. Thus, sales taxes are 

less equitable than fuel taxes and tolls, which are paid by users of the system based on 

their use. Transportation Research Board of the National Academies, “Equity of Evolving 

Transportation Finance Mechanisms,” Washington, D.C.: November 2011. 

4

GAO, Highway Finance: States’ Expanding Use of Tolling Illustrates Diverse Challenges 

and Strategies, GAO-06-554 (Washington, D.C.: June 28, 2006).
 

Page 8 GAO-12-119 Traffic Congestion 

As a general rule, charging tolls on highways constructed with federal 

funds is prohibited.5 However, Congress has enacted several exceptions 

that authorize DOT to permit tolling in certain instances.

DOT approves all congestion pricing projects on any roadway that 

receives federal funds. DOT approval grants the project sponsor 

permission to have congestion pricing on newly constructed roadways6

and lanes and converted HOV lanes through three programs. DOT also 

approves design exceptions and environmental reviews that allow for 

pricing on federally funded roads. DOT awarded funding to study, 

implement, and evaluate congestion pricing projects and DOT programs 

require monitoring and evaluation of pricing projects, although the level of 

detail varies by program. When applicable, DOT oversees projects and 

certifies that program performance standards have been met.

Congress has authorized DOT to approve tolling, which can include 

congestion pricing, through three programs.7 Table 1 provides a summary 

of the three DOT congestion pricing programs and number of operational 

or under construction congestion pricing projects authorized under each 

program.

 

5

23 U.S.C. § 301.

6

SR 520 in Seattle is tolling the existing bridge to fund a replacement bridge.

7

DOT also provides tolling authority through three other programs—the Section 129 

General Tolling program, the Interstate System Reconstruction and Rehabilitation Toll 

Pilot Program, and the Interstate System Construction Toll Pilot Program—that are 

focused on using toll revenues to pay for highway construction projects. While tolls may 

be set in such a way as to manage congestion under these programs, this is not a 

requirement.

DOT Helps Facilitate 

Congestion Pricing 

through Project 

Approvals and 

Funding for 

Implementation, 

Monitoring, and 

Evaluation

DOT Approves Tolling, 

Project Design Exceptions, 

and Environmental 

Reviews on Federally 

Funded Highways
 

Page 9 GAO-12-119 Traffic Congestion 

Table 1: DOT Congestion Pricing Programs and Number of Operational or Under 

Construction Congestion Pricing Projects Authorized Under Each Program

• Value Pricing Pilot Program (VPPP), authorized in the Transportation Equity Act for 

the 21st Century in 1998 (and preceded by the Congestion Pricing Pilot Program 

authorized in the Intermodal Surface Transportation Efficiency Act of 1991) is a pilot 

program for local transportation programs to determine the potential of different 

value pricing approaches to manage congestion, including projects that would use 

tolls on highway facilities. DOT can grant tolling authority to 15 state and local 

transportation agencies for this program. All but 1 of the HOT lane projects in 

operation and open to traffic and most peak-period pricing projects in the United 

States received VPPP funds at one time or another.

• Express Lanes Demonstration Program (ELD), authorized in Safe, Accountable, 

Flexible, Efficient Transportation Equity Act—A Legacy for Users (SAFETEA-LU) in 

2005, allows 15 demonstration projects to use tolling to manage high congestion 

levels, reduce emissions to meet specific Clean Air Act requirements, or finance 

additional Interstate lanes to reduce congestion. Five projects—4 of which are in 

Dallas-Ft. Worth, Texas, and the other in Ft. Lauderdale, Florida—have received 

tolling authority through this program, and 4 of these projects are under

construction.

• High Occupancy Vehicle (HOV) Facilities (HOT Lanes), authorized in SAFETEA-LU 

in 2005, permits states to charge tolls to vehicles that do not meet occupancy 

requirements to use an HOV lane even if the lane is on an Interstate facility. Eleven 

of the 12 operational HOT lane projects in the United States received tolling 

authority as part of the HOV Facilities program or VPPP and its predecessor—the 

Congestion Pricing Pilot Program. 

Source: FHWA. 

DOT has also approved design exceptions for certain highway projects that 

include congestion pricing. DOT has approved exceptions to highway 

standards to allow for changes to highways to increase capacity within the 

existing right of way or “footprint.” The Florida Department of 

Transportation received design exceptions for I-95 in Miami to convert parts 

of the median and shoulder lanes and to narrow other lanes from the 

standard 12 feet to 11 feet to make two HOT lanes in each direction. The 

Minnesota Department of Transportation has received design exceptions to 

convert shoulder lanes for electronic tolling and bus service during peak 

periods on I-35W in Minneapolis. This lane also serves as a HOT lane for 

solo drivers who pay a toll during the same period. The Minnesota 

Department of Transportation’s design exceptions included changes in lane 

width and shoulder width as well as advisory speed limits.
 

Page 10 GAO-12-119 Traffic Congestion 

In accordance with the National Environmental Policy Act of 1969, as 

amended (NEPA)8 and its implementing regulations as well as Executive 

Order 12898, DOT reviews projects to assess their anticipated 

environmental and socioeconomic impacts and to determine their need for 

any additional reviews. Projects that are deemed to have significant 

environmental impacts must prepare an Environmental Impact Statement.9

When it is unclear whether or not a significant environmental impact will 

occur as a result of the project’s impacts, an Environmental Assessment 

must be prepared. Environmental impacts may include effects on air, noise, 

water quality, wildlife, and wetlands. Additionally, projects may be required to 

undergo an environmental justice assessment to determine its impacts on 

low-income and minority populations.10 Projects that a federal agency has 

previously determined to have no significant environmental impacts may 

receive a categorical exclusion, meaning that they do not have to complete 

an Environmental Impact Statement or Environmental Assessment to comply 

with NEPA.11

 

8

Pub. L. No. 91-190, 83 Stat. 852 (Jan. 1, 1970).

DOT has approved categorical exclusions for congestion 

pricing projects that do not lead directly to construction and changes in the 

facility’s “footprint” in accordance with NEPA implementing regulations, along 

with projects that include new electronics and communications systems for 

tolling. According to project sponsors that we interviewed, pricing projects 

that have not changed a facility’s “footprint,” such as HOV to HOT lane 

conversions or peak-period pricing on already tolled highways, bridges, and 

tunnels, have received categorical exclusions. In addition, projects that have 

narrowed the width of lanes and converted medians and shoulder lanes that 

have not involved changing the “footprint” of the highway have received 

categorical exclusions.

9

23 C.F.R. § 771.115.

10Executive Order 12898 directs agencies to identify and address “disproportionately high 

and adverse human health or environmental effects of its programs, policies, and activities 

on minority populations and low-income populations...” Executive Order 12898, Federal 

Actions to Address Environmental Justice in Minority Populations and Low-Income 

Populations, 59 Fed. Reg. 7629 (Feb. 16, 1994).

11According to DOT regulations, a categorical exclusion can be granted where actions: 

“do not induce significant impacts to planned growth or land use for the area; do not 

require the relocation of significant numbers of people; do not have a significant impact on 

any natural, cultural, recreational, historic or other resource; do not involve significant air, 

noise, or water quality impacts; do not have significant impacts on travel patterns; or do 

not otherwise, either individually or cumulatively, have any significant environmental 

impacts.” 23 C.F.R. 771.117(a).
 

Page 11 GAO-12-119 Traffic Congestion 

DOT has provided funds to promote congestion pricing through several 

programs that involve tolling—the Urban Partnership Agreement (UPA) 

and Congestion Reduction Demonstration (CRD) programs and the Value 

Pricing Pilot Program (VPPP). UPA and CRD, the largest programs that 

involve tolling, advance congestion pricing through funding awards from 

10 separate grant programs.12

In addition, DOT has provided about $100 million in grants for studies, 

implementation, and some evaluations of congestion pricing projects 

through VPPP since it was established in fiscal year 1998. Nearly all 

congestion pricing projects in operation have received VPPP funds at one 

time or another for these purposes. About a third of total VPPP grants 

were awarded to fund three of the six UPA participants—Seattle in fiscal 

year 2007 and Minnesota and San Francisco in fiscal year 2008.

As part of one-time initiatives, the UPA and 

CRD participants—Seattle, Washington; San Francisco, California; 

Minneapolis-St. Paul, Minnesota; Miami-Ft. Lauderdale, Florida; Los 

Angeles, California; and Atlanta, Georgia—were provided approximately 

$800 million through grant programs to implement tolling as well as 

transit, technology, and telecommunications strategies to reduce 

congestion. Funds have been used to build new HOT lanes, convert HOV 

lanes to HOT lanes, establish electronic tolling systems, and purchase 

buses for express bus service on HOT lanes.

13

 

12The UPA and CRD programs gave priority consideration to participants applying for 

discretionary grants from DOT’s Federal Highway Administration’s Value Pricing Pilot 

Program; Interstate Maintenance Discretionary; Transportation, Community and System 

Preservation; Innovative Research and Bridge Deployment Program; Ferry Boat 

Discretionary; and Public Lands Highways programs. Funds are also used from the 

Federal Transit Administration’s Bus and Bus Facilities and Alternative Analysis programs; 

as well as Research and Innovative Technology Administration’s Intelligent Transportation 

Systems and Intelligent Transportation Systems Operational Testing to Mitigate 

Congestion programs. Funds go to project elements that must meet eligibility criteria for 

their respective grant program.

Before 

that, Congress authorized $11 million in fiscal year 2005 and $12 million 

per year for fiscal years 2006 through 2009 for projects that involve 

highway pricing, of which $3 million per year was set aside for nontolling 

projects, such as parking and car sharing projects. See appendix III for a 

list of VPPP grants and activities from fiscal years 1999 through 2010. 

13San Francisco’s SFPark uses congestion pricing by adjusting parking meter and garage 

prices up or down based on the demand for parking. Drivers can receive real-time 

information about where parking is available and at which price using personal mobile 

devices such as iPhones. This “demand-responsive” pricing encourages drivers to park in 

underused areas and garages, reducing demand for parking in overused areas. 

DOT Has Provided Funds 

for Studies, 

Implementation, and 

Evaluations of Congestion 

Pricing Projects
 

Page 12 GAO-12-119 Traffic Congestion 

VPPP funds have been used to:

• Study the potential of pricing in a corridor or region or the 

feasibility of a particular pricing project. Studies have 

examined the benefits of implementing variable pricing on an 

already tolled facility such as the Florida Turnpike in Miami-Dade 

County and the Pennsylvania Turnpike near Pittsburgh and 

Philadelphia. VPPP-funded studies have also examined the 

feasibility of extending HOT Lanes such as I-15 in San Diego, 

California.

• Implement elements of projects. Lee County, Florida, used a 

grant to purchase transponder readers for electronic tolling on two 

of its bridges. The Washington State Department of 

Transportation used VPPP funds to install electronic tolling 

technology on the SR 520 bridge that determine changes in tolls 

based on congestion.

• Evaluate specific projects. Evaluations studied the results and 

challenges of implementing pricing projects including SR 91 in 

Orange County, California; I-15 in San Diego; California; I-394 in 

Minneapolis, Minnesota; and I-10 and U.S. 290 in Houston, 

Texas. 

In addition to the funding provided through VPPP, federal funding is 

available for congestion pricing projects through other programs. For 

example, federal credit assistance available under the Transportation 

Infrastructure Finance and Innovation Act program has been used to help 

finance construction of HOT lanes for 7 projects including those on I-495 

in Virginia, I-635/I-35E in Texas, and I-595 in Florida.14

 

14The Transportation Infrastructure Finance and Innovation Act program provides federal 

credit assistance in the form of direct loans, loan guarantees, and standby lines of credit to 

finance eligible surface transportation projects of national and regional significance. 

In addition, states 

receive nearly $40 billion a year in federal funding for highways through a 

series of grant programs collectively known as the Federal-Aid Highway 

Program. These grant programs have also been used to help finance the 

construction of congestion pricing projects.
 

Page 13 GAO-12-119 Traffic Congestion 

The HOV Facilities program requires project sponsors to annually monitor 

and report HOT lane traffic speeds and is the only DOT tolling program 

that requires project sponsors to meet an annual performance standard.

In the case of an HOV facility with a speed limit greater than 50 miles per 

hour, vehicles must be able to travel at least 45 miles per hour 90 percent 

of the time during weekday morning and evening peak hours over a 180-

day period.15

For the Express Lanes Demonstration (ELD) program, project sponsors 

monitor and evaluate their projects’ performance and are required to 

report annually to DOT. DOT then reports to Congress on the 

performance of the ELD projects. Performance goals are in four 

categories—(1) travel, traffic, and air quality; (2) distribution of benefits

and burdens on users of the facility; (3) use of alternative transportation 

modes; and (4) use of revenue to meet transportation or impact mitigation 

needs.

If this standard is not met, the road operator must make 

changes to bring the facility back into compliance. Such changes could 

include raising tolls on paying cars or changing carpooling requirements 

to achieve the standard. DOT established this speed requirement 

because HOV lanes, by law, are transit “fixed guideway” facilities that 

encourage transit use and thus traffic must maintain speeds compatible 

with express bus service. Nearly all HOV to HOT lane conversions in 

operation have been authorized under either the HOV Facilities program

or VPPP (and its predecessor, the Congestion Pricing Pilot Program). 

Projects that were authorized under HOV Facilities have this performance 

requirement. DOT monitors the reported performance of HOT lanes 

authorized under the HOV Facilities program. According to DOT officials, 

there has not been a case in which a HOT lane has not met the standard.

16

 

15Pub. L. No. 109-59, § 1121(d) (Aug. 5, 2005). In the case of an HOV facility with a 

speed limit of less than 50 miles per hour, the minimum operating speed must not be more 

than 10 miles per hour below the speed limit.

Performance measures include changes in traffic volumes and 

traffic speed; average tolls charged for the year compared with the 

previous year; number of carpools and express bus ridership; and use of 

toll revenues, including the percentage of revenues used to mitigate 

impacts. Unlike HOV Facilities program projects, ELD program projects 

are not required by statute to meet specific performance standards. 

Because four of the five existing ELD projects are currently under 

16Pub. L. No. 109-59, § 1604(b)(7)(A).

DOT Requires 

Performance Monitoring 

for All Its Toll Programs 

and Compliance with 

Performance Standard 

for Its HOV Facilities 

Program
 

Page 14 GAO-12-119 Traffic Congestion 

construction and construction has not begun on the fifth, no performance 

reporting for completed ELD projects currently exists.

DOT also requires project sponsors that receive VPPP funds to monitor 

and evaluate the performance of their projects so that the agency can 

report results biannually to Congress as required by statute.17

Under the UPA and CRD programs, DOT has provided funds to the 

Battelle Memorial Institute to conduct an independent national evaluation 

of the effectiveness of the program’s four congestion reduction 

strategies—tolling, transit, technology, and telecommuting. Projects will 

be assessed individually and results compared across all projects in the 

six metropolitan areas according to specific metrics. These metrics 

include reductions in congestion delay and duration; increases in the 

number of cars and people in cars (i.e., vehicle and passenger 

throughput), and shifts to travel during off-peak times, among other 

factors.

Project 

sponsors report five categories of effects—(1) driver behavior, traffic 

volumes, and travel speeds; (2) transit ridership; (3) air quality; (4) equity 

for low-income individuals; and (5) availability of funds for transportation 

programs. As with the ELD program, projects that receive VPPP grants 

are not required to meet specific performance standards.

18

See appendix IV for list of performance and monitoring requirements for 

federal programs for congestion pricing projects. 

 

17Pub. L. No. 102-240, § 1012(b)(5), 105 Stat. 1914 (Dec. 18, 1991), as amended by Pub. 

L. No. 109-59, § 1604.

18Urban Partnership Agreement and Congestion Reduction Demonstration: National 

Evaluation Framework, U.S. Department of Transportation, Washington, D.C.: November 

21, 2008.
 

Page 15 GAO-12-119 Traffic Congestion 

Evaluations of 14 congestion pricing projects in the United States have 

generally shown reduced congestion, although other results are mixed, and 

not all possible relevant effects have been assessed. HOT lane projects, 

which aim to improve the flow of traffic and throughput with increased 

speeds and decreased travel times, have reduced congestion by 

increasing vehicle throughput, and have generally shown reduced 

congestion, increased speeds, and decreased travel times in the priced 

and unpriced lanes. Some HOT lane projects have added new lanes and 

thus, for these projects, the effects of pricing on performance have not 

been distinguished from the effects of the added lane. In addition, although 

the number of cars using HOT lanes has risen, there were fewer people in 

the cars—a fact attributed to an increase in the share of toll-paying solo 

drivers or a decrease in carpooling on HOT lanes. Peak-period pricing 

projects that aim to reduce congestion by encouraging drivers to travel at 

off-peak times have shifted some drivers to travel during those times. Other 

effects of congestion pricing projects, such as equity income impacts, have 

not always been evaluated. Evaluating these impacts is important to 

address public and elected officials’ concerns about the effects of pricing 

on travelers and communities. Not evaluating these effects leads to an 

incomplete understanding of the full effects of pricing.

Of the project sponsors that have operational congestion pricing, 8 have a 

current and completed evaluation of at least one of their projects, for a 

total of 14 evaluated projects. These eight evaluations assess five HOT 

lane projects and nine peak-period pricing projects, as shown in figure 2. 

For a description of our objectives, scope, and methodology in analyzing 

the congestion pricing projects, see appendix I.

Project Evaluations 

Have Generally 

Shown Reduced 

Congestion, but Other 

Effects Have Not 

Been Consistently 

Assessed
 

Page 16 GAO-12-119 Traffic Congestion 

Figure 2: Project Sponsors That Have Current and Completed Evaluations of Congestion Pricing Projects

Because of differences in project objectives and in DOT’s monitoring and 

evaluation requirements, the completed evaluations vary in which aspects 

of performance they report. No evaluation has assessed the performance 

of congestion pricing across projects. In addition, the evaluations 

represent an assessment of the results of the projects at specific points in 

time. Were the evaluations on-going or repeated at different time 

intervals, it is possible that the results would differ. The most common 

measures used across the evaluations have been travel time and speed, 

throughput, off-peak travel, transit ridership, and equity. Table 2 lists and 
 

Page 17 GAO-12-119 Traffic Congestion 

defines these five common performance measures and definitions used in 

congestion pricing project evaluations.

Table 2: Five Common Performance Measures and Definitions Used in Current and 

Completed Congestion Pricing Project Evaluations

Performance 

measure Definitions

Travel time and 

speed

How fast vehicles travel and how long it takes for the vehicles to drive 

from one end of the HOT lane to the other.

Throughput How many vehicles move through the HOT lanes and/or the corridor 

(vehicle throughput).

How many people move through the HOT lanes and/or the corridor 

(passenger throughput).

The average number of people in a vehicle (buses and cars) on the 

HOT lanes and/or in the corridor (average vehicle occupancy).

Off-peak travel Whether drivers change their behavior to travel during off-peak times.

Transit ridership Whether drivers change their behavior to take transit. 

Equity Income Equity: How the distribution of benefits from tolling are 

spread among commuters of all incomes in the corridor.

Geographic Equity: Whether drivers change their behavior to drive on 

alternative unpriced roadways within the same corridor as the priced 

roadway.

Source: GAO analysis of performance measures and definitions used in the assessed project evaluations.

Evaluations of HOT lane projects, which are designed to improve travel 

time and speed, have shown improvements. Both travel time and travel 

speed improved on at least some sections of all five HOT lane projects 

that were evaluated. Sometimes the improved travel times in the HOT 

lanes also led to improved travel times in the adjacent unpriced lanes 

because solo drivers paid to switch to the HOT lanes. For example, on 

SR 167 in Seattle, peak-hour travel speeds on the adjacent unpriced 

lanes increased as much as 19 percent compared with travel speeds in 

2007 while speeds on the HOT lanes remained about the same, 

Projects Improved 

Performance in Certain 

Areas According to Certain 

Measures, but Results for 

Other Measures Were 

Mixed and Varied by 

Project Type

Travel Time and Speed
 

Page 18 GAO-12-119 Traffic Congestion 

averaging the speed limit of 60 miles per hour.19

Evaluations of the nine peak-period pricing projects with completed 

evaluations reported no effects on travel time and speed. Two of these 

evaluations—of the New Jersey Turnpike and Lee County bridges—

analyzed these effects. Although travel times on the New Jersey Turnpike 

improved from 2000 to 2001 when electronic tolling and peak-period 

pricing were introduced at the same time, the project evaluation attributed 

the improvement mostly to electronic tolling and not to pricing.

According to the 

evaluation of I-15 in San Diego, drivers in the HOT lanes reportedly saved 

up to 20 minutes more than drivers in the adjacent unpriced lanes during 

the most congested times. Neither project included a new lane. Two other 

HOT lane projects—on I-95 in Miami and SR 91 in Orange County —

included two new lanes in each direction, which also helped improve 

travel times and speed. On I-95, for example, which Florida Department 

of Transportation officials identified as the most heavily congested 

highway in the state before pricing began in 2008, the evaluation reported 

that drivers have reportedly saved about 14 minutes in the HOT lanes 

and 11 minutes in the adjacent unpriced lanes per trip. Evaluations of the 

I-95 and SR 91 projects did not, however, isolate the effects of the added 

lane and pricing on performance. Isolating such effects is challenging 

because even if a study accounts for the increased vehicle throughput on 

the new lanes, it may then understate the throughput the other lanes 

could have handled if the new lanes had not been added.

Evaluations of all five HOT lane projects reported an increase in vehicle 

throughput—as measured by traffic volumes—on the HOT lanes and 

sometimes on the adjacent unpriced lanes and attributed this increase to 

both congestion pricing and the addition of new lanes. For example, 

according to a 2006 evaluation of the I-394 project in Minneapolis, vehicle 

throughput in the HOT lanes increased by 9 to 13 percent and by 5 

percent in the adjacent unpriced lanes after the lanes opened. A 2000

evaluation of the SR 91 project in Orange County estimated that vehicle 

throughput increased 21 percent on the entire roadway.

 

19The performance evaluation for SR 167 did not report the specific speeds for before and 

after implementation. It only reported the percentage increase between them. A graphic in 

the evaluation shows the increase from around 40 miles per hour in 2007 to about 50 

miles per hour in 2010 for the adjacent unpriced lanes while the HOT lanes stayed the 

same at 60 miles per hour. 

Traffic Throughput
 

Page 19 GAO-12-119 Traffic Congestion 

Four of the five HOT lane project evaluations that tracked the average 

number of people in a car (known as average vehicle occupancy) showed 

a decrease in the number of passengers per car. Thus, while there were 

more cars using the HOT lanes, there were, on average, fewer people in 

the cars, which project sponsors attributed to an increase of the share of 

toll-paying solo drivers or a decrease in carpooling in the HOT lanes. In 

addition, evaluations of two projects assessed passenger throughput 

which takes into account the number of people riding buses as well as the 

average vehicle occupancy rate to estimate the total number of people 

moved through the roadway. According to the evaluations, passenger 

throughput on I-15 in San Diego increased slightly between 1997 and 

1998, and then decreased between 1998 and 1999, and passenger 

throughput on I-95 in Miami increased 42 percent between 2008 and 

2010 on the HOT lanes—a result the evaluation attributed to an increase 

in toll-paying solo drivers, transit ridership, and the addition of two HOT 

lanes.

Evaluations of peak-period pricing projects found no increase in 

throughput due to congestion pricing. Specifically, evaluations of the New 

Jersey Turnpike and Lee County bridges assessed the impact of pricing 

on traffic volume and found no changes in vehicle throughput or average 

vehicle occupancy due to pricing that differed from overall traffic trends.

To evaluate two of the five HOT lane projects—I-15 in San Diego and SR 

91 in Orange County—project sponsors surveyed drivers to determine 

whether they changed their trips to travel at off-peak times. According to 

the I-15 survey results, some traffic shifted from the middle of the peak 

rush hour to the “peak-shoulder” times—the times directly before and 

after peak periods. However, the sponsors did not explain why this shift 

occurred. Drivers surveyed for the SR 91 evaluation said that the level of 

congestion affected their travel time decisions more than the presence of 

the toll. Project sponsors that did not study shifts to off-peak travel times 

said they did not do so because, in one case, the sponsor did not see the 

HOT lanes as offering incentives that would encourage peak-period 

travelers to shift their travel to off-peak periods, and, in another case, the 

sponsor was not required to study shifts to off-peak travel but would 

consider doing so in the future.

Sponsors of peak-period pricing projects conducted more robust studies 

of off-peak travel because it was a more explicit goal of their projects. 

These studies showed some success in reducing congestion during peak 

times. Evaluations for two of the three peak-period pricing projects 

showed that drivers chose to take trips at off-peak times on highways, 

Encouraging a Shift to 

Off-Peak Travel 
 

Page 20 GAO-12-119 Traffic Congestion 

bridges, and tunnels to take advantage of discounted tolls. For example, 

according to a 2005 performance evaluation of traffic on bridges and 

tunnels into New York City conducted by the City University of New York 

for the Port Authority of New York and New Jersey, car and truck traffic 

increased in off-peak periods for most crossings.20

An evaluation of peak-period pricing on the New Jersey Turnpike based 

on a driver survey found that work schedules or a desire to avoid traffic 

created a greater incentive for determining when to travel than a slightly 

lower toll for off-peak travel. Thus, it appears that drivers chose to travel 

at off-peak times because of congestion and not because of modest 

differences in price.

The evaluation 

reported more significant improvements in the morning before the peak 

periods than after the peak periods at the end of the day, which the 

evaluation attributed to drivers finding it easier to arrive at work early than 

to arrive at work later. According to this survey, a majority of drivers had 

little flexibility to change their schedule to travel at off-peak times. For 

example, truck drivers said that they could not adjust their delivery 

schedules to travel at off-peak times. Furthermore, drivers said that the 

toll difference of $1 was not great enough to influence them to change 

their travel time. Despite this, a significant minority could alter their travel 

departure times between 30 minutes and 2 hours. Thirty-five of the 505 

surveyed drivers representing 7.4 percent of passenger trips said that 

they changed their travel behavior as a result of the project. According to 

the Port Authority, the 7.4 percent change in passenger trips to off-peak 

times is significant, since small changes can have exponential effects 

because of traffic queuing.

Evaluations of four of the five HOT lane projects assessed changes in 

transit ridership, but results were mixed. I-95 in Miami was the only one 

with demonstrated increases in transit ridership. Between 2008 and 2010, 

the average weekday ridership on the I-95 express bus increased by 57 

percent, from about 1,800 riders in 2008 to more than 2,800 in 2010. 

About 38 percent of these riders reported in a transit rider survey that 

 

20While the performance evaluation for the Port Authority crossings did not report the 

specific increases and decreases in traffic, it reported and measured the statistical 

significance of these changes. The evaluation stated that results indicated statistically 

significant increases in the percent share of off-peak period car and truck traffic for most 

crossings. Morning pre-peak increases were significant on more crossings than post-peak 

increases. Peak-period truck traffic decreased significantly on all crossings. Car traffic also 

decreased for peak-period crossings, but these results were not statistically significant.

Changes in Transit Ridership
 

Page 21 GAO-12-119 Traffic Congestion 

they used to drive alone. The other three HOT lane project evaluations 

found no increase in transit ridership on buses using the HOT lanes as a 

result of the project. While transit ridership reportedly increased on I-15 in 

San Diego, the evaluation stated that this increase was not linked to the 

project. Evaluations of all three peak-period pricing projects assessed 

whether drivers shifted to transit, but none found evidence of any 

changes in transit ridership.21

Many efforts have been made to assess the effects of congestion pricing 

projects on equity, including income equity (the distribution of costs and 

benefits of congestion pricing between low- and high-income drivers) and 

geographic equity (the relative effects of congestion pricing on two 

geographic areas, including the effects of any traffic diversion). Three of 

the eight evaluations, covering one HOT lane project and three peakperiod projects, attempted to assess both income and geographic equity, 

and none attempted to assess other effects on equity, such as whether 

members of the same group are treated differently or to what extent the 

beneficiaries of a project, such as a new lane, pay for those benefits.

Income Equity 

Evaluations for four of the five HOT lane projects attempted to assess 

equity through surveys or focus groups of travelers concerning their use 

of congestion pricing projects; however, different elements of equity were 

evaluated. For example, three of the four HOT lane project evaluations 

that assessed equity did so by considering the effects of congestion 

pricing on drivers of different income levels. Results for these three 

projects—SR 91 in Orange County, I-394 in Minneapolis, and SR 167 in 

Seattle—indicated that drivers of all incomes used the HOT lanes, but 

high-income drivers used them more often than low-income drivers.22

 

21Many factors determine whether a driver will shift to transit including availability and 

accessibility of transit options. While transit was available in the locations studied, we did 

not independently determine the robustness of that service during the time that the 

evaluation was conducted. 

In 

addition, evaluations for all four HOT lane projects—SR 91 in Orange 

County, I-394 in Minneapolis, SR 167 in Seattle, and I-15 in San Diego—

found that drivers liked having the option of using the HOT lanes and thus 

were supportive of them. The fifth HOT lane project—I-95 in Miami—has 

not undergone an assessment of the effect of congestion pricing on low22The definitions of low- and high-income populations varied by study. 

Equity
 

Page 22 GAO-12-119 Traffic Congestion 

income drivers because, according to the project sponsor, the benefits of 

congestion pricing—including increased travel speeds—accrue to all 

users.

Evaluations of the nine peak-period pricing projects considered different 

elements of equity and found few impacts. However, all three projects 

were previously tolled and toll discounts were offered for travel at off-peak 

times. Thus, no tolls, including those for peak periods, were raised. The 

New Jersey Turnpike Authority evaluated the income and ethnicity of 

those who shifted to the off-peak times, while the Lee County Department 

of Transportation assessed the age, gender, and work schedules of those 

who shifted to the off-peak times. Both project sponsors also surveyed 

drivers, who said they thought the off-peak discounts were equitable and 

the pricing program fair. However, the sample sizes for both these 

surveys were small; thus, the results may not provide reliable estimates 

for the various subgroups they measured.

Geographic Equity

Evaluating geographic equity—or the effects of any traffic diverted from 

HOT lanes or from peak-period priced highways, bridges and tunnels 

onto unpriced lanes and roads—would provide decision makers with 

information about potential negative effects, such as whether traffic on the 

unpriced alternatives increased. The sponsor of one of the five HOT lanes 

projects—SR 91 in Orange County—studied diversion and reported that 

traffic was drawn to the roadway and its HOT lanes because the priced 

lanes were new and added capacity. Sponsors of the other four HOT lane 

projects did not evaluate traffic diversion for several reasons, according to 

the sponsors. First, drivers can choose to drive in the unpriced lanes and 

none of the projects took away an unpriced lane—only HOV lanes were 

converted. Furthermore, two of the HOT lane projects added a lane to the 

roadway and allowed solo drivers to use a previously underused HOV 

lane. As a result, the sponsors said they expected drivers to be diverted 

to the HOT lanes, not away from them. Second, even if they had 

anticipated traffic diversion to alternative roads, the sponsors said they 

would not have surveyed drivers or asked them to maintain travel diaries 

because these methods were expensive and challenging to implement. 

They added that electronic data collection methods, such as GPS 

tracking in vehicles, transponder tracking, and license plate tracking, can 

be expensive and raise privacy issues.

Two peak-period pricing project sponsors—the New Jersey Turnpike 

Authority and the Lee County Department of Transportation—studied 
 

Page 23 GAO-12-119 Traffic Congestion 

traffic diversion to adjacent unpriced roads and found no evidence of 

diversion. According to the studies, such diversion would not be likely for 

these roadways because there are no comparable alternative routes.23

Other Equity and Environmental Concerns

Furthermore, the projects were previously tolled and congestion pricing 

was implemented with off-peak discounts. As for the HOT lane projects, 

traffic diversion may be less of a concern if a highway, bridge, or tunnel 

was previously priced than if it was previously unpriced.

Sponsors of one HOT lane project—SR 167 in Seattle—and one peakperiod pricing project—the New Jersey Turnpike—evaluated the impact of 

pricing on minorities. An environmental justice assessment for SR 167 

found that there would not be a disproportionate effect on minorities 

because there was a small minority population in the area, the project 

was limited to 9 miles southbound and 11 miles northbound, and there 

were unpriced alternatives—adjacent lanes and roads—that could be 

used.24

Evaluations of three HOT lane projects—I-15 in San Diego, SR 91 in 

Orange County, and I-394 in Minneapolis—and one peak-period pricing 

project—the New Jersey Turnpike—assessed environmental effects. All 

four evaluations assessed the impacts of pricing on air quality, and one 

HOT lane project—I-394—also assessed noise impacts. The air quality 

assessments, designed to test whether air quality improved as experts said 

it could with fewer cars idling in traffic, showed mixed results: minimal air 

quality improvements were reported on I-15, I-394, and the New Jersey 

Turnpike, but no effects on SR 91. The noise impact assessment on I-394 

found that there would be no significant noise impacts resulting from 

pricing.

The 2005 New Jersey Turnpike evaluation found that there would 

be no disproportionate effect on minority populations; however, as 

mentioned before, the survey sample size was small and therefore its 

results cannot be generalized to all users.

 

23The New Jersey Turnpike parallels I-295 in the southern part of the state and other 

roadways parallel the turnpike in the northern part of the state, but no roadway runs the 

entire length of the state to form a parallel alternative route. 

24SR 167 HOT Lanes: Social, Economic and Environmental Justice Report, Washington 

State Department of Transportation, January 2007. 
 

Page 24 GAO-12-119 Traffic Congestion 

The completed performance evaluations provide some information as to 

the effectiveness of congestion pricing, but the UPA and CRD evaluation 

framework has the potential to provide decision makers with a more 

consistent and comprehensive picture of the effects of pricing. The UPA 

and CRD evaluations which began in 2009 will collect data on UPA and 

CRD projects in the six metropolitan areas for 1 year before a project is 

implemented and then for another year after it has been implemented to 

assess its effects. The evaluation framework will provide standard 

performance measures such as travel times and vehicle throughput and 

help develop a more comprehensive study of congestion pricing, 

including increased monitoring of passenger throughput and socioeconomic information of HOT lane users. Performance measures and 

detailed metrics will be used to assess individual projects and across 

projects, which has not been consistently done so far. The evaluation 

framework will also assess the impacts of pricing on low-income drivers 

and changes in their travel time and distance traveled as a result of 

pricing. Travel diary surveys will be conducted at two of the UPA sites, 

which may provide some basis to study equity impacts including whether 

driver behavior changes based on income, such as diverting traffic to 

adjacent unpriced roads. In addition, the evaluation framework will include 

surveys to assess transit ridership for all projects that have a transit 

element. Despite the potential for greater understanding of the effects of 

congestion pricing as part of the UPA and CRD evaluation framework, 

evaluations have only been completed in one of the six metropolitan 

areas—and this was for its first phase.25 Thus we cannot assess the 

evaluation framework or surveys’ effectiveness until they are completed. 

DOT expects to have all of the UPA project evaluations completed by 

2014.

 

25The Florida Department of Transportation completed an evaluation of the first phase of 

its HOT lanes project. The UPA National evaluation team—consisting of the Battelle 

Memorial Institute, the Texas Transportation Institute, and the Volpe National 

Transportation Systems Center—coordinated with the Florida Department of 

Transportation’s evaluation. The national evaluation team will conduct the evaluations for 

the other five localities. The Volpe National Transportation Systems Center is conducting 

the travel diaries study. 

UPA Evaluations Should 

Improve Understanding of 

the Performance and 

Impacts of Congestion 

Pricing
 

Page 25 GAO-12-119 Traffic Congestion 

Income and geographic equity concerns may become more prevalent as 

congestion pricing becomes more widespread. Such concerns could be 

particularly relevant for HOT lane projects with a potential for large toll 

increases, such as projects that must meet HOV Facilities program 

performance requirements to maintain traffic speeds of 45 to 55 miles per 

hour. Tolls on pricing projects in operation are relatively low, but can be as 

high as a dollar per mile. Though currently capped, these tolls could be 

raised if necessary to maintain the required traffic speeds. In turn, higher 

toll rates could lead to more traffic diversion if drivers chose not to pay for 

HOT lanes and took adjacent unpriced lanes or roads instead.

These concerns may be particularly acute in the future for projects 

designed to use pricing not only to manage congestion but also to meet 

toll revenue targets. SR 520 in Seattle, which began pricing in December 

2011, will generate toll revenues to pay for bonds to build a replacement 

bridge. All cars, including carpools, pay a toll that varies up to $5.00. 

Registered vanpools, express buses, and emergency vehicles have free 

use. Because this is the first project to toll a previously untolled bridge 

and there are parallel alternative routes, traffic diversion may become a 

concern. According to traffic models from the area’s transportation 

planning council, traffic could increase on the parallel Interstate route by 5 

to 8 percent and on an alternative state road by 5 percent. Geographic 

equity concerns could be minimized by introducing tolling on both the 

Interstate and state road because drivers on all three routes would then

pay a toll and diversion from tolled routes to untolled routes would be less 

of a concern. However, according to officials in the Seattle metropolitan 

area, the public and elected officials are opposed to tolling these other 

routes.

Several other projects under construction involve public-private 

partnerships that plan to use toll revenues to pay for construction debt, 

operations, maintenance, and provide a return to private investors. 

However, meeting revenue targets can be at odds with policies to 

Greater Equity and 

Safety Issues Might 

Develop as New 

Projects Are 

Implemented

Expanded Use of Pricing 

Could Raise Equity 

Concerns
 

Page 26 GAO-12-119 Traffic Congestion 

increase throughput on highways and bridges by encouraging more 

people to use carpools and express bus service. According to one expert, 

project sponsors seeking to maximize revenue could in theory charge a 

higher toll and make more money off of fewer paying vehicles. Raising 

revenue could be at odds with managing congestion (e.g., increasing 

passenger throughput) if higher tolls can produce more revenue from 

fewer paying vehicles. In addition, as we have previously reported, tolls 

on roadways operated by private concessionaires can be expected to be 

higher than on comparable facilities operated by public agencies.26

Greater equity concerns could also be raised as decision makers

consider introducing tolling and pricing into previously untolled facilities. 

For example, the Port Authority of New York and New Jersey is 

conducting a study to assess the potential for improving throughput by 

converting an unpriced lane to a HOT lane on the approach to the Lincoln 

Tunnel during peak periods. Under the proposal, buses and carpools with 

three or more passengers would continue to have free access, but solo 

drivers would pay a toll. According to project sponsors, such switching 

would be positive because it would increase the number of people going 

through the tunnel at peak times.

Three 

projects—I-495 in Northern Virginia and the LBJ Express (I-635/I-35E) 

and North Tarrant Express (I-820-SH 121/183) in Dallas-Ft. Worth—are 

public-private partnerships in which the private operator sets the toll rate. 

I-595 project in Broward County, Florida, is also a public-private 

partnership, but the state department of transportation has retained the 

authority to set the toll rate.

27

 

26GAO, Highway Public-Private Partnerships: More Rigorous Up-front Analysis Could 

Better Secure Potential Benefits and Protect the Public Interest,

However, converting an unpriced lane 

to a priced one does not have much public or political support. According 

to DOT officials, no pricing project to date has involved the conversion of 

an unpriced lane to a HOT lane—all projects thus far have involved the 

GAO-08-44 (Washington, 

D.C.: Feb. 8, 2008).

27In addition, I-95 in Miami has raised its carpool occupancy requirements for free use 

from two to three passengers. Thus, two-passenger carpools pay a toll to use the HOT 

lanes or use the adjacent unpriced lanes. According to the Florida Department of 

Transportation, it has not studied the impact of pricing on two-passenger carpools and 

therefore does not know how many people have been affected.
 

Page 27 GAO-12-119 Traffic Congestion 

conversion of HOV lanes or the addition of new lanes.28

While future pricing projects may raise equity concerns, these concerns 

should be weighed against the potential benefits, including enhancing 

economic efficiency, increasing throughput, and reducing congestion. For 

example, greater use of pricing could enhance economic efficiency by 

discouraging solo driving and making alternatives such as carpooling or 

taking transit more appealing, thus resulting in more efficient use of existing 

roadways. Such changes in drivers’ behavior could also improve 

throughput and reduce congestion. In addition, as previously discussed, 

the equity impacts of congestion pricing can also be assessed in 

comparison to the equity concerns raised by the alternatives—namely the 

prevalent sources of funding roadways such as motor fuel and sales taxes.

The SR 520 

bridge in Seattle is the only previously unpriced facility to be fully priced. 

According to experts, pricing existing unpriced lanes and roadways could 

lead to geographic equity concerns as drivers divert to alternate routes to 

avoid tolls.

A number of options are also available to address equity issues. One 

such option is to use a portion of toll revenues for alternative 

transportation modes in the highway corridor, such as express bus 

service on HOT lanes. In general, bus riders are disproportionately lowerincome individuals who would benefit from both reduced congestion on 

the HOT lanes and increased transit investments from toll revenues. In a 

survey of Seattle residents, public support for tolling the SR 520 bridge 

grew substantially if a portion of the toll revenue was dedicated to transit, 

even if tolls had to be significantly higher to pay for transit service. As part 

of its UPA program funding, Seattle has received grant funds for new 

buses to begin service on the SR 520 bridge. Other UPA program 

participants, including Minnesota and Miami, have received DOT grants 

for express bus service on HOT lanes. Under the ELD program, Federal 

law permits the use of excess toll revenue for eligible highway and/or 

 

28A proposal to charge a toll for vehicles entering lower Manhattan though supported by 

the city’s mayor and approved by the City Council, was not adopted by the state 

legislature. This would have been the first project that charged a toll to access an area 

that was free before, known as cordon pricing. 
 

Page 28 GAO-12-119 Traffic Congestion 

transit service;29 however, pricing projects generally have not had excess 

revenues.30

I-25 in Denver has taken steps to address equity among passengers and 

drivers on the HOT lanes by setting its peak period toll rate based on the 

fare charged to express bus passengers on the HOT lanes. Thus, as the 

fare for express bus passengers increases, the toll rate for drivers to use 

the HOT lanes also increases.

Officials with the transportation planning council for the 

Minneapolis-St. Paul area told us that revenues from the I-394 project 

have generally not exceeded the project’s operational costs and therefore 

local transit funds are being used, as they were before the project was 

initiated, to provide express bus service on the HOT lanes. The San 

Diego Association of Governments also has used bus fare revenue to 

fund express bus service on I-15 in San Diego because the HOT lanes 

have not generated enough toll revenues to pay for bus service. In 

addition to the availability of revenues, the effectiveness of providing 

revenues to transit to address equity also depends on the availability of 

transit service and traveler commuting patterns. Transit may not be an 

option for some travelers given the location of homes, jobs, and other 

travel destinations.

An additional option to address equity issues would be to use toll 

revenues to reimburse low-income drivers, whether by exempting them 

from paying tolls or by providing them with a tax credit for the difference 

between the toll and transit fares. However, such reimbursement 

programs would involve complex efforts to determine and verify drivers’ 

low-income status. Nonetheless, some states such as California offer 

discounted utility rates for eligible households and in these states, 

transportation agencies have considered whether to use these preexisting 

mechanisms for eligibility and enforcement to provide discounted toll 

rates. However, no pricing project has used this option. Some experts 

have noted that discounts on tolls for low-income drivers would 

counteract the goal of reducing congestion because the discounts would 

 

29Pub. L. No. 109-59, § 1604, at 23 U.S.C. § 129. Depending on the program, the ability 

to use toll revenue for transit and other such purposes may be limited. The ELD program 

permits use of excess toll revenue for eligible highway or transit projects after revenues 

have been used for repayment of debt, reasonable return on investment of any private 

financing, and maintenance of facility.

30According to DOT, I-95 in Miami, SR 91 in Orange County, and I-25 in Denver have 

generated excess revenues. 
 

Page 29 GAO-12-119 Traffic Congestion 

encourage continued driving. Instead, they propose charging the same 

tolls to all users, but returning revenues to affected groups, such as 

groups of vehicle owners or a class of residents. VPPP federal funds 

were used to study the potential of providing credits for low-income 

highway users in Alameda County, California but no pricing project has 

used this option.

To provide insight on environmental justice issues, DOT approved two 

VPPP grants for fiscal year 2010-2011 to assess the impacts of pricing on 

low-income drivers. One grant, for I-30 in Dallas-Ft. Worth is to examine 

environmental justice issues related to pricing I-30 through the use of 

Intelligent Transportation Systems technology. According to DOT, “the 

project is important because it will provide more data on environmental 

justice and pricing, given that there is little experience with strategies 

designed to address these issues related to the introduction of pricing.” 

The other grant, for a pricing project in Hartford, Connecticut, is to study 

the application of pricing and the impacts of environmental justice issues 

that resulted from the original construction of a project.

Many highway projects increase the capacity of a roadway by converting 

shoulders or narrowing lanes which has the advantage of eliminating the 

need to widen highway and acquire additional property—of particular 

advantage in urban areas. Several congestion pricing projects have 

employed this strategy. For example, the Minnesota Department of 

Transportation has converted bus-only shoulder lanes on I-35W in 

Minneapolis to serve as HOT lanes during peak periods and has 

narrowed traffic lanes from 12 feet to 11 feet. In addition, as previously 

noted, the Florida Department of Transportation has incorporated portions 

of its medians and shoulders and narrowed traffic lanes from 12 feet to 11 

feet to create two HOT lanes on I-95 in Miami. Moreover, two new 

projects—Loop 131

 

31Also known as Mopac (Missouri Pacific) Expressway; it is one of two major existing 

north-south controlled-access highways in the Austin area.

in Austin and I-94 in Minneapolis—will create new 

capacity by using shoulders and narrowing traffic lanes. The Loop 1 

project will reduce shoulder width and incorporate parts of the shoulders 

to create an express lane, while the I-94 project may, if implemented, use 

shoulders and narrowed traffic lanes to create a HOT lane between 

Potential Safety Issues 

May Occur with Pricing 

Converted Shoulder Lanes 

and Narrowing Lanes
 

Page 30 GAO-12-119 Traffic Congestion 

Minneapolis and St. Paul. According to the project sponsor, I-94 does not 

have the space to build new HOT lanes if shoulders are not incorporated. 

Projects that convert shoulders and narrow lanes to create new lanes, 

including congestion pricing projects, raise concerns about driver safety 

and highway operations that transportation planners must address. 

Additional lanes on converted shoulders remove the safety refuge areas 

for motorists during vehicle breakdowns and emergencies and must be 

approved by DOT. According to the American Association of State 

Highway Transportation Officials, highways with paved shoulders have 

lower accident rates. Paved shoulders provide space to make evasive 

maneuvers; accommodate driver error; and add a recovery area to regain 

control of a vehicle, among other things. In addition, an analysis by the 

Highway Safety Information System32 sponsored by DOT reported that 

narrowing lanes or using shoulders to expand urban highways increased 

accidents by 10 percent. With traffic moving faster in the additional (or 

HOT) lane and slower in the unpriced lanes, the potential for sideswiping 

and lane-changing accidents increases. Another study conducted by the 

Texas Transportation Institute found that maintaining a shoulder and a 

wider HOV lane than adjacent unpriced lanes can help mitigate safety 

concerns.33

FHWA officials in Florida suggested that some of these safety issues 

could be mitigated using an incident management system, such as the 

one the Florida Department of Transportation has used on I-95 since 

2008. As a condition of approving several design exceptions, FHWA 

required the Florida Department of Transportation to implement Intelligent 

Transportation Systems to mitigate safety issues related to incorporating 

a shoulder and narrowing lanes on I-95 in Miami. While using an incident 

management system does not prevent incidents from occurring, cameras 

can survey highways and detect incidents such as accidents, debris, and 

stalled vehicles. Highway message signs then convey information to 

drivers about the incidents and traffic conditions. Florida Department of 

 

32The Highway Safety Information System is a multi-state database that contains crash, 

roadway inventory, and traffic volume data for a select group of states and is managed by 

the University of North Carolina Highway Safety Research Center under contract with the 

Federal Highway Administration. 

33Texas Transportation Institute, Guidance for Future Design of Freeways with HighOccupancy Vehicles (HOV) Lanes Based on an Analysis of Crash Data from Dallas, 

Texas (College Station, Texas: September 2003). 
 

Page 31 GAO-12-119 Traffic Congestion 

Transportation staff can summon emergency, police, and tow truck crews 

to resolve problems and direct traffic. Thus, in the event of an incident on 

the HOT lanes, the lanes can be closed and, because there are no 

permanent barriers between the HOT lanes and the adjacent unpriced 

lanes, traffic can be diverted to the adjacent unpriced lanes. In the event 

of an accident in the unpriced lanes, the lanes can be closed and traffic 

diverted to the HOT lanes and tolls temporarily lifted.

Since the HOT lanes on I-95 opened for traffic in December 2008, 

preliminary safety data found that the number of reported incidents 

involving accidents, debris, and stalled vehicles in the northbound 

express lanes increased from 132 in fiscal year 2009 to 209 in fiscal year 

2010.34 Florida Department of Transportation officials have suggested, 

however, that the actual number of incidents may not have increased but 

that incidents are now tracked more accurately. In addition, according to 

FHWA officials in Florida, the number and severity of crashes declined 

after the I-95 HOT lanes became operational. In their view, the HOT lanes 

decreased congestion, and as a result, fewer rear-end crashes occurred. 

Additionally, FHWA officials stated that they have not seen evidence of 

more sideswiping since the traffic lanes were narrowed to form the HOT 

lanes. The UPA and CRD National Evaluation will assess the safety 

impacts of pricing, including the number of accidents and their severity 

and any change in the perception of safety by travelers and emergency 

personnel since pricing began.

Although traffic congestion has declined recently in many metropolitan 

areas, future demand for travel during peak times is expected to increase 

as the population grows and the economy recovers. Fiscal and 

environmental concerns prevent building new capacity in many 

metropolitan areas. Transportation decision makers have a variety of traffic 

demand management tools, including road or congestion pricing, to more 

efficiently operate and manage their infrastructure. Pricing has the potential 

to reduce congestion by influencing drivers to carpool, use transit, or drive 

at off-peak travel times. Congestion pricing has, where evaluated, helped 

reduce congestion. However, it is difficult to draw overall conclusions about 

 

34As multiple years of safety data are needed to make conclusions, the current level of 

data is inconclusive. The UPA and CRD National Evaluation Framework will measure 

safety implications of pricing projects. As I-95 is a UPA site, data is being collected to 

evaluate safety changes due to the project. 

Concluding 

Observations
 

Page 32 GAO-12-119 Traffic Congestion 

the effectiveness of pricing because only half the sponsors with projects 

now open to traffic have evaluated their projects. Other results, where 

available, are mixed, as project sponsors have used different measures to 

assess performance and little has been done to compare performance 

across projects. Where congestion pricing projects have also added lanes, 

the results of pricing have not been distinguished from the results of adding 

capacity. Finally, congestion pricing’s impact on traveler behavior and 

equity has yet to be fully explored.

Congestion pricing in the United States is in its relative infancy. With 

about 400 miles of priced lanes in operation, which includes 150 miles of 

the New Jersey Turnpike, pricing has not been implemented beyond a 

limited number of locations. However, its popularity is growing. New 

projects under construction and in planning will not only increase the 

number of roadway miles that use congestion pricing, they will also 

change the character of pricing in the United States, as some will be 

operated privately and some will add congestion-priced tolls to previously 

nontolled roadways. The changing character of congestion pricing and 

the new challenges it brings make improving the understanding of 

congestion pricing even more important.

While a more complete understanding of the potential benefits and effects 

of congestion pricing is needed, we are not making a recommendation in 

this report because the evaluations conducted through the UPA and CRD 

programs are an important step to furthering understanding of the 

relevant benefits and effects of pricing. These evaluations of pricing 

projects address reservations we have about gaps in knowledge about 

such projects—for example, these evaluations will compare results 

across projects to assess the effectiveness of congestion reduction 

strategies and assess several measures of equity. In addition, monitoring 

and reporting on the five ELD projects could also provide better 

information about the performance of pricing and its effects. However, 

only one of the six UPA and CRD metropolitan sites has been evaluated 

and only for its first phase and four of the five ELD projects are under 

construction. As such, we cannot assess the evaluation framework or 

their results until projects and their evaluations are complete.
 

Page 33 GAO-12-119 Traffic Congestion 

DOT provided technical comments, which we incorporated as 

appropriate.

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. At that time, we will send copies of this report to 

congressional subcommittees with responsibilities for surface 

transportation issues and the Secretary of Transportation. In addition, this 

report will be available at no charge on GAO’s website at 

http://www.gao.gov. 

If you or your staff have any questions about this report, please contact 

me at (202) 512-2834 or herrp@gao.gov. Contact points for our Offices of 

Congressional Relations and Public Affairs may be found on the last page 

of this report. GAO staff that made significant contributions to this report 

are listed in appendix V.

Phillip R. Herr

Director, Physical Infrastructure Issues

Agency Comments
Appendix I: Objectives, Scope, and 

Methodology

Page 34 GAO-12-119 Traffic Congestion 

Our work was focused on the performance of congestion pricing projects 

on highways, bridges and tunnels in the United States and issues 

associated with developing and implementing pricing projects. We 

examined (1) the federal role in supporting congestion pricing, (2) results 

of congestion pricing projects in the United States, and (3) emerging 

issues in congestion pricing projects. Our scope was limited to assessing 

congestion pricing projects in the United States that involved passenger 

vehicles. We did not review other types of congestion pricing such as 

priced parking facilities. We collected information on pricing projects 

directly from the 19 project sponsors of the 41 operational or under 

construction congestion pricing projects and received comments and 

validation of data from project sponsors.

To address the federal role in supporting congestion pricing, we reviewed 

pertinent legislation and regulations; prior GAO reports and testimonies; and 

relevant documents from the U.S. Department of Transportation (DOT), state 

departments of transportation, and metropolitan planning organizations 

(MPO). This included policy documents from the Federal Highway 

Administration (FHWA) and various public presentations made by FHWA 

officials. We interviewed FHWA and Federal Transit Administration (FTA) 

officials, officials from state DOTs and MPOs, experts from academia and 

policy institutions, the Congressional Research Service (CRS), and the 

Congressional Budget Office (CBO). Our discussions with FHWA included 

DOT’s programs that involve tolling—Value Pricing Pilot Program (VPPP), 

High Occupancy Vehicle (HOV) Facilities, Express Lanes Demonstration, 

Section 129 program, the Interstate System Reconstruction and 

Rehabilitation Toll Pilot Program, and the Interstate System Construction Toll 

Pilot Program. We also discussed the Urban Partnership Agreement (UPA) 

and Congestion Reduction Demonstration (CRD) programs—one-time 

initiatives that were established with 10 separate federal grant programs. We 

discussed the eligibility and performance monitoring requirements of the 

federal programs and associated projects and verified this information with 

DOT documents. We also collected data of VPPP and UPA and CRD 

program funding from DOT and corroborated the status of the project data in 

interviews with FHWA. We analyzed the VPPP and UPA and CRD program 

funding to assess how federal funds are used to support congestion pricing 

projects. We interviewed sponsors of pricing projects that received federal 

funds on how the funds were used and with what results. We reviewed 

relevant FHWA environmental assessment manuals and interviewed FHWA 

officials about the environmental review process. We also interviewed FHWA 

field staff and project sponsors regarding their individual project’s 

environmental review process.

Appendix I: Objectives, Scope, and 

Methodology 
Appendix I: Objectives, Scope, and 

Methodology

Page 35 GAO-12-119 Traffic Congestion 

To determine the results of congestion pricing projects in the United States, 

we reviewed performance evaluation reports from eight project sponsors that 

covered 14 of the 30 operational pricing projects. The remaining project 

sponsors did not have current and completed evaluations because their 

projects had opened too recently for sponsors to have evaluated them or 

because projects had changed significantly in character since they were 

studied and thus the original evaluations are no longer relevant. In addition, 

one project evaluation did not use pre- and post-data to measure 

performance and thus the impact of pricing could not be measured. Two 

project sponsors (one sponsor of the SR 261, SR 241, and SR 133 in

Orange County, California and one sponsor of the SR 73 in Orange County, 

California) did not perform evaluations of their peak-period priced highways. 

Two project sponsors (one for I-15 in Salt Lake City, Utah, and one for I-10 

and US 290 in Houston, Texas) completed performance evaluations, 

however these three highways have significantly changed in character since 

then and thus the original evaluations are no longer relevant. For example, I15 in Salt Lake City currently uses electronic tolling with dynamic pricing 

whereas when the project was evaluated a monthly decal with a static toll 

was used. I-10 was evaluated as one HOT lane with free access of carpools 

of 3 passengers but is now 2 HOT lanes with free access for carpools of 2 

passengers. In addition, although US 290 was assessed in the I-10 

evaluation, no pre- and post-data were used to measure the impact of pricing 

on performance. The project sponsor of I-25 in Denver, Colorado reported on 

monthly counts of traffic volumes and other measures but did not do so 

before and after pricing was introduced; therefore, we were unable to use the 

data to compare with other projects. Three project sponsors (I-680 in 

Alameda County, California; the San Francisco-Oakland Bay Bridge in 

California; and MD-200 in Montgomery County, Maryland) implemented 

projects recently and have not had adequate time to evaluate the projects.1

 

1

According to the project sponsor, preliminary analysis comparing traffic counts between 

July and September 2009 and July and September 2010 found reduced traffic volumes. 

Traffic volume decreased by 8.4 percent in July and 7.3 percent in September during the 

a.m. and p.m. peak periods respectively. In September, traffic volume decreased by 6 

percent and 3.9 percent during the a.m. and p.m. peak periods respectively. A 

comprehensive evaluation study is under way. 

Three other projects—I-35 W in Minneapolis, Minnesota, which has the 

same project sponsor as I-394; SR 520 in Seattle, Washington, which has 

the same project sponsor as SR 167; and I-85 in Atlanta, Georgia—became 

operational recently and have also not been evaluated. I-35W, SR 520, and 

I-85 will be assessed as part of the UPA evaluations.
Appendix I: Objectives, Scope, and 

Methodology

Page 36 GAO-12-119 Traffic Congestion 

The eight project sponsors with current and completed evaluations we 

reviewed were I-95 in Miami, Florida; I-15 in San Diego, California; SR 91 

in Orange County, California; SR 167 in Seattle, Washington; I-394 in 

Minneapolis, Minnesota; the New Jersey Turnpike, New Jersey; two 

bridges in Lee County, Florida; and four bridges and two tunnels 

managed by the Port Authority of New York and New Jersey, New York. 

For each, we assessed the studies’ methodology to determine whether or 

not the data reported was valid and sufficient for our analysis. However, 

we did not conduct a thorough assessment of the quality of the 

evaluations’ methods as our objective was to assess the projects’ 

performance results where available. Once we determined which data 

was sufficiently reliable for our uses, we summarized the results reported 

in each performance evaluation for each project. The eight performance 

evaluations assessed various performance measures such as traffic 

speed, travel time, throughput, and transit ridership. The performance 

measures we focused our analysis on were: travel time and speed, 

throughput, off-peak travel, transit ridership, and equity. As a basis for 

assessing what performance measures we should review, we used a list 

of performance measures, some of which are outlined in the DOT’s UPA 

and CRD National Evaluation Framework. We chose these measurement 

areas because they were the most commonly reported in the evaluations 

and because they are the most commonly required measures for projects 

with federal monitoring requirements. We corroborated our choice of 

measures with FHWA and the Battelle Memorial Institute which is 

conducting the UPA evaluations using similar measures. We then 

compared the projects by qualitatively assessing the results for the five 

performance measures listed above and counting how many of the 

projects reported positive or negative results in each performance 

measurement category. We could not quantitatively compare results 

across projects because they did not use the same metrics and thus were 

assessed and reported differently according to project sponsor preference 

and resources. Project evaluations covered specific time periods and thus 

performance results are only for those time periods. Projects’ 

performance results may have changed since evaluations were 

completed.
Appendix I: Objectives, Scope, and 

Methodology

Page 37 GAO-12-119 Traffic Congestion 

Table 3: Evaluations and Surveys Used to Analyze the Performance and Effects of Congestion Pricing Projects 

Project name Location Evaluation

I-95 Miami, Florida 95 Express Midyear Report: Project Status for Urban Partnership 

Agreement. Florida Department of Transportation, October 30, 2009

Miami Urban Partnership Agreement (UPA) Project: Phase 1 Transit 

Evaluation Report Final. Florida Department of Transportation, 

January 2011

95 Express Annual Report: Project Status for Urban Partnership 

Agreement (Phase 1 Complete). Florida Department of 

Transportation, January 21, 2011

I-15 San Diego, California I-15 Congestion Pricing Project Monitoring and Evaluation 

Services—Task 13 Phase II Year Three Overall Report. San Diego 

Association of Governments, September 24, 2001

SR 91 Orange County, California Evaluating the Impacts of the SR 91 Variable-Toll Express Lane 

Facility: Final Report. State of California Department of 

Transportation, May 1998

Continuation Study to Evaluate the Impacts of the SR 91 ValuePriced Express Lanes Final Report. State of California Department of 

Transportation, December 2000

Lee County Bridges Lee County, Florida Lee County Variable Pricing Project: Evaluation Report. Lee County 

Variable Pricing Team, January 2001

I-394 Minneapolis, Minnesota I-394 MnPASS Technical Evaluation Final Report. Minnesota 

Department of Transportation, November 2006

MnPASS Evaluation Attitudinal Panel Survey Wave 3 Final Report.

Humphrey Institute of Public Affairs, University of Minnesota, August 

2006

Bridges and Tunnel Crossings New York-New Jersey Evaluation Study of Port Authority of New York and New Jersey Time 

of Day Pricing Initiative. New Jersey State Department of 

Transportation, March 2005

New Jersey Turnpike New Jersey Evaluation Study of New Jersey Turnpike Authority’s Time of Day 

Pricing Initiative Final Report. New Jersey Department of 

Transportation, May 31, 2005

SR 167 Seattle, Washington SR 167 HOT Lanes Pilot Project: Second Annual Performance 

Summary. Washington State Department of Transportation, May 

2008-April 2010

SR 167 HOT Lanes Social, Economic and Environmental Justice 

Report. Washington State Department of Transportation, January 

2007

SR 167 High Occupancy Toll Lanes January 2009 Focus Groups 

Final Report. Washington State Department of Transportation, 

March 4, 2009

SR 167 HOT Lanes Pilot Project Online User Survey. Washington 

State Department of Transportation, May 2009

Source: GAO analysis of current and completed evaluations of congestion pricing projects confirmed by project sponsors. 
Appendix I: Objectives, Scope, and 

Methodology

Page 38 GAO-12-119 Traffic Congestion 

We discussed with Battelle Memorial Institute, Texas Transportation 

Institute, and the Volpe National Transportation Systems Center the UPA 

and CRD evaluation framework including its performance measures and 

metrics as well as challenges of conducting an evaluation across multiple 

projects.

We also conducted site visits for the SR 167 and SR 520 projects in 

Seattle, Washington; I-95 project in Miami, Florida; and I-394 and I-35W 

in Minneapolis-St. Paul, Minnesota. We selected our site visits based on 

a judgmental sample of projects with completed evaluations; these sites 

included both HOT lanes and peak-period priced projects in different 

geographical areas of the United States. For each site visit, we met with 

relevant officials from state DOT, officials from the FHWA division office, 

project sponsors, and officials from local agencies such as the MPO and 

transit agencies. Discussion with project sponsors included clarifying the 

goal of the pricing projects and evaluations of the project performance. In 

addition to conducting interviews, we collected relevant documents, 

including environmental analyses, performance evaluations, and traveler 

surveys, and analyzed these documents as necessary. Where 

appropriate, we corroborated the interviews with documents obtained

from project sponsors and FHWA.

To identify the emerging issues in congestion pricing projects, we 

reviewed literature on congestion pricing, equity, environmental justice, 

traffic diversion, safety and other topics related to the benefits, costs, and 

trade-offs associated with congestion pricing. We reviewed prior GAO 

reports and analyses and reports from the FHWA, CRS, CBO, and 

industry experts and organizations that have evaluated the impacts of 

congestion pricing projects. We discussed our review of the reports with 

FHWA and FTA officials, officials from state DOTs and MPOs, and 

transportation experts from academia and think-tanks. We identified and 

interviewed experts with published work on congestion pricing and its 

impacts. Discussions with officials and experts included the costs and 

benefits of congestion pricing projects, trends in pricing designs and 

implementation, and methods to mitigate negative impacts. We also 

provided a copy of the draft report to a group of experts for an 

independent review. We selected these experts because they have 

published numerous studies analyzing the benefits and challenges of 

congestion pricing and its effects that are prominent in the transportation 

literature, and come from a cross section of institutions including 

academia, research organizations, and the private sector. We considered 

and incorporated their comments into the final report as appropriate.
Appendix I: Objectives, Scope, and 

Methodology

Page 39 GAO-12-119 Traffic Congestion 

Group of Experts that Reviewed Draft Congestion Pricing Report

Tod Litman, Researcher, Victoria Transport Policy Institute

Lee Munnich, Professor, Senior Fellow and Director, State and Local 

Policy Program, Hubert H. Humphrey School of Public Affairs, 

University of Minnesota

Robert Poole, Jr., Director of Transportation Policy, Reason Foundation

Joseph L. Schofer, Professor, Northwestern University

Brian Taylor, Professor of Urban Planning/Director, Institute of 

Transportation Studies, Luskin School of Public Affairs, UCLA 

David Ungemah, Senior Planning Manager, Parsons Brinckeroff

Martin Wachs, Senior Principal Researcher, RAND Corporation

We conducted this performance audit from October 2010 to January 2012 

in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our 

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.
Appendix II: Congestion Pricing Projects Open 

to Traffic in the United States, 2011

Page 40 GAO-12-119 Traffic Congestion 

Name Location

Number of facilities 

or miles

Type of 

project Type of pricing Toll rates

Date pricing 

operational

SR 91 Orange County, 

California

10 miles HOT lane Variable pricing $1.30-$9.75 December 

1995

I-15 San Diego County, 

California

16- miles (4-mile 

extension under 

construction)

HOT lane Variable pricing $0.50-$8.00 December 

1996

I-10 Houston, Texas 12 miles HOT lane Dynamic pricing $0.30-$1.60 January 

1998

Lee County 

Bridges

Lee County, Florida 2 bridges Bridge Peak-period 

pricing

$1.50-$6.00 (+ 

charge by axle)

August 1998

New Jersey 

Turnpikea New Jersey 148 miles Highway Peak-period 

pricing

$0.90-$9.05 September 

2000

US 290 Houston, Texas 15 miles HOT lane Peak-period 

pricing

$2.00 for HOV2 

users

November 

2000

Bridge and Tunnel 

Crossings 

New York-New Jersey 4 bridges and 2 

tunnels

Bridge and 

Tunnel

Peak-period 

pricing

$4.00-$8.00 March 2001

SR 73 Orange County, 

California

15 miles Highway Peak-period 

pricing

$3.95-$5.75 February 

2002

SR 261 Orange County, 

California

6.6 miles Highway Peak-period 

pricing

$1.30-$2.25 February 

2002

SR 241 Orange County, 

California

22.2 miles Highway Peak-period 

pricing

$2.10-$3.00 February 

2002

SR 133 Orange County, 

California

4.1 miles Highway Peak-period 

pricing

$1.60-$2.25 February 

2002

I-394 Minneapolis-St. Paul, 

Minnesota

11-miles HOT lane Dynamic pricing $0.25-$8.00 May 2005

I-25 Denver, Colorado 7-miles HOT lane Variable pricing $0.50-$4.00 June 2006

I-15 Salt Lake City, Utah 40 miles (11-mile 

extension under 

construction)

HOT lane Dynamic pricing $0.25-$1.00 September 

2006

SR 167 Seattle, Washington 9 miles southbound

11 miles northbound

HOT lane Dynamic pricing $0.50-$9.00 May 2008

I-95 Miami-Ft. Lauderdale, 

Florida

7 miles (15-mile 

extension under 

construction)

HOT lane Dynamic pricing $0.25-$7.00 December 

2008

I-35W Minneapolis-St. Paul, 

Minnesota

16 miles HOT lane Dynamic pricing $0.25-$8.00 September 

2009

Dulles Greenway Loudoun County, 

Virginia

14 miles Highway Peak-period 

pricing

$3.70-$4.50 January 

2009

Pocahontas 

Parkway 

Richmond, Virginia 8.8 miles Highway Peak-period 

pricing

$2.75-$3.00 January 

2011

Appendix II: Congestion Pricing Projects 

Open to Traffic in the United States, 2011
Appendix II: Congestion Pricing Projects Open 

to Traffic in the United States, 2011

Page 41 GAO-12-119 Traffic Congestion 

Name Location

Number of facilities 

or miles

Type of 

project Type of pricing Toll rates

Date pricing 

operational

San FranciscoOakland Bay 

Bridge 

San Francisco Bay 

Area, California

8 miles Bridge Peak-period 

pricing

$2.50-$6.00 July 2010

I-680 Alameda and Santa 

Clara Counties

14 miles HOT lane Dynamic pricing $0.30-$1.75 September 

2010

I-85 Atlanta, GA 15.5 miles HOT lane Dynamic pricing $1.55- 

$13.95

October 

2011

MD-200b Montgomery County, 

MD 

7 miles (in operation, 

11 are under 

construction)

Highway Peak-period 

pricing

$0.60-$1.45 November 

2011

SR 520 Seattle, Washington Bridge Bridge Variable pricing $0-$5.00 December 

2011

Source: GAO analysis.

a

The New Jersey Turnpike discontinued off-peak discounts to out-of-state vehicles as of July 2011. 

b

As of September 2011, 1 mile of MD 200 extension is under procurement. 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 42 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

1999 Orange County CA Managed 

Facility

Implementation of peak 

pricing on the SJHTC / 

SR 73

Study Completed $190,400 

 Orange County CA Managed 

Lanes

SR 91 evaluation Study Completed $314,762 

 Statewide MD Regional Feasibility of value pricing 

at 10 locations 

Study completed $687,536 

 Twin Cities MN Regional Regional study and 

outreach

Study and outreach 

completed

$778,800 

2000 San Diego CA Managed 

Lanes

Extension of I-15 HOT 

lanes 

Study completed $932,000 

 San Francisco CA Car Sharing Implementation and 

evaluation of car sharing

Implementation 

completed

$742,000 

 Santa Cruz CA Managed 

Lanes

HOT lanes on median of 

Route 1

Study completed $264,000 

 Lee County FL Managed 

Facility

Variable pricing of heavy 

vehicles 

Study completed $604,000 

 Lee County FL Managed 

Facility

Priced queue jumps Study completed $309,280 

 Miami-Dade Co. FL Managed 

Facility

Pricing options on Florida 

Turnpike

Study completed $696,320 

 Houston TX Managed 

Lanes

HOT lanes on three radial 

corridors 

Implementation 

completed

$2,436,000 

 Seattle WA Parking Parking cash-out Study completed $419,500 

2001 Orange County CA Managed 

Lanes

Variable tolls on SJHTC/ 

SR 73

Implementation 

completed

$344,800 

 San Diego CA Managed 

Lanes

Extension of I-15 HOT 

lanes

Study completed and 

project implemented

$28,000 

 San Francisco CA Car Sharing Carsharing Evaluation completed $378,186 

 Denver CO Managed 

Lanes

HOT lane on C-470 Study completed $500,000 

 Ft. Myers Beach FL Cordon Pricing Cordon pricing Study completed and 

implemented

$545,600 

 Lee County FL Managed 

Facility

Variable tolls for heavy 

vehicles

Implementation 

completed

$428,000 

 Atlanta GA Insurance Mileage-based insurance/ 

FAIR lanes

Implementation 

completed

$1,035,465 

 Statewide MN Variable Auto 

Costs

Variablization of fixed 

auto costs

Implementation 

completed

$1,050,931 

 New York metro 

area

NJ Managed 

Facility

Variable tolls on river 

crossings 

Evaluation completed $594,673 

Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 43 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

 Statewide NJ Managed 

Facility

Variable tolls on N.J. 

Turnpike

Evaluation completed $477,468 

 Statewide OR Regional Financing infrastructure 

with value pricing

Study completed $320,000 

 Philadelphia PA Managed 

Facility

Variable tolls on PA 

Turnpike

Study completed $776,000 

 Seattle WA Parking Parking cash-out and 

pricing

Implementation 

completed

$499,280 

 Seattle WA Cash-out of 

Cars

Cash-out of cars Implementation 

completed

$98,832 

2002 Alameda County CA Dynamic 

Ridesharing

Highway pricing with 

dynamic ridesharing

Study and 

implementation 

completed 

$595,250 

 Denver CO Managed 

Lanes

HOT lane on I-25 Implementation 

completed

$1,721,526 

 Broward County FL Managed 

Lanes

Variable tolls with open 

road tolling

Study completed $320,000 

 Ft. Myers Beach FL Cordon Pricing Cordon pricing Study completed $500,000 

 Statewide FL Regional Sharing of technology on 

pricing

Study completed $210,000 

 Statewide MN Regional Project development 

outreach

Study completed $950,000 

 Raleigh/Piedmont NC Managed 

Lanes

HOT lanes on I-40 Study completed $402,400 

 Portland OR Managed 

Lanes

HOT lanes on Hwy. 217 Study $400,000 

 Statewide OR Regional Financing infrastructure 

with value pricing

Study/Implemented $900,000 

 Philadelphia PA Managed 

Facility

Variable tolls on PA 

Turnpike

Implementation $800,000 

 Dallas-Ft. Worth TX Managed 

Lanes

HOT lanes on I-30 

/region-wide study

Study $152,000 

 Seattle WA GPS-Based 

Pricing 

GPS-based pricing Implementation $1,880,000 

2003 Denver CO Managed 

Lanes

HOT lane on I-25 Implementation $1,078,474 

 Lee County FL Managed 

Facility

Priced queue jumps Design $1,069,120 

 Miami-Dade Co. FL Managed 

Lanes

HOT lanes on I-95 Study $508,000 

 Chicago IL Managed 

Facility

Variable tolls on 

Northwest Tollway

Study $360,000 

 New York metro 

area

NJ Regional Express bus/HOT lane 

study

Study $670,033 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 44 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

 Statewide OH Regional Truck toll pricing study Study $200,000 

 San Antonio TX Managed 

Lanes

I-35 HOT lane study Study $160,000 

 Northern Virginia VA Regional HOT lanes regionwide Study $500,741 

2004 Alameda Co CA Managed 

Lanes

I-680 SMART Carpool 

Lanes

Study completed and 

project implemented

$714,000 

 San Diego CA Managed 

Lanes

Violation Enforcement on 

I-15 HOT Lanes

Study ongoing and 

technology not 

introduced

$699,772 

 Miami FL Managed 

Lanes

I-95 Managed Lanes 

Research and 

Educational Outreach

Study completed and 

early phase of 95 

Express 1st phase 

completed

$208,000 

 Orlando FL Managed 

Lanes

Express Lanes on I-4 Study cancelled $400,000 

 Atlanta GA Regional Pricing Atlanta’s 

Interstate System

Study completed and 

early phase of Atlanta 

CRD project though not 

implemented yet

$1,180,863 

 Atlanta GA Managed 

Lanes

Value Pricing on the I-75 

HOV/BRT Project

Study completed and 

pursuing 

implementation

$400,000 

 Minneapolis MN Managed 

Lanes

I-394 Pricing-Planning, 

Outreach and Education

Study completed and 

project implemented

$925,000 

 New York NY Managed 

Lanes

Express Bus/HOT Lane 

in Lincoln Tunnel

Study completed and 

considering 

implementation

$416,000 

 Statewide OR Mileage-Based 

Fee

Mileage-based Road 

User Fee

Feasibility study 

completed

$943,949 

 Dallas-Ft. Worth TX Managed 

Facility

I-30 Managed Facility 

Operational Plan

Study completed 

executed ELDP toll 

agreement thus 

pursuing

$472, 416

 Houston TX Managed 

Lanes

Houston HOT Network Study completed and 

seeking toll authority 

thus pursuing

$460,000 

 Seattle WA Managed 

Lanes

SR 167 HOT Lanes Study completed and 

project implemented

$1,180,000 

2005 Alameda Co CA Managed 

Lanes

I-680 SMART Carpool 

Lane in Alameda County

Study completed and 

project implemented

$950,000 

 San Francisco CA Cordon Pricing Area Road Charging and 

Parking Pricing 

Study completed but 

not pursuing 

implementation

$1,040,000 

 San Diego CA Managed 

Lanes

Violation Enforcement 

System on I-15 HOT 

Lanes

Study completed and 

project implemented

$568,678 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 45 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

 Atlanta GA Managed 

Facility

I -75 South Feasibility of 

HOT/Truck-Only Toll 

(TOT) Implementation

Feasibility study 

completed but not 

pursuing 

implementation

$242,388 

 Washington DC Managed 

Lanes

Regional Network of 

Value Priced Lanes

Feasibility study; 

elements being 

pursued for 

implementation

$240,000 

 Seattle WA Managed 

Lanes

State Route 167 HOT 

Lane Pilot

Study completed and 

project implemented

$880,000 

 Orange CA Managed 

Lanes

Implementation of 

Dynamic Pricing on SR 

91

Study withdrawn $588,000 

 Savannah GA Managed 

Facility

Northwest Truck Tollway Study completed but 

not pursuing 

implementation

$472,000 

 Austin TX Managed 

Lanes

Loop 1 HOT Lane Study completed and 

pursuing

$172,000 

 Austin TX Managed 

Lanes

Deliberative Polling-Loop 

I Corridor

Study completed $160,000 

 San Antonio TX Managed 

Lanes

IH-10 Value Priced 

Express Lanes

Study completed but 

not pursuing 

implementation

$129,600 

 Waco TX Managed 

Lanes

I-35 Value Priced 

Express Lanes

Study complete 

executed ELDP toll 

agreement and 

pursuing

$440,000 

 Lee County FL Managed 

Facility

Expansion of Value 

Pricing to the Sanibel 

Bridge and Causeway

Study cancelled $200,000 

 Atlanta GA Managed 

Lanes

GA-400 Variable Pricing 

Institutional Study

Study completed and 

project implemented

$444,000 

 Austin TX Managed 

Lanes

Truck Traffic Diversion 

Using Variable Tolls

Study withdrawn $148,000 

 Seattle WA GPS-Based 

Fee

Global Positioning 

System (GPS) Based 

Pricing Pilot Program

Feasibility study 

completed 

$600,000 

2006 NE Illinois IL Managed 

Facilities

Comprehensive Pricing in 

NE Illinois

Study completed and 

considering pricing in 2 

corridors 

$750,000 

 Santa Clara County CA Managed 

Lanes

Investigation of Pricing 

Strategies

Study completed 

pursuing VPPP toll 

agreement 

$760,000 

 San Diego CA Parking Priced Smart Parking 

Field Test

Study completed $640,000 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 46 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

 San Francisco CA Car Share City Car Share Pricing 

Innovations

Study completed $436,000 

 Riverside County CA Managed 

Lanes

Analysis of Environmental 

Effects of Pier Pass

Study completed $118,311 

 Tampa FL Car Share Dynamically-Priced 

Carsharing 

Study completed $331,289 

2007 Port Authority of 

New York and New 

Jersey 

NJ Managed 

Facilities

Upgrade of Electronic Toll 

Collection Technology

Study withdrawn $988,000 

 Puget Sound/Seattle 

Area 

WA Managed 

Lanes and 

Facilities

Puget Sound Tolling 

Strategies

Study completed but 

not pursuing 

implementation 

$935,000 

 Twin Cities MN Managed 

Lanes 

FAST Miles Study completed and 

project implemented

$60,000 

 Twin Cities MN Parking Parking Pricing 

Demonstration

Study completed $580,000 

 Twin Cities MN Mileage-Based 

Fee

Mileage-Based User Fee 

Regional Outreach

Study completed $230,000 

 Puget Sound/Seattle 

Area 

WA Insurance Pilot Implementation of 

PAYD Insurance with 

King County, Washington 

and Unigard Insurance 

Group

Study completed $1,900,000 

2007-2008a San Francisco Bay 

Area 

CA Parking SFPark Urban 

Partnership 

Feasibility study 

completed

$10,000,000 

 Minnesota 

Department of 

Transportation 

MN UPA MN Innovative Choices 

for Congestion Relief 

UPA

Study completed and 

project implemented

$5,000,000 

 Washington State 

Department of 

Transportation /King 

county/Puget Sound

WA UPA Seattle/Lake Washington 

Corridor Tolling and 

Transit UPA

Study completed and 

project will be 

implemented in April 

2011

$10,000,000 

2009 Caltrans/Valley 

Transportation 

Authority

CA Managed 

Lanes

Implement Roadway 

Pricing on SR 237 

Express Connectors

Pursuing toll authority 

to implement

$3,200,000 

 Twin Cities Area MN Managed 

Facilities

Feasibility Study on 

Pricing Innovative Lane 

Additions on Trunk 

Highway 77

Study withdrawn $540,000 

 Twin Cities Area MN Managed 

Lanes

Pre-Implementation 

Study of Priced Managed 

Lane on I-94

Study just started $400,000 

 Greater Buffalo 

Niagra Regional 

Authority

NY GPS-Based 

Fee

Pre-implementation of 

Study of GPS-Based 

Truck Pricing System

Study completed $717,000 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 47 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

 Puget Sound/Seattle 

Area 

WA Managed 

Lanes

Express Lanes System 

Concept Study

Study underway $1,280,000 

2009-2010 Caltrans / Santa 

Clara County

CA Parking Strategies to Manage 

Traffic and Parking 

Feasibility study 

underway

$2,358,000 

 Caltrans / City of 

Berkeley 

CA Parking Strategies to Manage OnStreet Parking and 

Reduce Congestion From 

Circling Vehicles.

Feasibility study 

underway

$1,800,000 

 Caltrans / Santa 

Barbara County

CA Carpool Testing of carpooling 

system that uses 

participation incentives

Feasibility study 

underway

$158,400 

 Florida Department 

of Transportation

FL Managed 

Lanes

Initiative for a Regional 

Priced Managed Lane 

Network that Can Serve 

as a Model for Other 

Regions

Feasibility study 

underway

$900,000 

 Tampa-Hillsboro 

Expressway 

Authority

FL Managed 

Lanes

Advancement of First 

Regional Network of Bus 

Toll Lanes in the Tampa 

Area 

Feasibility study 

underway

$800,000

 North Carolina 

Department of 

Transportation and 

Charlotte 

Metropolitan 

Planning 

Organization

NC Managed 

Lanes

Advancement of First 

Regional Network of 

Priced Lanes in the 

Charlotte Area 

Feasibility study 

underway

$400,000

 Minnesota 

Department of 

Transportation

MN Parking Expansion of Project to 

Test Incentive 

Alternatives to Monthly 

Parking Passes and 

Discourage Daily Driving

Feasibility study 

underway

$24,800

 Texas Department of 

Transportation

TX Insurance Usage-Based Insurance 

Pricing and Additional 

Incentives for Efficient 

Travel Choices

Feasibility study 

underway

$1,948,000

 Virginia Department 

of Transportation 

and Washington 

Council Of 

Governments

VA Managed 

Lanes

Advancement of Regional 

Pricing in DC Including 

Pricing Existing Facilities 

Feasibility study 

underway

$320,000

 Washington State 

Department of 

Transportation and 

King County

WA Parking Implementation of 

Incentives as Alternatives 

to Parking

Feasibility study 

underway

$1,024,000

Total awarded for Fiscal years 1999-2010 $92,702,843 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 48 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

2010-2011 California 

Department of 

Transportation 

CA Managed 

Lanes

Evaluate the application 

of cordon/area pricing 

within major activity 

centers in the downtown 

Los Angeles core and 

build out a network of 

HOT lanes

Approved for Funding $3,200,000

Connecticut 

Department of 

Transportation

CT Managed 

Lanes

Study the application of 

pricing on the I-84 

Viaduct, Hartford, CT 

including assessing the 

impacts of environmental 

justice issues that 

resulted from the original 

construction of the 

viaduct

Approved for Funding $644,000

Connecticut 

Department of 

Transportation

CT Managed 

Facility

Study the application of 

full facility pricing to the I95 Corridor from New 

York to New Haven, CT 

and identify how toll

revenues would be 

applied to provide strong 

support for transit

Approved for Funding $1,120,000

Florida Turnpike 

Enterprise

FL Managed 

Facility

Evaluate a two-tiered 

pricing on an existing toll 

facility and develop 

performance measures to 

track the changes in 

congestion, air quality, 

safety, livability and other 

factors that would result. 

Approved for Funding $600,000 

Illinois State 

Highway Tollway 

Authority

IL Managed 

Facility

Study will look at the 

application of pricing on 

an existing toll road and 

will evaluate steps to 

mitigate equity concerns 

for potential low income 

users. The project will 

also evaluate how transit 

could be integrated and 

financed through priced 

managed lanes

Approved for Funding $528,840
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 49 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

Dallas Area Rapid 

Transit

TX Managed 

Lanes

Study will look at a transit 

credit program designed 

to provide occasional free 

use of the HOT lane for 

regular transit users when 

they need to drive, and a 

parking pricing program 

at a park and ride lot with 

free parking and shuttle 

services added from a 

more distant lot. 

Approved for Funding $160,000

Texas Department of 

Transportation and 

North Central Texan 

Council of 

Governments

TX Managed 

Lanes

Influencing Travel 

Behavior and Considering 

Environmental Justice. 

Would examine important 

environmental justice 

issues related to pricing I30, through the use of 

innovative Intelligent 

Transportation Systems 

(ITS) technology. The 

project is important 

because it will provide 

more data on 

environmental justice and 

pricing, given that there is 

little experience with 

strategies designed to 

address environmental 

justice issues related to 

the introduction of pricing. 

This project was selected 

because it met the 

statutory eligibility criteria 

and was highly qualified 

for the above stated 

reasons. Therefore, this 

project meets the 

evaluation criteria for 

innovation, equity, and 

congestion reduction.

Approved for Funding $588,301 
Appendix III: DOT’s Value Pricing Pilot 

Program Grants, Fiscal Years 1999 through 

2010 

Page 50 GAO-12-119 Traffic Congestion 

Fiscal year Funding recipients State Project type Project Status Grant Amount

Texas Department of 

Transportation and 

Central Texas 

Regional Mobility 

Authority

TX Managed 

Facility 

183A Turnpike Pilot 

Downstream Impacts. 

Pilot implements a peak 

period toll in conjunction 

with dynamic ridesharing 

on an existing congested 

toll road. Would explore 

applying dynamic 

ridesharing as an equity 

mitigation strategy. An 

actual field trial is 

included as part of 

project. The road opens 

in 2012. The local 

agencies are contributing 

their own funds to support 

the project. Therefore, 

this project meets the 

evaluation criteria for 

innovation, livability, 

sustainability, equity, 

congestion reduction, 

safety and state of good 

repair. 

Approved for Funding $1,220,424 

Total approved for funding for Fiscal year 2010-2011 $8,061,565

Total awarded and approved for Fiscal years 1999-2011 $10,764,408

Source: U.S. Department of Transportation. 

a

Fiscal year 2008-2009 grants were part of the one-time Urban Partnership Agreement initiative. 
Appendix IV: Performance and Monitoring 

Requirements for Federal Programs for 

Congestion Pricing Projects

Page 51 GAO-12-119 Traffic Congestion 

Federal program Performance measure Performance metric

Performance 

and monitoring 

requirement

Express Lanes 

Demonstration

Travel-time reliability in 

priced lanes

• Report percentage of time facility is operating at a 

minimum average speed of 50 mph broken down by daily 

averages a.m. peak, off-peak, and p.m. peak hours. 

• Report 95th percent travel times for the managed lanes 

broken down by daily averages during a.m. peak, off-peak, 

and p.m. peak hours. The 95th percentile represents the 

slowest traffic day in each month and is reported in 

minutes. For the I-30 and I-35E projects in Texas, projects 

must also report the 80th percentile. 

• Report “Buffer Index” calculated to demonstrate 

performance in the managed lanes broken down by daily 

averages during a.m. peak, off-peak, and p.m. peak hours. 

The Buffer Index is the extra time that travelers must add

to their average travel time when planning trips to ensure 

on-time arrival. 

• Report travel volumes and traffic volume changes on a 

total and percentage-change basis annually broken into 

daily averages for daily total by a.m. peak, off-peak, and 

p.m. peak hours for the managed lanes by direction

• Traffic speeds and traffic speed differences from the 

previous year on a total and percentage-change basis 

annually broken into daily averages for daily total by a.m. 

peak, off-peak, and p.m. peak hours for the managed 

lanes by direction. 

• Report actual number of incidents and identify the effect 

on lane availability for the managed lanes during this time, 

including the length of time each such lane was 

unavailable. 

Annual reporting 

to U.S. DOT 

required.

Changes in mode 

split/ridership/vehicle 

occupancies of priced 

versus general purpose 

(or adjacent free) lanes

• Report number of declared High Occupancy Vehicles (HOV) 

for the year and differences from the previous year (on a total 

and percentage-change basis) broken into daily averages by 

a.m. peak and p.m. peak for the managed lanes.

• Report number of buses (i.e., registered non-revenue 

accounts) for the year and differences from the previous 

year on a total and percentage-change basis) broken into 

daily averages by a.m. peak, off-peak, and p.m. peak for 

the managed lanes. 

• Report average toll charged for the year and differences 

from the previous year (on a total and percentage-change 

basis), broken into daily averages, by a.m. peak, off-peak, 

and p.m. peak for managed lanes. 

Appendix IV: Performance and Monitoring 

Requirements for Federal Programs for 

Congestion Pricing Projects
Appendix IV: Performance and Monitoring 

Requirements for Federal Programs for 

Congestion Pricing Projects

Page 52 GAO-12-119 Traffic Congestion 

Federal program Performance measure Performance metric

Performance 

and monitoring 

requirement

• Report average toll charged for the year and differences 

from the previous year (on a total and percentage-change 

basis), broken into daily averages, by a.m. peak, off-peak, 

and p.m. peak for managed lanes. 

• If reasonably available, report ridership volumes for the 

year and differences from the previous year (on a total and 

percentage-change basis), by vehicle type: single 

occupancy vehicle, HOV2+, HOV3+, bus, vanpool and 

other, broken into daily averages by a.m. peak, off-peak, 

and p.m. peak for the general purpose lanes, managed 

lanes, and parallel access roads as applicable.

• Report on the amount of vehicle miles traveled for the year 

and differences from the previous year (on a total and 

percentage-change basis) by vehicle type: single 

occupancy vehicle, HOV2+, HOV3+, bus, vanpool and 

other, broken into daily averages by a.m. peak, off-peak, 

and p.m. peak on the managed lanes. 

• Report Metropolitan Planning Organization rideshare 

payments, HOV subsidy and other disbursements. 

Transit schedule 

adherence

• To the extent the information is reasonably available, 

report on transit service reliability—percentage of on-time 

performance of transit service. 

• To the extent the information is reasonably available, 

report on any existing bus transit routes or sanctioned 

vanpool accounts utilizing the corridor in advance of 

opening the project for tolling. This is to be used as a 

benchmark for added bus transit routes or sanctioned 

vanpool accounts utilizing the corridor after tolling begins. 

Application of revenue 

reinvestment

• Report breakdown of the use of revenue.

• Report percentage of revenue used to mitigate impacts. 

Change in criteria 

pollutant emissions at the 

regional level

• Report on the concentrations of six criteria pollutants 

(particle pollution, ground-level ozone, carbon monoxide, 

sulfur oxides, nitrogen oxides and lead) during the current 

year and differences from the previous year (on a total and 

percentage-change basis) utilizing reasonably available 

and reliable air quality reporting tolls and mechanisms. 

HOV Facilities 

(HOT Lanes)

Traffic speed on priced 

lane to maintain express 

bus service 

• Report a minimum average operating speed of 45 mph on 

the HOV lanes with a speed limit of over 50 mph or not 

more than 10 mph below the speed limit for HOV lanes 

with a speed limit less than 50 mph. This speed must be 

maintained for 90 percent of the time over 180 days during 

morning or evening weekday peak. 

Annual 

certification 

required by U.S. 

DOT. If 

performance 

standards not 

met, actions must 

be taken to 

comply.
Appendix IV: Performance and Monitoring 

Requirements for Federal Programs for 

Congestion Pricing Projects

Page 53 GAO-12-119 Traffic Congestion 

Federal program Performance measure Performance metric

Performance 

and monitoring 

requirement

Value Pricing Pilot Driver behavior, traffic 

volumes, and travel 

speeds

• No specific metric required No certification

required by U.S. 

DOT as no 

specific 

performance 

standards must 

be met. However, 

participants are 

required to report 

on “value pricing” 

elements up to 10 

years. 

Transit ridership • No specific metric required

Air quality • No specific metric required

Equity for low-income 

people

• No specific metric required

Transportation revenues • No specific metric required

Urban Partnership 

Agreement and 

Congestion 

Reduction 

Demonstrationa

Congestion Analysis • Percent change in route/corridor travel time by time of day

• Percent change in the travel time index for comparisons 

across sites (having corridors of differing lengths)

• Percent change in number of hours of the day with 

congested conditions and the number of congested travel 

links per day

• Percent change in average travel speeds by hour of the 

day

• Percent change in travel time reliability and planning time 

index

• Percent change in vehicle and person trips by time of day 

and person and vehicle throughput

• Change in traveler perceptions about congestion after 

deployment of strategies

Multi-year 

project-specific 

and national 

evaluations which 

U.S. DOT is 

overseeing.

Tolling Analysis • Level of service in tolled lanes

• Travel-time reliability in tolled lanes

• Average occupants per vehicle of tolled lanes versus 

general purpose lanes

• Use of tolling options

• Traffic density in tolled lanes

• Travel-time reliability (seasonally controlled)

• Days exceeding reliability and performance thresholds

Transit Analysis • End-to-end travel time

• Service reliability

• Maximum/unconstrained travel-time ratio

• Schedule adherence

• User ratings of service performance

• Corridor ridership

• Boardings/deboardings

• Service load factors

• Corridor mode split (%)

• Park-and-ride utilization factors
Appendix IV: Performance and Monitoring 

Requirements for Federal Programs for 

Congestion Pricing Projects

Page 54 GAO-12-119 Traffic Congestion 

Federal program Performance measure Performance metric

Performance 

and monitoring 

requirement

Equity Analysis • Socio-economic and geographic distribution of benefits 

including: tolls paid and adaptation costs; change in travel 

time and distance by group; total transportation cost; 

environmental impacts

• Public perception of the individualized equity impacts of 

pricing

• Spatial distribution of revenue reinvestment

Environmental Analysis • Reduction in criteria pollutants

• Reduction in noise

• Reduction in vehicle miles traveled

• Qualitative assessment of perceived benefits of the 

environment

• Reductions in estimated fuel use

• Use and impact of alternative fuel vehicles for transit 

improvements

Safety Analysis • Percentage change in crash rate by type and severity

• Percentage change in time to clear accidents

• Change in the perception of safety by service patrol 

operators, state patrol officers, medical first responders, 

and bus operators

• Change in the perception of safety by travelers

Source: GAO analysis. 

a

This is a sample of UPA and CRD performance analyses that include measures and metrics related 

to the effects of congestion pricing. Other UPA and CRD analyses will look at telecommuting/travel 

demand management and technology as well as impacts on businesses, goods movement, and 

nontechnical success factors. 
Appendix V: GAO Contact and Staff 

Acknowledgments

Page 55 GAO-12-119 Traffic Congestion 

Phil Herr, (202) 512-2834 or herrp@gao.gov

In addition to the contact named above, Steve Cohen (Assistant Director), 

Maureen Luna-Long, Sarah Jones, Thanh Lu, Michael Kendix, Sara Ann 

Moessbauer, James Wozny, Elizabeth Eisenstadt, Crystal Wesco, and 

Josh Ormond made key contributions to this report.

Appendix V: GAO Contact and Staff 

Acknowledgments 

GAO Contact

Staff 

Acknowledgments

(546029)
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