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entitled 'Surface Transportation: Strategies Are Available for Making 
Existing Road Infrastructure Perform Better' which was released on July 
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Report to the Ranking Member, Committee on Environment and Public 
Works, U.S. Senate: 

United States Government Accountability Office: 

GAO: 

July 2007: 

Surface Transportation: 

Strategies Are Available for Making Existing Road Infrastructure 
Perform Better: 

GAO-07-920: 

GAO Highlights: 

Highlights of GAO-07-920, a report to the Ranking Member, Committee on 
Environment and Public Works, U.S. Senate 

Why GAO Did This Study: 

For the past several decades, the capacity of the nation’s road network 
has not grown fast enough to keep pace with demand. The increasing 
congestion is apparent to millions of commuters and freight operators. 
Although road building is perhaps the most familiar antidote, Congress, 
the Department of Transportation (DOT), and transportation research 
have emphasized the need to more efficiently use the existing 
infrastructure as a means to control congestion. 

GAO was asked to examine various issues associated with increasing the 
efficient use of existing infrastructure. This report examines the 
following questions: (1) What factors inhibit the efficient use of the 
existing infrastructure of roads and highways? (2) What techniques have 
been developed for making the current infrastructure more efficient and 
what is known about the results? (3) How have local decision makers 
implemented these techniques? (4) What strategies exist for increasing 
the use of such techniques? To address these questions, GAO reviewed 
existing studies, examined efforts in five states, and sought 
transportation officials’ views, among other things. 

GAO is not making recommendations in this report. In commenting on a 
draft of this report, DOT provided technical clarifications, which we 
incorporated as appropriate. 

What GAO Found: 

Three broad factors inhibit efficient use of existing roads. First, 
many were not designed and built to meet today’s traffic volumes, and 
their operation has not changed sufficiently to better meet current 
volumes. Second, the federal and state revenue-raising structure does 
not provide incentives for drivers to use roads efficiently because it 
does not capture all the costs involved in using roads at time of peak 
demand. Third, information about which investments produce the highest 
estimated social benefits is limited when decisions are made about how 
to address congestion. 

Two types of techniques have been developed for making current roads 
more efficient. One enhances capacity through better operations and use 
of technology, such as timing traffic signals to improve traffic flow. 
The other influences behavior about when and where to drive, through 
such specific means as flexible work schedules, and charging drivers 
tolls to use roads during peak hours. Research suggests that these 
techniques are most effective when tailored to the particular situation 
and used in combination. 

In the states GAO reviewed, officials chose varying techniques but 
tended to implement them with a similar three-pronged approach: (1) 
changing planning and related processes to give these techniques more 
priority, (2) developing creative mechanisms to fund them, and (3) 
collaborating with multiple stakeholders to put them in place. 
Officials said many of the techniques, while helpful, provided only 
marginal benefits, because several persistent challenges prevented 
greater use. These challenges ranged from resolving jurisdictional 
authority to finding alternative funding sources. 

Although many strategies exist for making greater use of these 
techniques, they vary depending on the level of government involved. 
Three strategies cut across all levels of government: (1) considering 
how the private sector can be used in managing existing road 
infrastructure, (2) expanding the user-pay concept for managing demand 
and generating revenue for transportation investments, and (3) 
measuring results and managing with them in mind. Several other 
strategies, such as applying techniques on a regional basis and 
integrating transportation planning more fully with land-use planning, 
relate primarily to state and local governments. Strategies at the 
federal level, where participation in transportation projects relates 
primarily to financial assistance and policies affecting system 
performance and safety, includes linking federal funding to 
performance, increasing flexibility for states and localities, and 
placing additional focus on projects with national benefits. 

Figure: Examples of Various Congestion Mitigation Techniques: 

[See PDF for Image] 

Source: GAO. 

[End of figure] 

[Hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-07-920]. 

To view the full product, including the scope and methodology, click on 
the link above. For more information, contact JayEtta Z. Hecker at 
(202) 512-2834 or heckerj@gao.gov. 

[End of section] 

Contents: 

Letter: 

Results in Brief: 

Background: 

Three Broad Factors Inhibit Efficient Use of Roads: 

Various Techniques Have Been Developed to Make the Current 
Infrastructure More Efficient: 

Transportation Decision Makers Are Using Similar Approaches for 
Implementing Congestion Mitigation Techniques, but Challenges Exist: 

Various Strategies Exist for Increasing the Efficient Use of 
Infrastructure: 

Concluding Observations: 

Agency Comments and Our Evaluation: 

Appendix I: Objectives, Scope, and Methodology: 

Appendix II: Congestion Mitigation Techniques and Benefits: 

Appendix III: GAO Contact and Staff Acknowledgments: 

Tables: 

Table 1: Examples of Long-range and Short-range Transportation Plans at 
Locations GAO Visited: 

Table 2: Selected Congestion Mitigation Techniques That Enhance 
Capacity: 

Table 3: Select Congestion Mitigation Techniques That Influence Driver 
Behavior: 

Figures: 

Figure 1: Percentage Change of Vehicle Miles Traveled and New 
Construction of Lane Miles between 1980 and 2005: 

Figure 2: Representation of Levels of Service on a Two-Lane Highway: 

Figure 3: Percentage of Highway Capacity That Is Reduced When Vehicle 
Incidents Occur: 

Figure 4: Select Congestion Management Techniques that Enhance Capacity 
and Influence Driver Behavior and Demand: 

Figure 5: Express Lanes and General Purpose Lanes on State Route 91 in 
Orange County, California: 

Figure 6: Florida Road Ranger Incident Response Vehicle: 

Figure 7: Strategies for Making More Efficient Use of Existing 
Infrastructure: 

Figure 8: Representation of the VII Mobility Applications: 

Figure 9: Minnesota's "MnPass" Program: 

Abbreviations: 

DOT: Department of Transportation: 

FHWA: Federal Highway Administration: 

FTA: Federal Transit Administration: 

HOT: high-occupancy toll lane: 

HOV: high-occupancy vehicle: 

ICM: Integrated Corridor Management: 

ITS: intelligent transportation system: 

NCHRP: National Cooperative Highway Research Program: 

NTOC: National Transportation Operations Coalition: 

SAFETEA-LU: Safe, Accountable, Flexible, Efficient Transportation 
Equity Act: A Legacy for Users: 

TIP: Transportation Improvement Program: 

VII: Vehicle Integration Initiative: 

VMT: vehicle miles traveled: 

United States Government Accountability Office: 
Washington, DC 20548: 

July 26, 2007: 

The Honorable James M. Inhofe: 
Ranking Member: 
Committee on Environment and Public Works: 
United States Senate: 

Dear Senator Inhofe: 

Mobility--that is, the movement of passengers and goods through the 
transportation system--is critical to the nation's economic vitality 
and its citizens' quality of life. Mobility gives people access to 
goods, services, recreation, and jobs; gives businesses access to 
materials, markets, and people; and promotes the movement of personnel 
and material to meet national defense needs. While the transportation 
system that provides this mobility is made up of air, marine, and 
various modes of surface transportation, the nation's road network is 
the transportation system that most citizens use daily. It is also the 
critical pathway for the movement of freight. 

For the past several decades, the capacity of the national road network 
has not grown fast enough to keep pace with the growing demand. 
Population, income levels, and economic activity have risen 
considerably and with them have come significant increases in travel 
demand and freight movement on the surface transportation system. The 
result is apparent to millions of commuters and freight operators: 
increasing number of hours spent inching along clogged roads and 
highways, especially at rush hours and other times of peak demands. The 
economic implications are significant, ranging from wasted fuel and 
time as cars idle in traffic to increased logistics costs for business 
as the unreliability of the systems grows. While building additional 
roads is perhaps the most familiar way for addressing congestion, 
Congress, the Department of Transportation (DOT), and transportation 
research have emphasized the need to more efficiently use the existing 
infrastructure as a means to help control congestion. This could be 
done both by managing the existing network to enable it to handle more 
traffic and by managing the demands placed upon it. However, 
transportation stakeholders and experts have generally acknowledged 
that we are not using the existing infrastructure as efficiently as 
possible. For example, in its National Strategy to Reduce Congestion on 
America's Transportation Network, DOT notes that "at its most 
fundamental level, highway congestion is caused by the failure to 
develop mechanisms to efficiently manage use of existing capacity and 
expand capacity at locations were the benefits are the greatest. 
Although more efficiently using existing infrastructure is intended to 
help manage congestion, the goal of such efforts is not to completely 
eliminate or prevent congestion. 

Given the importance of the nation's road network, the federal 
government has partnered with states in developing and maintaining it. 
In recent years, the Federal Highway Administration (FHWA) has provided 
nearly $34 billion each year to states to build and improve roads and 
bridges and meet other transportation needs. Since transportation 
research and our work has indicated that the current system will not be 
able to meet future demand, you asked us to provide information on 
several key questions related to what is being done--and what else 
might be needed--in adjusting to this changing environment and ensuring 
our nation's mobility. More specifically, this report addresses the 
following questions: 

1. What factors inhibit the efficient use of the existing 
infrastructure of roads and highways? 

2. What techniques have been developed for making the current 
infrastructure more efficient and what is known about the results of 
these techniques? 

3. How have local decision makers implemented these techniques? 

4. What strategies exist for increasing the efficient use of existing 
infrastructure? 

To address these questions, we conducted a review of relevant 
literature, reports, studies, and our prior research and interviewed 
federal, state, and local transportation officials, as well as 
representatives from various industry associations with experience in 
developing, implementing, or analyzing these techniques. We also 
conducted site visits or interviews with state and local transportation 
officials in California, Colorado, Florida, Virginia,[Footnote 1] and 
Washington. We selected this nongeneralizable sample of states based on 
the level of congestion of selected metropolitan areas within these 
states, including Denver; Northern Virginia; Orlando; San Diego; San 
Francisco/San Jose/Oakland; and Seattle; and additionally on the 
states' experience with using congestion mitigation techniques to 
achieve geographical diversity. We also visited Aurora and Boulder, 
Colo; Altamonte Springs, Fla; Hampton Roads, Va; and Bellevue and 
Issaquah, Wash., to gain some insight into the implementation of 
congestion management techniques in smaller jurisdictions. During these 
site visits, we interviewed federal, state, and local transportation 
officials and toured operations centers. In addition, we reviewed 
studies and documentation on how these and other metropolitan areas and 
states have implemented congestion management techniques and their 
results. We conducted our work from September 2006 through July 2007 in 
accordance with generally accepted government auditing standards. (See 
app. 1 for more information about our objectives, scope and 
methodology.) 

Results in Brief: 

Three broad factors inhibit efficient use of roads and highways: design 
and operation factors; the revenue-raising structure; and a limited 
focus on selecting projects that produce the highest net social 
benefits in the current decision-making process. First, many roads were 
not designed and built to meet current traffic volumes, and operational 
changes--such as the timing of traffic signals--have not changed 
sufficiently to cope with the increased use. Second, the federal and 
state transportation revenue-raising structure, which collects the 
majority of revenues through motor fuel taxes and other user fees, does 
not provide incentives for drivers to take into account the external 
costs, such as increased travel time for other drivers, they impose in 
deciding when, where, and how to drive. For example, the tax rate on 
gasoline is the same regardless of whether drivers drive in congested 
or uncongested periods. Third, there is a limited focus in the current 
decision-making process on selecting projects that will produce the 
highest net social benefits. Decision makers also are limited in their 
ability to identify and put in place infrastructure investments that 
would produce the highest estimated social benefits because the current 
decision-making process is compartmentalized by mode and is not driven 
by economic analysis. 

Two categories of congestion mitigation techniques have been developed 
to improve the efficiency and better optimize the performance of the 
existing infrastructure. The first category includes techniques that 
enhance road capacity through better operations, such as incident 
response vehicles that quickly restore traffic flow after vehicle 
crashes, or the deployment of transportation technology, such as 
optimizing the timing of traffic signals to improve traffic flow. The 
second category includes techniques designed to better acknowledge the 
impact of using the road system during times of peak demand; these 
techniques influence drivers to make alternative choices, such as car 
pooling or shifting trips to less congested times. Studies and 
evaluations of projects indicate that these congestion mitigation 
techniques have the potential to provide benefits such as reduced 
congestion delays and improved traffic flows that maximize existing 
capacity. These studies and evaluations also indicate such techniques 
are most effective when tailored to the particular situation and used 
in combination. 

At locations we reviewed, officials chose varying congestion mitigation 
techniques but tended to implement them with a similar three-pronged 
approach: (1) changing planning and related processes to give them 
higher priority, (2) developing creative mechanisms to fund them, and 
(3) collaborating with multiple stakeholders to put them in place. For 
example, in considering which projects to select for funding, the 
metropolitan planning organization for the Denver region now awards 
points to projects that use certain congestion mitigation techniques, 
such as installing left-turn lanes, coordinating traffic lights, or 
managing incidents. Officials for the Denver region said they hope 
awarding points will provide incentives for local planners to include 
such techniques in their projects. Transportation officials said the 
mode-specific, "stove-piped" funding structure for transportation 
projects, together with a general lack of resources for transportation 
projects, constrained their ability to use these techniques. As a 
result, they said, they often have had to find alternative methods to 
supplement traditional funding sources. Officials also reported working 
with multiple partners to implement congestion mitigation techniques. 
They said the success of these techniques depends on coordination among 
many partners. While officials said the techniques produced benefits, 
these officials also called attention to various challenges that tended 
to preclude wider use. These challenges ranged from resolving 
jurisdictional authority to identifying sufficient funding to allow 
implementation on a broader scale. As a result, they said, the approach 
they used to implement these techniques could provide only marginal 
improvement to the efficiency of the road network. 

Various strategies exist for increasing the efficient use of 
infrastructure. We grouped the strategies by the level of government 
best suited to consider and implement them, given their current 
authorities, roles, and responsibilities. In some cases, all levels of 
government would need to be involved in implementing the strategy; in 
other cases, the federal government or a state government would be most 
appropriate to implement the strategy. We identified three strategies 
that cut across all levels of government, including (1) considering how 
the private sector can be used in managing existing road 
infrastructure, (2) expanding use of the user-pay concept for managing 
demand and generating revenue for transportation investments, and (3) 
developing a systematic performance-based management approach to 
increase the accountability of public expenditures and to link 
performance to investment decisions. We also identified strategies that 
would be most appropriate for state and local governments to consider, 
including applying congestion mitigation techniques on a regional basis 
and fully integrating transportation and land-use planning. For 
example, traffic signal timing is one technique that can provide 
significant benefits to drivers by providing for the smooth flow of 
traffic along streets and highways. To fully enhance mobility, 
jurisdictions need to coordinate the timing along an entire corridor, 
which often crosses multiple jurisdictions. Finally, we identified 
strategies that the federal government could consider to help increase 
the efficient use of infrastructure. These strategies include (1) 
linking funding more directly to performance, (2) increasing the 
flexibility provided to state and local governments to promote 
innovative solutions, and (3) focusing on projects (or transportation 
corridors) of national interest. For example, the federal government 
could also use incentives to link funding to particular outcomes, such 
as encouraging state and local governments to increase the efficient 
use and performance of existing infrastructure. According to 
transportation research and transportation officials and experts we 
interviewed, the strategies are not mutually exclusive and ideally 
would be implemented in a comprehensive manner. 

DOT, including FHWA, reviewed a draft of this report. DOT officials 
provided technical clarifications, which we incorporated as 
appropriate. 

Background: 

Pressure on Road System Continues to Build: 

Road usage, as measured by vehicle miles traveled (VMT), has grown over 
the last 25 years. From 1980 through 2005, the most recent years for 
which data are available, road usage grew at an average annual rate of 
2.7 percent from 1980 through 2005. A number of demographic and 
economic trends contribute to this increase in road usage, including 
the shift from urban to suburban areas by businesses and households, 
rising household incomes, and a greater reliance on trucks to move 
freight. For example, research shows that car ownership and VMT rise 
with income. The average U.S. household income (in 2005 dollars) grew 
from $47,263 in 1980 to $63,344 in 2005, according to U.S. Census 
Bureau data, fueling the number of cars on the road and the number of 
miles traveled. 

Increasing road usage has led to growing congestion in the nation's 
transportation system. In 2006, FHWA reported that congestion on U.S. 
highways between 1982 and 2003 had increased in extent, duration, and 
intensity. For example, in the largest U.S. cities, 67 percent of 
travel was impacted by congestion--up from 33 percent in 1982. As a 
result, drivers in urban areas are increasingly experiencing what FHWA 
calls recurring congestion, which is congestion that occurs day-in and 
day-out, such as slowdowns that occur during morning and afternoon 
commutes, even when road and weather conditions are ideal. This type of 
congestion occurs simply because so many cars and trucks are trying to 
use the road at the same time; the network as currently designed and 
operated simply cannot handle the volume. The imbalance between demand 
and supply also affects the network's ability to recover from what FHWA 
refers to as nonrecurring congestion, which is caused by crashes, 
weather, construction, or other event-driven variability. The increased 
volume of traffic often exacerbates the effects of such slowdowns and 
roadblocks in traffic flow. Both categories of congestion can lead to 
significant loss of productivity with real economic impacts. For 
example, the Texas Transportation Institute estimates that U.S. drivers 
experienced 3.7 billion hours of travel delay and wasted 2.3 billion 
gallons of fuel in 2003 due to congestion in the top 83 urban areas. 
The Texas Transportation Institute projected the total cost at $63 
billion (in 2003 dollars). In addition to the economic effects, 
congestion can also lead to negative environmental impacts. For 
example, studies have shown potential negative health effects from 
living near busy roads, with one recent study showing that children in 
neighborhoods with higher levels of traffic pollutants have shown an 
increased prevalence of asthma and bronchitis symptoms.[Footnote 2] 

Capacity Has Not Kept Pace with Demand, and Is Not Likely to Do So: 

Several strategies exist for addressing the growing congestion on 
roads, including constructing new infrastructure to add capacity, 
improving maintenance on existing capacity, and managing existing 
capacity through operational methods. While building new capacity is 
still a viable strategy in certain situations, such as in areas where 
there is available space to accommodate new roads or to add more lanes 
to existing roads, overall, the construction of new capacity is not 
keeping pace with the growing demand. For example, while VMT has almost 
doubled from 1980 to 2005, growing at an average annual rate of 2.7 
percent, during the same time, new construction of lane miles increased 
capacity at an average annual rate of 0.2 percent, so that by 2005 
total capacity was only 6 percent greater than in 1980. (See fig. 1.) 

Figure 1: Percentage Change of Vehicle Miles Traveled and New 
Construction of Lane Miles between 1980 and 2005: 

[See PDF for image] 

Source: GAO analysis of highway statistics from FHWA. 

Note: Index = 1 for 1980. 

[End of figure] 

Many factors appear to have contributed to the slow increase in supply 
relative to demand, with the several listed below often cited as most 
critical. 

* The purchasing power of available funding for highway construction 
and maintenance is declining. Although transportation revenues have 
continued to increase in nominal terms, with total highway revenues for 
states growing an average of 3.6 percent per year between 1995 and 
2004, the federal and state motor fuel tax rates--the mainstay of state 
highway revenue--have not kept up with inflation. According to DOT and 
FHWA data, this has resulted in a decline in the purchasing power in 
real terms of revenues generated by federal and state motor fuel tax 
rates since 1990. 

* An increasing proportion of available funds is being spent to 
preserve existing infrastructure. State and regional transportation 
decision makers are devoting more funding to highway investments that 
preserve, enhance, and maintain existing infrastructure than to 
investments that add capacity. Existing infrastructure is aging and 
keeping it functional is becoming more expensive. According to FHWA 
data, of the $70.3 billion spent nationally in 2004 on highway capital 
spending, 52 percent ($36.4 billion) was spent on system preservation, 
compared with 39 percent ($27.5 billion) for new construction.[Footnote 
3] In 1993, 45 percent of the total was spent on system preservation. 

* The recent growth of road construction costs exceeds the overall rate 
of inflation. The cost of building new capacity and maintaining 
existing capacity has increased steadily over the last few years, at a 
rate that exceeds inflation. The composite bid price index[Footnote 4] 
for highway construction has almost doubled since 1987, according to 
FHWA. In particular, the price of construction materials has increased 
significantly in the last few years because of rising diesel and 
asphalt prices. 

* Road-building solutions are becoming less popular. In many locations, 
the public has grown increasingly resistant to carving out additional 
space for roads, both for environmental and for social reasons. As a 
result, state and local governments have increasingly identified 
quality of life and environmental sustainability as key principles in 
their long-term regional plans for managing growth and investing in 
transportation infrastructure. Transportation planners will have to 
make trade-offs between facilitating increased mobility--through adding 
new road capacity--and giving due regard to environmental and other 
social goals. 

Building new infrastructure to keep pace with demand may continue to be 
problematic in the future, because revenues from the Highway Trust 
Fund--the major source of federal highway and transit funding--are 
projected to continue to erode in real terms due to inflation. 
Additionally, funding authorized in the most recent highway and transit 
program legislation is expected to outstrip the growth in trust fund 
receipts. According to recent estimates from the Congressional Budget 
Office and the President's budget, the trust fund balance will steadily 
decline and reach a negative balance of more than $14 billion by the 
end of fiscal year 2012.[Footnote 5] The overall fiscal imbalance the 
nation faces makes it difficult to find an easy fix for this problem by 
seeking to significantly expand federal contributions. As a result, in 
2007, we placed financing of the nation's transportation infrastructure 
on our list of high-risk issues facing federal decision 
makers.[Footnote 6] 

With Capacity Constrained, Other Approaches Are Receiving More 
Attention: 

Given these trends, state and local governments are turning to the 
other tools to manage congestion, including improving the efficiency of 
the existing road network. When considering how to better manage 
existing road infrastructure, two key concepts are important and will 
be referred to often in this report: maximizing the flow of vehicles 
and promoting efficient use of the road through users' choices. 

* Maximizing the flow of vehicles. This concept deals with achieving 
maximum flow of vehicles through a stretch of highway. Once a road 
reaches a certain capacity level, drivers' ability to travel at or near 
the posted speed limit begins to decrease, because traffic flow is 
increasingly affected by such things as an inability to change lanes to 
pass slower vehicles or a need to slow down to allow merging vehicles 
to enter. Transportation research uses "level of service"[Footnote 7] 
to measure the speed and travel time, freedom to maneuver, traffic 
interruptions, and comfort and convenience for a road. As figure 2 
shows, level of service ranges from "free flow," where the amount of 
traffic is small enough to allow travel at the posted speed limit, to 
"stop and go flow," where a road has become so packed with vehicles 
that drivers' speeds can fall to far lower than the speed limit. When 
the number of vehicles approaches maximum capacity, speeds are slowed 
to the point that a road can accommodate fewer total vehicles in a 
given period of time. As the figure shows, a road is considered to have 
a "stable flow" when the number of vehicles represents between roughly 
50 to 85 percent of the road's maximum carrying capacity. 

Figure 2: Representation of Levels of Service on a Two-Lane Highway: 

[See PDF for image] 

Source: GAO analysis of the Transportation Research Board of the 
National Academies Highway Capacity Manual. 

[End of figure] 

* Promoting efficient use through users' choices. This concept deals 
with ensuring that road users make choices about when to drive based on 
the full costs of using the road. Economists see congestion as a 
byproduct of drivers' decisions to use a specific road based only on 
the benefits they receive and the costs that they incur (for example, 
the gasoline they use and the time they spend) and not on the external 
costs they impose on others, such as increased travel time for others 
and increased pollution.[Footnote 8] From an economic perspective, a 
road is not efficiently "priced" when this condition occurs. To achieve 
more efficient use, some type of pricing mechanism, such as a toll or 
surcharge, would need to be implemented to take into account the cost 
that a driver imposes on others when using a congested road. Efficient 
road pricing is basically seen as a way to ration limited resources-- 
for example, the use of a highway during times of peak demand, such as 
rush hour. A toll or surcharge, under such conditions, would create 
incentives for drivers to shift their travel to periods of lower 
demand, use other roads, or make other adjustments, when the costs of 
their decision to drive during congested periods exceed the benefits 
they receive. 

Although more efficiently using existing infrastructure is intended to 
help manage congestion, the goal of such efforts is not to completely 
eliminate or prevent congestion. For example, an exorbitantly priced 
toll on a road that discourages drivers from using it would create an 
inefficient use of the infrastructure--even though there would be no 
congestion on the road. Similarly, a road network that could disperse a 
crowd of 90,000 from a football game and create no congestion would 
require many lanes that would likely be underused at all other times of 
the year. Economic efficiency is thus a balancing act. 

Congress has recognized the importance of improving the efficient use 
of the existing road infrastructure through the passage of Safe, 
Accountable, Flexible, Efficient Transportation Equity Act: A Legacy 
for Users (SAFETEA-LU). SAFETEA-LU addresses both current and future 
challenges facing our nation's transportation system by promoting 
efficient and effective federal surface transportation programs. In 
particular, SAFETEA-LU establishes new requirements and programs to 
promote the efficient use of existing infrastructure. For example, 
SAFETEA-LU requires that DOT establish a real-time system management 
information program to build the capability to monitor, in real time, 
the traffic and travel conditions of major highways and to share this 
information with state and local governments to assist in relieving 
congestion and providing traveler information. According to FHWA 
officials, a notice of proposed rule making for this program is 
expected to be published in late 2007. 

Federal Government Is One of Many Stakeholders in Operating and 
Managing the Road Infrastructure: 

Multiple stakeholders are involved in the construction, maintenance, 
and operation of the nation's road infrastructure. These stakeholders 
include the federal government, state and local governments, and the 
private sector. 

* The federal government, primarily through FHWA and the Federal 
Transit Administration (FTA), provides funding to state and local 
governments for road and transit infrastructure, establishes 
legislation and regulations that influence the performance and safety 
of the system, and administers transportation programs that cover a 
range of areas. 

* On the front lines of transportation decision making, state and local 
governments, through departments of transportation and metropolitan 
planning organizations, develop transportation plans and improvement 
programs, establish transportation funding mechanisms and build, 
maintain, and operate transportation infrastructure and services. 

* The private sector, when contracted by federal, state, or local 
governments, may build new roads, provide maintenance on existing 
roads, and supply traffic management equipment and, in recent models, 
design, finance, build, operate, and maintain the roads. 

In general, the federal government leaves many of the decisions about 
specific projects to states and localities, but it partners with these 
other levels of government in overall planning and administration, as 
well as funding the projects. The current framework for federal 
participation is set forth in authorizing statutes, most recently 
amended by SAFETEA-LU. SAFETEA-LU also amended certain requirements 
governing the way states and local governments plan and decide upon 
transportation projects. For example, the requirements describe various 
planning tasks that states and metropolitan planning organizations must 
perform to include (1) developing long-and short-range transportation 
programs and plans, (2) specifying financing for the transportation 
programs and projects identified, and (3) involving a wide range of 
stakeholders in the process that emphasizes cooperation and 
coordination. State and local government agencies must operate within 
the requirements set forth by SAFETEA-LU to receive federal funds. 

Three Broad Factors Inhibit Efficient Use of Roads: 

Three broad factors limit efficient use of the road network. First, the 
design and operation of existing road networks fail to adapt to 
changing uses. Second, the traditional funding structure does not 
provide incentives for the efficient use of roads. Third, the current 
investment decision-making process has a limited focus on selecting 
projects that may produce the highest net social benefits. 

Road Network's Design and Operation Fail to Adapt to Changing Uses: 

It is increasingly apparent that a considerable part of the nation's 
road network, particularly in urban areas, was neither designed and 
built to meet today's traffic volumes, nor has its operation changed 
sufficiently to better meet current usage patterns. 

* Problems with design. A road's design, which may have been adequate 
for a lower level of use, can create problems as traffic volumes 
increase. For example, existing exit and entrance ramps on freeways may 
be very short, allowing exiting vehicles little distance to move out of 
a fast-moving lane of traffic and allowing entering vehicles little 
distance to accelerate to highway speed. When the traffic volume is 
low, drivers exiting and entering the freeway may have ample time to 
shift lanes and maintain or increase speed, but as traffic volume 
increases, they may be unable to do so. As a result, the interchange 
can become a choke point. Similarly, some older roads do not have 
separate lanes for left-turning traffic at the intersection and, at 
peak hours, drivers making left turns can block considerable traffic 
behind them. 

* Problems with operations. Growing populations, longer trips, and 
other demographic and socioeconomic trends have contributed to changes 
in traffic volume and driving patterns, but operation of the road 
system has not necessarily changed to deal with these volumes or 
patterns. For example, because each local jurisdiction generally 
manages and operates its own streets, it may not have incentives to 
coordinate the timing of traffic signals on roads that cross many 
jurisdictions. As a result, the timing of traffic signals on these 
corridors may not operate in such a way to minimize the number of stops 
a driver would have to make. At peak hours, as traffic volumes 
increase, more traffic backs up at each stop, and traffic flow breaks 
down, creating a significant source of delay for drivers in their daily 
use of the major street system. 

Moreover, when a temporary disruption on the road occurs, these design 
and operation problems can hamper a road's ability to recover quickly. 
There are three main types of temporary disruptions--vehicle incidents, 
weather-related events (such as heavy rain), and work zones.[Footnote 
9] These temporary disruptions, which can cause congestion even on a 
road with low traffic volume, can grind the traffic on a whole road 
network to a halt if they occur on roads that already have design 
problems such as no left-turn lanes, or operational problems such as 
poorly timed traffic signals. According to FHWA, these three types of 
temporary disruptions account for about 50 percent of all congestion 
delays, with 25 percent of all delays related to vehicle incidents, 15 
percent to weather, and 10 percent to work zones. As figure 3 shows, 
the impact of a vehicle incident is magnified depending on how much of 
a roadway is affected. Compounding the effect, local transportation 
agencies often do not have an effective protocol to share information 
quickly and may lack a coordinated approach to manage such incidents, 
such as who is responsible for clearing an accident, and how to do so. 
The difficulty of predicting the effect that such incidents will have 
on the time it takes shipments to traverse the road network can also 
induce freight operators to factor additional time into their schedules 
or businesses into warehousing additional inventory, thereby increasing 
the cost of conducting business. 

Figure 3: Percentage of Highway Capacity That Is Reduced When Vehicle 
Incidents Occur: 

[See PDF for image] 

Source: GAO analysis of FHWA information. 

Note: The percentages are estimates for three-lane highways only and 
may vary with actual circumstances. 

[End of figure] 

Traditional Funding Structure Does Not Provide Incentives for Efficient 
Use of Roads: 

The federal and state transportation revenue-raising structure, which 
collects the majority of revenues through fuel taxes and other user 
fees, does not convey to drivers the full costs of their use of the 
road. These taxes and fees---such as fuel taxes or sales taxes--are not 
tied to the time when drivers actually use the road or which road they 
use. For example, the tax rate on gasoline is the same regardless of 
whether users drive in congested or uncongested periods. Except for 
these taxes and fees, drivers may generally perceive the use of the 
road as "free." However, the use of roads during congested periods can 
impose a variety of costs on other drivers and the society at large, 
such as the following: 

* When drivers enter an already crowded road, this creates even longer 
delays for everyone and thus an additional cost for everyone in loss of 
valuable time stuck in traffic. 

* Drivers may more likely get into an accident on a congested road. The 
greater potential of an accident occurring may create more uncertainty 
in predicting travel time, increasing costs for the traveling public 
and businesses because they need to schedule additional time to allow 
for possible delays. 

* Research shows that vehicles emit substantially more air pollution 
per mile when driven in congested traffic than in uncongested 
situations, which is a cost to society and is borne more heavily by the 
public living near the congested corridors. 

The existing revenue-raising structure provides no incentive for users 
to take these costs into account when making their driving decisions. 
From an economic perspective, a mechanism is needed that gives users 
price incentives to consider these costs in deciding when, where, and 
how to drive. Because the existing structure does not reflect the 
economic, social, and environmental costs of driving at peak periods, 
drivers who may have flexibility to share rides, use mass transit, use 
more indirect but less congested routes, or defer their trips to 
uncongested times have no financial incentives to do so. Without such 
incentives, the transportation system will be headed for more frequent 
occurrences of congestion that last longer, resulting in more time 
spent traveling, greater fuel consumption, and higher emissions in the 
long run. 

Current Investment Decision-Making Process Has a Limited Focus on 
Selecting Projects That May Produce the Highest Net Social Benefits: 

The final factor inhibiting efficient use of the road network relates 
to the ability to identify--and put in place--infrastructure 
investments that are most likely to be efficiently used. Making the 
best use of scarce resources for transportation infrastructure requires 
a process that allows decision makers to identify which investments 
would produce the highest net social benefits; however, this 
information is limited in the current decision-making process. Two 
characteristics inhibit decisions on this basis. Specifically, the 
current process is highly compartmentalized by transportation mode and 
is not driven by systematic economic analysis. Both characteristics, as 
explained below, can lead to investment decisions that, from the 
standpoint of making the transportation network as efficient as 
possible, produce suboptimal results. 

* Funding is compartmentalized by transportation mode. Many 
transportation experts maintain--and our past work[Footnote 10] tends 
to confirm--that the current structure of funding at the federal and 
state level is highly compartmentalized, or stove-piped. Funding is 
often tied to certain programs or types of projects, such as highways 
or transit, and it has also been increasingly designated for specific 
local uses.[Footnote 11] This structure provides state, regional, and 
local agencies with little incentive to systematically compare the 
trade-offs between investment alternatives across different modes of 
transportation. As a result, they may choose to finance projects that 
do not produce the highest estimated social benefits to society. By 
definition, projects that produce the highest estimated social benefits 
further the efficient use of scarce resources for transportation 
infrastructure.[Footnote 12] For example, due to the stove-piped 
funding, decision makers may decide to fund a smaller mass transit 
project instead of a high-occupancy toll (HOT)[Footnote 13] lane 
network project, which could require additional funding designated for 
other programs. The HOT lane network project, despite its potentially 
higher cost than the smaller transit project, could create a more 
efficient use of the road by allowing single drivers to pay to use the 
existing car pooling lanes and therefore provide greater overall public 
benefits. In addition, the toll revenue collected from the paying 
drivers can be used to subsidize the riders of existing transit lines 
and, therefore, potentially increasing ridership and further reducing 
congestion.[Footnote 14] 

* Economic analysis does not drive decisions. Decisions about what 
projects to fund are seldom subjected to rigorous economic analysis. 
Our prior work found that economic analysis, such as benefits and costs 
analysis, is not systematically used in the decision-making 
process.[Footnote 15] Many tools and methods to perform economic 
analysis are available, and these tools have the potential to provide 
decision makers with valuable information such as potential social, 
environmental, and safety effects of alternative transportation 
projects. For example, benefit and cost analyses integrate and monetize 
the quantifiable benefits and costs of each alternative, thereby 
allowing decision makers to more easily compare different investment 
alternatives. In most instances, however, such analyses are not 
performed and, if they are, they are often just one factor--and not 
necessarily the most important one--that decision makers consider. The 
limited extent to which formal economic analysis is systematically used 
makes it difficult for decision makers to assure they are funding 
projects that best ensure the efficient use of scarce resources. 

Various Techniques Have Been Developed to Make the Current 
Infrastructure More Efficient: 

Our review of transportation literature and our discussions with 
transportation officials identified two main categories of congestion 
mitigation techniques that are currently being used to make the current 
infrastructure more efficient. The first category includes techniques 
that enhance existing road capacity through better operations and 
transportation technology. These types of congestion mitigation 
techniques range from incident response vehicles that more quickly 
restore traffic flow after accidents to the deployment of 
transportation technology, such as metering traffic onto freeways and 
optimizing the timing of traffic signals that can improve traffic 
flow.[Footnote 16] For example, Washington State, recognizing that 
vehicle crashes can significantly reduce the capacity of freeways, 
implemented an incident response program consisting of camera 
surveillance, private tow companies, and roving patrol vehicles to 
enable a rapid response to incidents. To help clear incidents even 
faster, Washington State has a "steer it, clear it" law that requires 
drivers to move their vehicles off a main freeway if it is possible to 
do so. Another example of enhancing capacity through operations is 
utilizing access management, which is a set of techniques designed to 
control and limit vehicle access to highways, major arterials, and 
other roadways. For instance, transportation agencies have implemented 
access management techniques to improve traffic flow and reduce delays 
by increasing spacing between interchanges and redesigning 
intersections. 

The second category of congestion mitigation techniques involves 
reducing congestion by influencing driver behavior on when and where to 
drive. These techniques range from employer transit subsidies and 
flexible work schedule programs to congestion pricing. By providing 
transit subsidies or flexible work schedules, employers make it easier 
for drivers to drive during less congested times or not drive to work 
at all. Congestion pricing also attempts to influence driver behavior 
by charging drivers higher prices during peak hours. As of today, a 
major example of states implementing road pricing techniques on 
highways in the United States is the converting of high-occupancy 
vehicles (HOV) lanes to HOT lanes, which are priced lanes that offer 
drivers of vehicles that do not meet the occupancy requirements the 
option of paying a toll to use lanes that are otherwise restricted to 
HOV vehicles.[Footnote 17] Another form of congestion pricing is called 
cordon pricing, which charges a fee for any vehicle that enters a 
congested area, such as a city center. Although this type of congestion 
pricing has only been implemented in foreign countries to date, cities 
in the United States such as New York and San Francisco are studying 
the potential implementation of cordon pricing. 

These various techniques can often be used in tandem to produce a more 
robust congestion mitigation strategy. Figure 4 depicts a cross section 
of eight different techniques that both enhance existing capacity and 
influence driver behavior and demand. The strategies shown range from 
signal timing and extensive use of HOV and HOT lanes to workplace 
efforts designed to reduce traffic or shift it to less congested times 
of the day. For a more detailed list of congestion mitigation 
techniques see appendix II. 

Figure 4: Select Congestion Management Techniques that Enhance Capacity 
and Influence Driver Behavior and Demand: 

[See PDF for image] 

Source: GAO. 

[End of figure] 

Although studies and evaluations of specific projects that have 
implemented congestion mitigation techniques vary in quality and scope, 
transportation research has generally shown that such techniques have 
the potential to help reduce congestion and make better use of existing 
transportation infrastructure capacity.[Footnote 18] Specifically, some 
examples of studies and evaluations suggest that techniques such as 
incident response programs, signal timing coordination, and HOT lanes 
help maximize existing capacity by providing improved traffic flows, 
reduced delays, and increased vehicle speeds. Following are examples: 

* In Washington State, transportation officials have monitored the 
results of their incident response program and found that the average 
time to clear incidents has decreased from 33 minutes to 16 minutes, 
which in turn reduced the amount of time that the incident was creating 
congestion by about half. 

* A study of a traffic signal optimization project in the Denver area 
showed that the project resulted in a 13 percent reduction in vehicle 
travel times and a 17 percent improvement in travel speed. 

* An evaluation of the Express (HOT) lanes for the State Route 91 
project in Orange County, California, showed that although the HOT 
lanes represent only 33 percent of the capacity of State Route 91, they 
carry an average of 40 percent of the traffic during peak travel times 
(see fig. 5). 

Figure 5: Express Lanes and General Purpose Lanes on State Route 91 in 
Orange County, California: 

[See PDF for image] 

Source: Caltrans. 

[End of figure] 

In our review of transportation research and discussions with 
transportation officials, we found that congestion mitigation 
techniques are most effective when tailored to the particular 
situation. For example, because they encourage some additional traffic 
from single-occupancy vehicles, HOT lanes have generally been used in 
cities with congested freeways and underutilized HOV lanes. Similarly, 
because it discourages vehicles from entering a central urban zone, 
cordon pricing is used in large cities with developed transit systems 
that provide alternative modes of travel to the city centers. In 
addition, congestion mitigation techniques have been found to be more 
effective when used in combination. For example, the following 
techniques have been effective: 

* When a major accident occurs on a freeway, message signs with traffic 
information can be used to divert traffic to a parallel arterial, while 
incident response vehicles work to clear the freeway. 

* With the installation of ramp meters, lines of queuing vehicles 
sometimes can back up onto local arterials. To help address this 
problem, other techniques, such as optimizing signal timing, can be 
used to reduce the rate at which vehicles enter the freeway ramp. 

* Electronic toll collection technology can be used to collect tolls 
from HOT lane vehicles. This significantly reduces the delays caused by 
vehicles stopping to pay at toll booths. 

Transportation Decision Makers Are Using Similar Approaches for 
Implementing Congestion Mitigation Techniques, but Challenges Exist: 

At locations we reviewed, officials chose varying congestion mitigation 
techniques but tended to implement them with a similar three-pronged 
approach: (1) changing planning and related processes to give them 
higher priority, (2) developing creative mechanisms to fund them, and 
(3) collaborating with multiple stakeholders to put them in place. 
However, officials told us that many of the congestion mitigation 
techniques they used had been able to provide benefits only at the 
margins because several persistent issues prevented them from using 
these congestion mitigation techniques more fully. These issues ranged 
from resolving jurisdictional authority to identifying sources that 
would provide sufficient funding for larger-scale projects. 

Officials Report Giving Congestion Mitigation Techniques More Priority 
in Their Transportation Planning: 

State and local transportation officials we interviewed told us that 
they are changing their transportation planning priorities to reflect a 
greater emphasis on congestion mitigation techniques. To make these 
congestion mitigation techniques a priority, officials have established 
new goals and priorities, modified their project selection process, 
restructured their organizations, and adopted new policies and 
initiatives. 

Setting Goals That Incorporate Congestion Mitigation: 

Officials from the transportation agencies we visited reported 
establishing goals related to using the existing road infrastructure 
more efficiently by implementing congestion mitigation techniques. They 
generally said they had incorporated these goals into both their long- 
range and short-range transportation plans.[Footnote 19] Table 1 shows 
examples of these goals identified in their plans. Our review of these 
plans showed that the new goals reflect a shift in emphasis--that is, a 
movement from the traditional approach that has been and, in many cases 
still is focused on the construction of new road capacity or the 
maintenance of existing road infrastructure, to a greater emphasis on 
managing the system more efficiently. 

Table 1: Examples of Long-range and Short-range Transportation Plans at 
Locations GAO Visited: 

Location: San Diego, CA; 
Added emphasis on managing existing infrastructure more efficiently: 
Long-range plan (through 2030) now includes a focus on making the best 
use of the existing transportation system and a shift in emphasis from 
expanding the system to managing demand. The plan highlights such 
techniques as improving traffic information provided to drivers, 
continuing the current incident management program, developing new HOT 
lanes, improving transit and telework programs, and continuing their 
van pool and car pool programs. 

Location: Orlando, FL; 
Added emphasis on managing existing infrastructure more efficiently: 
Long-range plans include a goal of better managing and operating the 
system, specifically prioritizing incident management programs, and 
linking land-use strategies with the transportation plan. 

Location: Seattle, WA; 
Added emphasis on managing existing infrastructure more efficiently: 
The City of Seattle's Comprehensive Plan (the 20-year policy plan) 
recognizes that expanding streets and roads to accommodate cars is 
generally unproductive. In addition, opportunities to widen or 
construct new streets in Seattle are extremely limited because of its 
built-out, urban environment. The plan suggests increasing the use of 
transit, walking, bicycling, carpooling, and other alternatives, such 
as addressing parking in the city. 

Location: Denver, CO; 
Added emphasis on managing existing infrastructure more efficiently: 
Short-range transportation plan now includes funding for intelligent 
transportation systems and demand management programs, such as 
improving ramp metering for entering highways, improving signal timing 
on roads, and expanding outreach to employers to promote telework and 
flextime work. 

Location: Bellevue, WA; 
Added emphasis on managing existing infrastructure more efficiently: 
Long-range planning program routinely includes projects that examine 
how land-use decisions influence system performance and their short-
range transportation plan includes using operations methods, such as 
real time traffic flow and ITS applications to optimize traffic flow. 

Source: GAO. 

[End of table] 

Modifying Project Selection Process to Emphasize Congestion Mitigation 
Goals: 

Some transportation agencies we visited modified their transportation 
project selection process to provide greater emphasis to projects that 
use congestion mitigation techniques. For example, in considering which 
projects to select for funding, the metropolitan planning organization 
for the Denver region now awards points to projects that use certain 
congestion mitigation techniques, such as installing left-turn lanes, 
promoting car pools, coordinating traffic lights, or managing 
incidents. Officials said they hope awarding points will provide 
incentives for local planners to include such congestion mitigation 
techniques in their projects. Several other metropolitan planning 
organizations we interviewed, such as Virginia's Hampton Roads Planning 
District Commission, had modified their project selection process to 
promote projects that have a regional objective, which prior to these 
changes, would have had a low probability of funding under the previous 
allocation program. Officials said that by modifying the selection 
process, they can better align which projects are selected to their 
overall goal of using the existing infrastructure more efficiently. 

Restructuring Organizations to Align with Transportation Planning 
Goals: 

To ensure that their organizations are aligned with transportation 
goals, transportation agencies in a number of locations we visited had 
restructured their organizations by creating new departments or 
committees. For example, Seattle's metropolitan planning organization, 
the Puget Sound Regional Council, created a new team dedicated to 
working on projects that improve the operations of the transportation 
system. This department was designed to work with other transportation 
agencies to improve mobility through implementing demand management, 
improving operational efficiency, and identifying capacity solutions at 
the corridor and regional planning levels. Orlando's metropolitan 
planning organization created a management and operations department 
and a subcommittee composed of local planners and traffic engineers, 
which is responsible for sustaining and increasing funding for projects 
that use congestion mitigation techniques, such as incident management, 
and strategies to manage driver behavior. 

Adopting Policies or Regulations That Promote Congestion Mitigation 
Techniques: 

At some locations we visited, greater use of congestion mitigation 
techniques was also spurred by state policies. We found the following 
examples: 

* In 1991, Washington State's legislature passed a law designed to 
reduce traffic congestion, reduce air pollution, and petroleum 
consumption by requiring metropolitan planning organizations to foster 
employer-based programs that decrease the number of commuting trips 
made by people driving alone. Since the law was passed, the number of 
vehicle trips has dropped statewide. In the central Puget Sound region, 
where Seattle is located, the number of vehicle trips made during the 
morning commuter hours has dropped by 14,000, reducing peak travel 
delay by an estimated 11.6 percent, on average, each weekday morning in 
the region. 

* California requires all urbanized areas to monitor the performance of 
the transportation system, develop programs to address short-term and 
long-term congestion, and better integrate transportation and land-use 
planning through congestion mitigation programs. In response, San 
Diego's metropolitan planning organization, the San Diego Association 
of Governments, developed a congestion mitigation program that 
encourages the use of strategies other than road widening or extensions 
to address congestion at low costs, such as encouraging transit use, 
establishing programs for car pools, and teleworking programs. 

* Oregon through its Interchange Area Management Plan rules has 
introduced new requirements that stipulate local governments jointly 
manage access on crossroads in the vicinity of interchanges. 
Specifically, regulations require that new intersections at crossroads 
be placed at least 1,320 feet from the interchange ramp terminals, 
thereby reducing the potential backups on the highway exit ramps. 

Agencies Report Developing New Methods to Fund the Use of Congestion 
Mitigation Techniques: 

Transportation officials told us that the mode-specific, or stove-piped 
funding structure for transportation projects, together with a general 
lack of resources for transportation projects, constrains their ability 
to invest in congestion mitigation techniques. As a result, they said, 
they often have to find alternative methods to supplement traditional 
funding sources. The methods they cited included imposing additional 
tolls, local taxes, or development impact fees; developing partnerships 
with private industry; and designating separate funding. 

Imposing Tolls, Local Taxes, or Development Impact Fees: 

A number of state and local governments in the locations we visited had 
imposed additional tolls, local taxes, and development impact fees to 
provide funding for the implementation of congestion mitigation 
techniques. Officials said they had done so because traditional funding 
sources were not generating sufficient resources. Many of these revenue 
sources were focused in a specific region and were geared toward 
implementing specific congestion mitigation techniques. For example, 
voters in the San Francisco region passed an increase in toll fees on 
the region's seven state-owned bridges to support the Regional Traffic 
Relief Plan, which funds such projects as expanding transit options, as 
well as improving transit connections and several freeway bottlenecks. 
Several other regions passed sales, property, or gasoline taxes. For 
example, San Diego passed a half-cent sales tax to implement a number 
of congestion mitigation techniques to help improve traffic congestion 
on the most highly congested corridors in the region. This included 
funding for new HOV and managed lanes along highways, new connectors to 
the highways, and transit improvements. 

Some localities generated additional transportation funding through 
another source--development impact fees.[Footnote 20] They used this 
approach particularly when new development had a significant effect on 
the current road network. Florida, for example, has passed a law that 
regulates large-scale developments that have substantial impacts on the 
transportation system. This program allows local governments to assess 
new developments and assign fees related to their impact on the local 
infrastructure, including transportation. Between 1993 and 2004, this 
program provided local governments with $2 billion statewide for 
efforts to improve transportation infrastructure, including ways to 
reduce congestion. 

Developing Partnerships with Private Industry: 

Transportation agencies reported developing partnerships with private 
industry to help fund congestion mitigation techniques. According to 
transportation experts, working with private companies can offer a 
number of benefits for the transportation agency, such as expediting 
the project schedule, reducing costs, and providing access to private 
funding sources. Examples we identified included the following: 

* In 1995, California's Department of Transportation partnered with a 
private company to develop a four-lane, 10-mile toll road of HOT lanes 
in the median of a freeway (State Route 91) in Orange and Riverside 
Counties. The company financed, managed, and collected revenues from 
the variable-priced tolls on the HOT lanes. In 2003, Orange County 
Transportation Authority purchased the HOT lanes and is now managing 
them. 

* In Virginia, a private company is installing equipment to collect 
traffic data on all of the state's highways and some major arterial 
roads, which could be used for local intelligent transportation systems 
and for transportation planning. The company will have permission to 
sell the information to private companies and individual drivers but 
will also allow the local jurisdictions to obtain and use the data for 
free. 

* State Farm Insurance entered a partnership with the Florida Turnpike 
to provide funding for the State Farm Safety Patrol--a 24-hour roadway 
assistance and service program that provides free driver assistance to 
motorists along Florida's Turnpike. State Farm provides funding 
annually to the Florida Turnpike and, in exchange, places 
advertisements on the State Farm Safety Patrol vehicles. These vehicles 
help improve mobility by minimizing the duration of incidents, 
assisting disabled drivers, and removing road debris--all of which can 
help reduce vehicle crashes. (See fig. 6.) 

Figure 6: Florida Road Ranger Incident Response Vehicle: 

[See PDF for image] 

Source: Florida DOT. 

[End of figure] 

Designating Specific Funding within Existing Resources: 

Some transportation agencies we visited have designated a certain 
amount of funding out of their traditional transportation funding for 
congestion mitigation techniques. Officials at these agencies said 
doing so ensures that congestion mitigation projects receive some 
funding. For example, each year from 2007 to 2011, Denver's 
metropolitan planning organization plans to designate $20 million to 
$23 million of its state and federal funding for congestion mitigation 
techniques such as van and car pool programs and traffic signal 
improvements. Similarly, the Orlando metropolitan planning organization 
has designated $2 million annually of its state and federal funds for 
its intelligent traffic system program. Orlando officials said that 
they have decided to increase this funding to $4 million annually in 
the future because of the potential for improving efficiency. 

Transportation Agencies Are Collaborating with Multiple Stakeholders: 

Transportation agencies we visited reported working with multiple 
partners to implement congestion mitigation techniques. According to 
officials, the success of these techniques depends on such 
coordination. For example, in Washington State, the Department of 
Transportation and the state patrol established standard operating 
procedures for such matters as data sharing, traffic management, and 
incident response. In several other states we visited, transportation 
agencies have established a goal of clearing a highway accident within 
90 minutes of when the first responder arrives. Coordinating signal 
timing across jurisdictions was another technique for which 
transportation officials said collaboration was important. 

We found a number of examples where transportation agencies participate 
in multijurisdictional groups to help ensure that transportation plans 
encompass regional and comprehensive perspectives. For example, the 
Central Florida Metropolitan Planning Organization Alliance was created 
to coordinate regional transportation planning. This council consists 
of six metropolitan planning organizations that include ten counties in 
Central Florida, and its membership includes metropolitan planning 
organizations' board members and staff, and state transportation staff. 
Similarly, several metropolitan planning organizations that we visited 
have committees focused on regional planning. Participants on these 
committees include representatives from regional jurisdictions and 
transit agencies. 

Persistent Issues Keep Congestion Mitigation Techniques from Having 
Greater Effect: 

While officials at the locations we visited were making greater use of 
these congestion mitigation techniques, they also said a number of 
issues prevented them from implementing these techniques to the extent 
desired. As a result, they said, that congestion mitigation techniques 
they were implementing could provide only marginal improvement to the 
efficiency of the road network. Issues they cited included the 
following: 

* Lack of authority. Officials of local government agencies said some 
congestion mitigation techniques need to be implemented by federal or 
state agencies and cannot be legally implemented by local 
transportation agencies. For example, while cities implement congestion 
mitigation techniques like intelligent transportation systems, they 
generally cannot implement large-scale techniques such as congestion 
pricing on major state highways. Being able to integrate congestion 
mitigation techniques comprehensively, they said, may be critical for 
seeing improvements on the road network. 

* Barriers to obtaining additional funding. Finding alternative funding 
for projects can be difficult, officials said. Efforts to impose new 
charges, such as toll fees on roads, may be opposed by the public, 
since the public can feel as though it is being charged twice for use 
of the roads. In some states, funding sources such as development 
impact fees are not authorized by law, and those that are authorized by 
law have a number of provisions on how local governments can use 
revenues that may affect their ability to use these fees to their 
fullest. 

* Lack of complete and reliable data. The lack of complete and reliable 
data hinders the ability of transportation officials to make fully 
informed decisions about implementing congestion mitigation techniques. 
For example, data about traffic flow throughout the day, rather than at 
a single time, are crucial to produce valid representations of travel 
needs and problems. However, reliable and complete data are not always 
available--which can result in forecasting errors or limit the ability 
to conduct outcome evaluations.[Footnote 21] 

* Difficulties in resolving jurisdictional issues. Many transportation 
officials we interviewed noted the struggle to align different 
perspectives when trying to work regionally on projects. Often, they 
said, there are competing ideas of which jurisdictions should be 
responsible for the management and funding of projects that cross 
boundaries. 

* Limitations of the current funding and decision-making process. 
Transportation officials noted that the current funding and decision- 
making processes, with their orientation to particular modes of 
transportation and their limited reliance on analysis of the costs and 
benefits of various transportation alternatives, provide a built-in 
preference for projects that build or maintain transportation 
infrastructure rather than try to use existing structure more 
efficiently. Although congestion mitigation techniques may produce the 
highest estimated social benefit, in times of constrained budgets, many 
officials said that obtaining money for congestion mitigation projects 
can be difficult. 

Various Strategies Exist for Increasing the Efficient Use of 
Infrastructure: 

Various strategies exist for increasing the efficient use of 
infrastructure, according to the officials and experts we talked with 
and the studies we reviewed.[Footnote 22] These strategies include 
applying congestion mitigation techniques on a regional basis and 
linking federal-aid highway funding to performance. We grouped these 
strategies by the level of government best suited to consider and 
implement them, given their current authorities, roles, and 
responsibilities (see fig. 7). In some cases, all levels of government 
would need to be involved in implementing the strategy; in other cases, 
the federal government or a state or local government would be most 
appropriate to implement the strategy. These strategies are not 
mutually exclusive and ideally would be implemented in a comprehensive 
manner, according to transportation research and transportation 
officials and experts we interviewed. 

Figure 7: Strategies for Making More Efficient Use of Existing 
Infrastructure: 

[See PDF for image] 

Source: GAO. 

[End of figure] 

Three Strategies Crosscut All Levels of Governments: 

We identified three strategies that would likely require the attention 
and involvement of all levels of the government to be successfully 
implemented. These strategies are (1) considering how the private 
sector can be used in managing existing road infrastructure, (2) 
determining the feasibility of expanding use of the user-pay concept 
for managing demand and generating revenue for transportation 
investments, and (3) developing a systematic performance-based 
management approach to increase the accountability of public 
expenditures and to link performance to investment decisions. 

Consider How the Private Sector Can Be Used in Managing Existing 
Infrastructure: 

Public policymakers at the federal, state, and local levels could 
consider how the private sector can be used in the operation and 
management of the existing road infrastructure. Proponents believe that 
expanding the use of public-private partnerships could take advantage 
of the private sector's ability to manage assets with the intended 
outcome of providing a more efficiently operated road network. Private 
companies, driven by the need to make a return on investment, are 
incentivized to manage assets and provide services in efficient ways. 
Specifically, how efficiently they operate an asset directly affects 
the profits they derive from their investments and is directly linked 
to the overall success of the company. If a partnership is designed and 
structured appropriately, transportation agencies could leverage this 
incentive. To date, public-private partnerships in the United States 
have often been used to manage toll roads, such as State Route 91, as 
described earlier. In addition, a recently emerging public-private 
partnership model is where the private sector is awarded, through a 
long-term lease agreement, the concession to operate, maintain, and 
collect tolls on existing publicly owned highways. In return for the 
revenues collected by the tolls, these concessions often require that 
the private companies meet established performance standards, which can 
include maintaining the condition of the road to a specific standard, 
and allow increasing toll rates on an annual basis in line with 
inflation.[Footnote 23] 

The federal government and some state governments have also shown 
interest in developing public-private partnerships to support research 
and development of advanced technology that can help enhance the 
capacity of the existing road infrastructure. Transportation experts 
argue that advanced technology could potentially allow for more 
efficient use of the road network by improving safety and increasing 
the availability of transportation data to drivers and transportation 
planners. An example of governments partnering with private industry in 
supporting research and development of advanced technology is the 
Vehicle Infrastructure Integration (VII) program. The VII program uses 
technology installed in the road infrastructure and the individual 
vehicle to establish vehicle-to-vehicle and vehicle-to-roadside 
communications (see fig. 8). This system would use vehicles as 
collectors of real time traffic information and more complete data from 
highways and arterial roads, which would be processed and distributed 
to drivers, transportation planners, and traffic managers. In 2004, the 
federal government, the American Association of State Highway and 
Transportation Officials, 10 state departments of transportation, and 
several vehicle manufacturers[Footnote 24] formed an informal VII 
working group to examine the feasibility of widespread deployment and 
to establish an implementation strategy. The VII coalition, which is 
made up of the VII working group and the executive leadership team, 
will report its initial findings in 2008. 

Figure 8: Representation of the VII Mobility Applications: 

[See PDF for image] 

Sources: GAO and DOT. 

Note: The VII information flow differs from the above graphic for many 
safety applications, where the data is sent to oncoming vehicles 
instead of the aggregator, and there is an interface to local signal 
control systems. 

[End of figure] 

Expand the Use of the User-Pay Concept: 

The user-pay concept--that is, users should help pay for the 
infrastructure they use--is a long-standing aspect of transportation 
policy in the United States. For instance, federal, state, and local 
governments have imposed excise taxes on motor fuels and other taxes on 
inputs into driving, such as taxes on tires or fees from registering 
vehicles or obtaining operating licenses. These taxes, in turn, are 
used to pay for highway projects. Similarly, some state and local 
governments charge tolls on certain roads. These tolls can generate 
revenues that are consistent with the user-pay principle because the 
driver is directly paying to use that specific road and the revenues 
collected from the toll go directly to pay for its construction, 
maintenance, and operation.[Footnote 25] 

The federal government and some state and local governments are 
studying new alternatives that expand the user-pay concept. At the 
federal level, Congress authorized a road user fees study,[Footnote 26] 
which is to examine an option to assess highway user fees based on 
actual mileage driven. The final report is scheduled to be submitted to 
Congress in July 2009. At the state level, Oregon's Department of 
Transportation tested a pilot program that collects a mileage-based fee 
in lieu of the state gas tax. The program used on-vehicle mileage 
counting devices that record the number of miles driven and download 
mileage information at two gas stations that were equipped with mileage 
readers on the fuel pumps. Drivers are then charged a per-mile fee 
instead of the gas tax. The pilot program ended in March 2007, with a 
final study expected in September 2007.[Footnote 27] 

Measure Results and Manage the Existing Infrastructure with Them in 
Mind: 

A performance-based management approach can increase accountability and 
performance of the existing infrastructure. As we have previously 
reported,[Footnote 28] a performance-based management approach for 
transportation would include establishing performance targets, 
developing performance measures, and enhancing data quality.[Footnote 
29] An important element of a performance-based approach is evaluating 
the results of projects or conducting outcome evaluations. Such 
evaluations allow the public to hold the government accountable for 
results. Outcome evaluations also offer transportation agencies the 
opportunity to learn from the successes and shortcomings of past 
projects to better inform future planning and decision making. Further, 
such evaluations help to provide better analytic information to 
decision makers. For example, information from outcome evaluations 
could help inform decisions, such as determining whether a community 
would generate higher benefits from investing in a ramp metering system 
on a highway or adding a new lane instead, or whether investing in 
transit provides higher benefits and lower costs compared with building 
a new road. However, outcome evaluations are not required for highway 
projects as a condition of federal funding and are not typically 
performed. In contrast, SAFETEA-LU requires before and after studies as 
a condition of receiving New Starts funds for completed transit 
projects.[Footnote 30] 

For transportation agencies to be able to use a performance-based 
management approach, transportation experts highlighted the importance 
of being able to collect comprehensive and robust traffic data. 
However, the ability of transportation agencies to collect traffic data 
is limited for two major reasons. First, the majority of our nation's 
highways and arterials do not have the data collection infrastructure 
to be able to provide continued and comprehensive data. This lack of 
coverage can leave significant data gaps in a local road network. 
Second, even when state and local governments have built data 
collection infrastructure, providing funding for its maintenance is 
difficult and, therefore, this infrastructure can fall into disrepair 
and not provide the data. While the development of a performance-based 
management approach should not be totally dependent on the readily 
available data, transportation research does state that agencies should 
try to optimize the use of existing or accessible data in their 
performance management system. 

Several Strategies Relate Mainly to State and Local Governments: 

Although some strategies cut across all levels of government, other 
options are more appropriately considered by state and local 
governments, given their current roles and responsibilities. We 
identified four strategies that state and local transportation 
agencies, with their primary responsibility for building, maintaining, 
and operating the road infrastructure, could consider in their efforts 
to increase the efficient use of existing infrastructure. These options 
are (1) implementing a combination of supply-related and demand-related 
congestion mitigation techniques, (2) applying congestion mitigation 
techniques on a regional basis, (3) fully integrating transportation 
and land-use planning, and (4) providing leadership to build support 
for implementing comprehensive congestion mitigation techniques. 

Implement a Combination of Supply-Related and Demand-Related 
Techniques: 

Research on various congestion mitigation techniques indicates that 
efficient use of the existing road infrastructure is best accomplished 
through an approach that uses a combination of supply-related and 
demand-related techniques. Supply-related congestion mitigation 
techniques include enhancing the capacity and operation of the road 
supply by, for example, using intelligent traffic system and work zone 
management techniques. Demand-related congestion mitigation techniques, 
such as road pricing and a vanpool program, could improve the flow and 
performance of roads by reducing the number of drivers using existing 
roads during peak demand times. Although these congestion mitigation 
techniques can provide benefits when implemented individually, using 
them in a comprehensive manner will provide the greatest benefits, 
according to research. For example, implementing supply-related 
features of intelligent traffic systems can enhance the effectiveness 
of demand-related techniques like commuting on a flexible schedule by 
providing real-time traffic information to drivers so that they can 
adjust their departure times to avoid heavy congestion. 

To demonstrate the benefits of using a comprehensive approach for 
reducing congestion, DOT has initiated the Urban Partnership Agreement. 
This program will provide financial resources, including some 
combination of grants, loans, and borrowing authority, to 
transportation agencies that implement congestion reduction initiatives 
that combine tolling, transit, telecommuting, and technology as part of 
a systemwide, comprehensive strategy. In addition to the financial 
assistance, DOT will also provide regulatory flexibility and dedicate 
expertise and personnel to help transportation agencies implement 
congestion mitigation techniques. DOT announced the selection of nine 
cities as preliminary partners and is planning to announce the 
selection of between one-five final partners by August 8, 2007. 

Apply Congestion Mitigation Techniques on a Regional Basis: 

Since road networks often cross multiple jurisdictions, state and local 
governments need to apply congestion mitigation techniques on a 
regional basis, according to transportation research. By working 
together, jurisdictions can ensure that their efforts to manage 
congestion include a combination of supply-related and demand-related 
congestion mitigation techniques. For example, traffic signal timing is 
one technique that can provide significant benefits to drivers by 
providing for the smooth flow of traffic along streets and highways. To 
fully enhance mobility, however, jurisdictions need to coordinate the 
timing along an entire corridor. A 2005 report by the National 
Transportation Operations Coalition found that a majority--56 percent-
-of jurisdictions did not report strong efforts in coordinating traffic 
signal timing across jurisdictions.[Footnote 31] 

Because of the importance of implementing these techniques on a 
regional basis, especially when there are major road corridors 
involved, a growing number of transportation agencies have implemented 
corridor management plans. Corridor management plans can take many 
forms and can be implemented in a number of ways. A recent 
Transportation Research Board study[Footnote 32] reported that 
transportation agencies have used a variety of different instruments to 
implement these corridor management plans, such as memorandums of 
understandings and intergovernmental agreements. For example, the Iowa 
Department of Transportation entered into agreement with three local 
jurisdictions to implement an access management plan, which established 
access management standards on U.S. Highway 6, which runs east to west 
through Des Moines. This type of coordination has also been supported 
by DOT, through its Integrated Corridor Management Initiative. This 
initiative will provide federal funding to an agency or organization 
that demonstrates support of the overall concept of corridor 
management, which could consist of multiple jurisdictions. 

Integrate Transportation Planning More Fully with Land-Use Planning: 

Many transportation officials we spoke with stated that transportation 
planning by state and local government must be more fully integrated 
with land-use planning, such as zoning policies or growth management 
policies. There is a high level of interconnection between land use and 
transportation. For example, the traffic generated from a new major 
shopping center may overwhelm existing transportation infrastructure. 
However, in most areas, land use and transportation decisions are made 
by separate agencies or jurisdictions, with each having significant 
impact on the other's investment decisions. In cases where there is 
insufficient coordination between land use and transportation planners, 
transportation agencies may be required to make unanticipated 
expenditures for transportation infrastructure. 

During a Transportation Research Board-sponsored peer exchange on 
linking transportation and land use, transportation officials 
identified a number of efforts that are currently being used to better 
integrate transportation and land-use decisions. State transportation 
officials indicated that they have identified several new areas of 
activity that incorporate the concepts of smart growth and 
transportation planning.[Footnote 33] For example, the Pennsylvania 
Department of Transportation's Transportation Project and Land Use 
Coordination Initiative provides federal transportation planning funds 
to local communities for studies and coordinated activities linking 
land-use planning and transportation. 

Building Support for Congestion Mitigation Techniques: 

Our past work[Footnote 34] has found that strong leadership is needed 
to help build support for implementing congestion mitigation techniques 
on a comprehensive basis. There are some techniques, such as the use of 
congestion pricing, which must sometimes overcome political and public 
opposition. Strong leadership can communicate the essential ideas and 
values of a project and, therefore, highlight the benefits that these 
techniques can provide for drivers. For example, in Minnesota, a task 
force of state and local officials, citizens, and business leaders was 
convened in 2001 to explore a range of road pricing options, including 
the conversion of HOV lanes to HOT lanes, and make recommendations to 
elected officials. Since tolling had been fairly controversial in the 
past, the task force was seen as a way to provide a more credible and 
independent review. Ultimately, with the task force's and Governor's 
support, legislation passed that converted HOV to HOT lanes on a major 
highway. Figure 9 provides a brief description of Minnesota's 
experience with HOT lanes. 

Figure 9: Minnesota's "MnPass" Program: 

Minnesota opened the MnPass Express Lanes in May 2005. The MnPass 
provides single-occupancy drivers the opportunity to pay a toll to use 
the HOV lanes on Interstate 394, which carries traffic to and from 
downtown Minneapolis and western suburbs. The results of the HOT lanes 
have been significant. A recent survey concluded that support for 
allowing single passenger vehicles to use the HOV lane for a fee 
remained high, with 65 percent of respondents indicating this was a 
"good idea," 1 year after the HOT lane was implemented. In addition, 
this survey showed that 93 percent of users were satisfied with the 
electronic tolling used by MnPass, 88 percent were satisfied with the 
traffic speed in the HOT lanes, and 72 percent were satisfied with the 
safety of merging between the HOT lanes and general purpose lanes. The 
results are based on a survey of 1,228 residents aged 18 years and 
older living within the study area in Minnesota. 

Source: NuStats, MnPass Evaluation Attitudinal Panel Survey Wave 3 
(Austin, TX.: August 2006). 

[End of figure] 

Several Strategies Relate Mainly to the Federal Government to Consider: 

The federal government provides funding to state and local governments 
for road and transit infrastructure, establishes legislation and 
regulations that influence the performance and safety of the system, 
and administers transportation programs that cover a range of areas. 
Given these roles and responsibilities, there are several strategies 
that the federal government could consider to help promote the 
efficient use of infrastructure, including (1) linking funding more 
directly to performance, (2) increasing the flexibility provided to 
state and local government to promote innovate solutions, and (3) 
focusing on projects (or transportation corridors) of national 
interest. 

Link Federal-Aid Highway Funding to Performance: 

The federal government could link funding to state and local efforts to 
improve the efficiency and performance of the existing road 
infrastructure. We have previously reported that the federal-aid 
highway funding is currently not linked to performance.[Footnote 35] As 
a result, the federal government misses an opportunity to use financial 
incentives to improve performance and to hold agencies accountable for 
results. The federal government could use incentives that link funding 
to particular outcomes, such as implementing congestion mitigation 
techniques to encourage state and local governments to use existing 
infrastructure more efficiently. Incentives could also be used to 
increase state, regional, and local agencies' utilization of analytical 
information and tools to ensure that decision makers are making 
investment decisions that fully examine all alternatives, including 
congestion mitigation techniques. 

Increase Flexibility to State and Local Decision Makers: 

The federal government could provide additional flexibility to state 
and local governments for implementing innovative solutions to reduce 
congestion and enhance mobility, according to transportation experts. 
This flexibility could take many forms. First, the federal government 
could build on trends giving states greater flexibilities and 
discretion with their federal-aid highway program funds.[Footnote 36] 
Increasing flexibility and discretion would recognize the changing 
nature of FHWA's role and the federal-aid highway program, which has 
been functioning, to some extent, as a revenue sharing, general purpose 
grant program. Devolving funding responsibilities to the states in a 
manner consistent with that function would build on the flexibilities 
already present and would not require abandoning the program's 
regulatory component. For example, states and localities could use 
federal-aid highway funding to implement travel demand management 
techniques such as increasing the number of vanpools. 

The federal government could also continue to liberalize some of the 
long-standing federal restrictions on states and local governments' use 
of congestion mitigation techniques, such as road pricing techniques. 
By removing these restrictions, the federal government would allow 
state and local governments to expand the use of certain user-pay 
options. For example, because states have recognized that many HOV 
lanes have been underused and, therefore, have excess capacity, HOT 
lanes are becoming more widely accepted by state and local governments 
as a way to maximize existing road capacity by managing demand and 
offering drivers additional choices. SAFETEA-LU enhanced and clarified 
provisions on the states' ability to build or convert existing HOV 
lanes on interstate highways into HOT lanes, as long as states monitor 
and assess the operation of the lanes to ensure the lanes do not become 
degraded.[Footnote 37] However, there are still restrictions on the 
states' ability to implement road pricing techniques on general purpose 
lanes. For example, SAFETEA-LU includes an explicit restriction on the 
use of road pricing techniques on Interstate 4 in Orange County, 
Florida. 

Placing Additional Focus on Projects That Provide National Public 
Benefits: 

The federal government could refocus its role and become more active in 
the management of the surface transportation infrastructure on projects 
that are within the national interest. In our prior work,[Footnote 38] 
we have stated that government investment in transportation projects, 
such as freight improvement projects or intermodal projects at 
airports, may be warranted if there is the potential of producing 
benefits to the public and if these projects are unattractive to the 
private sector. Public benefits could include reducing the external 
costs of transportation, such as reducing fuel emissions and roadway 
congestion. Considering whether the project has the potential to reduce 
the external cost of transportation provides an indication of a 
project's potential for yielding a good return. The federal government 
could take a more active role, beyond funding and oversight, if certain 
projects could provide public benefits. For example, in our freight 
work, we highlighted that improving freight mobility through the 
implementation of a short sea shipping service may have the effect of 
shifting some freight from truck to water and, as a result, reduce 
external costs such as pollution and congestion. Federal options could 
range from providing public subsidies to the private sector to taking 
on a more active planning role, such as during the development of the 
interstate highway system. However, such options would involve a 
fundamental shift in federal transportation policy, and officials would 
have to implement this option carefully to ensure that this support 
would result in real economic benefits, from a national perspective, 
and not represent a transfer of economic activity from one area to 
another. 

Concluding Observations: 

The demand on our nation's road infrastructure is expected to continue 
increasing for the foreseeable future. This continued demand comes at a 
time when many of the nation's major roadways are at capacity during 
peak hours--creating increasing levels of congestion throughout the 
nation. Given today's fiscal, environmental, and land-use concerns, the 
days when our nation could build our way out of congestion have passed. 

In general, however, transportation policy is still focused on building 
or maintaining road capacity--not efficiently operating and managing 
the existing infrastructure. Many transportation experts emphasize that 
transportation policy should be refocused to allow decision-makers to 
use all the tools at their disposal to more efficiently operate and 
manage their infrastructure--including nonbuild congestion mitigation 
techniques, such as congestion pricing. Congress and DOT have 
recognized the importance and benefits of efficiently managing and 
operating the existing infrastructure. Some state and local governments 
have also adopted congestion mitigation techniques, such as HOT lanes. 
However, to date, such efforts at the state and local level have been 
confined to a limited number of locations and have not typically been a 
part of a more comprehensive strategy to operate and manage the 
existing infrastructure more efficiently. Until congestion mitigation 
techniques are used in a more comprehensive manner, the full potential 
of these techniques will not be realized. DOT's emphasis on increasing 
the efficient use of existing infrastructure in its national strategy 
to reduce congestion is an important step forward. As DOT moves forward 
with the implementation of this strategy, it will likely have the 
opportunity to explore strategies to provide incentives to state and 
local governments to consider and implement congestion mitigation 
techniques in a more comprehensive manner, including the strategies we 
identified. 

Agency Comments and Our Evaluation: 

We provided copies of this report to DOT for its review and comment. 
DOT officials provided technical clarifications, which we incorporated 
as appropriate. 

We will send copies of this report to congressional committees with 
responsibilities for surface transportation programs, DOT officials, 
including the Secretary of Transportation, and the administrator of 
FHWA. We will make copies available to others on request. In addition, 
the report will be available at no charge on the GAO web site at 
http://www.gao.gov. 

If you have any questions about this report, please contact me at 
heckerj@gao.gov or by telephone at (202) 512-2834. Contact points for 
our Offices of Congressional Relations and Public Affairs may be found 
on the last page of this report. GAO staff who made key contributions 
to this report are listed in appendix III. 

Sincerely yours, 

Signed by: 

JayEtta Z. Hecker: 
Director, Physical Infrastructure Issues: 

[End of section] 

Appendix I: Objectives, Scope, and Methodology: 

The objectives of this report were to (1) identify the factors that 
inhibit the efficient use of the existing infrastructure of roads and 
highways, (2) identify what techniques have been developed for making 
the current infrastructure more efficient and what is known about the 
results, (3) how local decision makers have implemented these 
techniques, and (4) what strategies exist for increasing the efficient 
use of existing infrastructure? 

To identify the factors that inhibit the efficient use of the existing 
infrastructure of roads and highways, we reviewed reports and studies 
issued by federal, state, and local agencies, transportation research 
organizations, and academia, as well as our past work in surface 
transportation. A GAO economist reviewed these reports and studies, 
which were identified by searching economics and transportation 
literature, and found their methodology and economic reasoning to be 
sound and sufficiently reliable for our purposes. 

To identify the techniques that have been developed to make more 
efficient use of the transportation infrastructure and what is known 
about the results of these techniques, we interviewed Department of 
Transportation's Federal Highway Administration officials and state and 
local transportation officials from our site visit locations, as well 
as representatives from various associations with experience 
implementing and/or analyzing the results of such techniques. We also 
reviewed transportation research by transportation organizations and 
studies and evaluations of individual projects conducted by federal, 
state, and local transportation agencies. 

To determine how local decision makers have implemented these 
techniques and what is known about the extent to which these approaches 
are making the current infrastructure more efficient, we conducted site 
visits or interviews of federal, state, and local transportation 
officials about urban areas in five states that have experience with 
implementing various congestion management techniques--Denver, Colo; 
Northern Virginia, Va;[Footnote 39] Orlando, Fla; San Diego, San 
Francisco-Oakland, and San Jose, Calif; and Seattle, Wash. We selected 
this nongeneralizable sample of states based on geographical diversity 
and after reviewing the Texas Transportation Institute's 2005 "Urban 
Mobility Report" to identify states with congested urban areas; and by 
interviewing agency officials, association representatives, and 
reviewing studies and reports to determine states that had a higher 
level of experience planning and implementing various congestion 
mitigation techniques. We also interviewed officials in Aurora and 
Boulder, Colo; Altamonte Springs, Fla; Hampton Roads, Va;[Footnote 40] 
and Bellevue and Issaquah, Wash. to gain some insight into the 
implementation of congestion mitigation techniques in smaller 
jurisdictions. We also reviewed how other states have implemented 
congestion mitigation techniques, and we note these in this report. 

To identify the strategies that might be employed for addressing 
anticipated strains on infrastructure over the long term, we reviewed 
public and private sector research, studies, and proposals on the 
development of new long term strategies and built on the perspectives 
gained from our past work in transportation infrastructure and 
congestion. This was supplemented with interviews of officials in the 
Department of Transportation (DOT) and the Federal Highway 
Administration (FHWA) and stakeholders including the American 
Association of State Highway and Transportation Officials, Institute of 
Transportation Engineers, ITS America, and Environmental Defense. We 
conducted our work from September 2006 through July 2007 in accordance 
with generally accepted government auditing standards. 

[End of section] 

Appendix II: Congestion Mitigation Techniques and Benefits: 

Transportation agencies nationwide use a wide array of congestion 
mitigation techniques to manage congestion and maximize the existing 
transportation infrastructure. These techniques have the potential to 
provide benefits that improve efficiency by improving traffic flow, 
altering existing commuter patterns that cause congestion, and 
increasing the use of alternative transportation modes such as public 
transit and car pools. In general, these congestion mitigation 
techniques can be placed into two basic categories, techniques that are 
aimed at enhancing existing capacity, and techniques that influence 
driver behavior. 

Techniques that enhance capacity: These are techniques that are 
designed to increase the existing systems' capacity to improve travel 
flow. For example, incident management programs are designed to more 
rapidly deploy response vehicles that remove accident vehicles and 
debris and more quickly restore traffic flow after accidents. Table 2 
provides a brief description of selected congestion mitigation 
techniques designed to enhance capacity, and the potential benefit of 
each technique. 

Table 2: Selected Congestion Mitigation Techniques That Enhance 
Capacity: 

Technique: Traffic signal timing--coordinating the timing of a series 
of traffic signals along an arterial to reduce stops and move vehicles 
at a uniform speed; 
Benefit: Optimizing traffic signal timing increases vehicle speeds and 
traffic volumes and reduces accidents on major arterials. 

Technique: Incident management program--is a planned and coordinated 
program to detect, respond to, and remove traffic incidents; 
Benefit: Removing vehicles from the accident scene helps to reduce 
incident- related congestion and restore traffic capacity as safely and 
quickly as possible. 

Technique: Work zone management--using techniques such as warning 
signs, reversible lanes, and public awareness campaigns during road 
construction; 
Benefit: Use of work zone management techniques during road 
construction helps to minimize construction delays and related 
congestion. 

Technique: Bus, vanpool, and car pool lanes--setting aside dedicated 
high-occupancy vehicle (HOV) lanes for buses, vanpools, and car pools 
on freeways; 
Benefit: Dedicated lanes for buses, vanpools, and car pools provide a 
faster, more predictable travel time. By increasing the average number 
of people per vehicle, HOV lanes increase the overall capacity of the 
roadway. 

Technique: Access management--a set of techniques that state and local 
governments can use to control vehicle access to highways, major 
arterials, and other roadways, for example, limiting access to 
freeways, increasing the spacing between signals and interchanges, and 
use of frontage and service roads; 
Benefit: Techniques such as controlling signal spacing improves traffic 
flow and reduces congestion and accidents. 

Technique: Integrated corridor management--the operational coordination 
of specific transportation networks comprising a corridor, and the 
coordination of agencies responsible for corridor mobility; 
Benefit: Managing a corridor in an integrated manner is aimed at 
reducing travel times, improving travel predictability, and increasing 
transit ridership in the corridor. 

Technique: Asset management--a systematic process of maintaining, 
upgrading, and operating transportation assets cost effectively by 
applying engineering principles, sound business and economic practices, 
and a framework for planning and decision making; 
Benefit: An asset management program that includes regular maintenance 
and rehabilitation of roads can result in improved speed and 
reliability of passenger and freight travel. 

Source: GAO. 

[End of table] 

Techniques that influence driver behavior: These are techniques that 
are designed to reduce vehicle demand on the existing system by 
reducing the frequency of travel and travel during peak periods, 
altering the routes traveled, and providing incentives to use alternate 
transportation modes. For example, high-occupancy toll (HOT) lanes 
could charge single-occupancy vehicles a higher price during peak 
congestion times, and this provides incentives for drivers to travel at 
less congested times. Other policies, such as employer transit 
subsidies and flexible work schedule programs, can also shift drivers' 
use of the road network and thus reduce demand on the existing 
transportation infrastructure. Table 3 provides a brief description of 
selected congestion mitigation techniques designed to influence driver 
behavior and the potential benefit of each technique. 

Table 3: Select Congestion Mitigation Techniques That Influence Driver 
Behavior: 

Technique: High-occupancy toll (HOT) lanes--a priced lane that offers 
drivers of vehicles that do not meet the occupancy requirements the 
option of paying a toll to use lanes that are otherwise restricted to 
high-occupancy vehicles; 
Benefit: HOT lanes can channel traffic into underutilized lanes and 
decrease congestion on regular lanes thus increasing the overall 
throughput of a corridor. HOT lanes can also shift demand to less 
congested times by charging a lower toll just before and after peak 
period. 

Technique: Cordon-based pricing--a form of congestion pricing where 
drivers are charged a fee to enter a congested area such as a city 
center during peak periods; 
Benefit: Charging a fee to enter a central business district during 
peak periods encourages travelers to shift their behavior by either 
traveling at another time or by using alternative transportation modes 
such as buses and trains. 

Technique: Employer transit and vanpool subsidies--employers pay for 
employee monthly transit pass expenses; 
Benefit: Designed to provide an incentive for employees to use transit 
services resulting in reduced traffic demand on the road network. 

Technique: Real Time Traveler Information Web sites--Web sites that 
provide up-to-the-minute information on traffic conditions such as 
speeds, levels of congestion, and camera views of roads and incidents 
before the commuter starts out; 
Benefit: Providing information on congestion, commute times, and 
alternate routes allows a traveler to change time of departure, route, 
or mode of transport to avoid congestion and arrive at a destination in 
timely manner. 

Technique: Worksite flextime--allows employees to set their own arrival 
and departure time to/from work--within established time boundaries 
agreed to by their employer; 
Benefit: Encourages employees to avoid the most congested travel times, 
reducing the demand on roadway and/or transit systems during peak-
demand periods. 

Technique: Telework policies--allow employees to work at home during a 
portion of the workweek; 
Benefit: Working at home results in fewer trips to work and reduced 
demand on roads and transit systems. 

Technique: Land use and development policies and incentives--policies 
and incentives that encourage future growth near existing road and 
transit services; 
Benefit: Locating new residential development near existing transit 
facilities will make more efficient use of existing transit services 
with the potential to reduce demand on existing roads. 

Technique: Parking management--managing the supply and price of parking 
such as limiting the amount of single-occupancy parking spaces, 
charging higher parking fees, or providing preferential parking for car 
pools and vanpools; 
Benefit: Managing parking supply and price provides a disincentive for 
driving alone and an incentive for using alternate modes of travel. 

Source: GAO. 

[End of table] 

[End of section] 

Appendix III: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

JayEtta Z. Hecker, (202) 512-2834, heckerj@gao.gov: 

Staff Acknowledgments: 

In addition to the individual named above, Nikki Clowers, Assistant 
Director; Ashley Alley; Jay Cherlow; Anne Dilger; Brad Dubbs; Terence 
Lam; Maureen Luna-Long; Sara Ann Moessbauer; and Tim Schindler made key 
contributions to this report. 

FOOTNOTES 

[1] These interviews were conducted by telephone. 

[2] Janice J. Kim, et al., "Traffic-related Air Pollution near Busy 
Roads: The East Bay Children's Respiratory Health Study," American 
Journal of Respiratory and Critical Care Medicine 170 (2004); 520-526. 

[3] The remaining 9 percent was spent for system enhancements such as 
safety, operational, or environmental enhancements. 

[4] The composite bid price index is composed of six indicator items: 
common excavation, to indicate the price trend for all roadway 
excavation; Portland cement concrete pavement and bituminous concrete 
pavement, to indicate the price trend for all surfacing types; and 
reinforcing steel, structural steel, and structural concrete, to 
indicate the price trend for structures. The index is adjusted to 
account for inflation, so a doubling represents a substantial loss in 
purchasing power. 

[5] GAO, Performance and Accountability: Transportation Challenges 
Facing Congress and the Department of Transportation, GAO-07-545T 
(Washington, D.C.: Mar. 6, 2007); and GAO, Highway Trust Fund: Overview 
of Highway Trust Fund Estimates, GAO-06-572T (Washington, D.C.: Apr. 4, 
2006). 

[6] GAO, High Risk Series: An Update, GAO-07-310 (Washington, D.C.: 
January 2007). 

[7] Definitions of level of service are dependent on the specific road 
type, such as multilane highways or urban streets. There are other 
measures that are used such as travel time reliability. 

[8] More specifically, economists consider a road efficiently used 
when, at the margin, an additional driver using the road perceives his 
or her personal benefits to exactly offset both his or her personal 
costs, as well as other social costs, which include such costs as the 
additional travel time he or she imposes on other drivers, the wear and 
tear on the road surface, and the pollution to the society. Economists 
call this point as an equilibrium at which the marginal benefits to the 
additional user equal the marginal social costs. 

[9] One major FHWA program to mitigate work zone disruptions is the 
Highways for LIFE program. This program focuses on construction 
techniques, such as the use of prefabricated bridge and pavement 
elements and scheduling construction at night or on weekends that can 
reduce road closures, thereby limiting the impact of these events. 

[10] GAO, Highway and Transit Investments: Options for Improving 
Information on Projects' Benefits and Costs and Increasing 
Accountability for Results, GAO-05-172 (Washington, D.C.: Jan. 24, 
2005). 

[11] See also, Thomas M. Downs, "Is There a Future for the Federal 
Surface Transportation Program?", Journal of Transportation Engineering 
131, 6 (June 2005), and Ann Brach and Martin Wachs, "Earmarking in the 
U.S. Department of Transportation Research Programs," Transportation 
Research Part-A 39 (2005). Brach and Wachs observed that transportation 
research funds have been increasingly earmarked for specific 
institutions. 

[12] Clifford Winston and Ashley Langer, "The Effect of Government 
Highway Spending on Road Users' Congestion Costs," Journal of Urban 
Economics 60 (2006), argued that the current system allocates federal 
funding and state funding based partly on formulae which place great 
weight on the size of a state's road system and on a jurisdiction's 
road mileage, respectively. To allocate resources more efficiently, 
this system would need to be revised to be based more on the level of 
congestion and, even then, it is still not as effective as congestion 
pricing. 

[13] "HOT" lanes allow drivers who drive by themselves to pay to use 
less congested carpool lanes and thereby speed up their trips. 

[14] California, Colorado, Florida, Texas, Virginia, and Washington all 
have HOT lanes or have projects planned that will use variably priced 
tolls to alleviate congestion by managing the level of traffic. All of 
these states have received grants under FHWA's Value Pricing Pilot 
Program to either develop or implement the projects. 

[15] GAO, Surface Transportation: Many Factors Affect Investment 
Decisions, GAO-04-744 (Washington, D.C.: June 30, 2004). 

[16] Signal timing is one of many Intelligent Transportation System 
(ITS) technologies. ITS technologies use communications, electronics, 
sensors, and computer hardware and software to improve the performance 
and safety of freeways, roads, and transit systems. Other congestion 
mitigation techniques using ITS technologies include traffic cameras, 
message signs, traveler information Web sites, traffic sensors, ramp 
meters, and electronic toll collection systems. See GAO, Highway 
Congestion: Intelligent Transportation Systems' Promise for Managing 
Congestion Falls Short, and DOT Could Better Facilitate Their Strategic 
Use, GAO-05-943 (Washington, D.C.: Sept. 14, 2005). 

[17] For example, the occupancy requirement for some HOV lanes is at 
least three people; in these instances, a HOT lane would allow a 
vehicle with two people to use the lane if the driver pays a toll. 

[18] As we reported in 2005 in our review of ITS projects, though 
studies of ITS projects have found positive impacts, most of the 
studies we reviewed did not include information on the cost 
effectiveness of the ITS project, such as benefit-cost analyses (see 
GAO-05-943). 

[19] Long-range plans identify transportation needs for the next 20 
years. Short-term transportation plans, called Transportation 
Improvement Programs (TIP), describe projects selected to support long- 
range transportation plan goals. Federal law requires that, within 
these plans, each metropolitan planning organization consider at least 
seven factors, one of which is to promote efficient system management 
and operation. 

[20] Development impact fees are payments made by developers for the 
cost of additional infrastructure necessary as a result of the new 
development. 

[21] FHWA is working with the National Transportation Operations 
Coalition (NTOC) and state and local governments on an ongoing project 
to develop a common set of operations performance measures and 
definitions. FHWA officials stated that piloting of the measures will 
take place as part of a National Cooperative Highway Research Program 
(NCHRP) study in 2007, with results expected in early 2008. 

[22] Institute of Transportation Engineers, Action Kit: Immediate 
Solutions for Transportation Operational Issues (Washington, D.C.: 
2005); American Association of State Highway and Transportation 
Officials, Future Needs of the U.S. Surface Transportation System 
(February 2007); Cambridge Systematics, Traffic Congestion and 
Reliability: Linking Solutions to Problems (Cambridge, MA: July 19, 
2004); Cambridge Systematics, Traffic Congestion and Reliability: 
Trends and Advanced Strategies for Congestion Mitigation (Cambridge, 
MA: Sept. 1, 2005); Transportation Research Board, Performance Measures 
to Improve Transportation Systems: Summary of Second National 
Conference (Washington, D.C.: 2005); Transportation Research Board, 
Linking Transportation and Land Use: A Peer Exchange (Washington, D.C.: 
July 2006). 

[23] See our forthcoming report on public-private partnerships that 
will discuss in further detail the potential benefits and significant 
risks, and steps that must be taken to protect the public interest. 
This report is estimated to be published in the fall of 2007. 

[24] The VII Consortium is a nonprofit organization that is open to all 
vehicle manufacturers. Currently, the consortium membership includes 
BMW, Daimler Chrysler, Ford, GM, Honda, Nissan, Toyota, and VW. 

[25] Some states are also increasingly funding transportation projects 
with alternative mechanisms that are not user-pay based. For example, 
some states are using revenues from sales taxes and the state's general 
fund for transportation projects. 

[26] The study will be conducted by University of Iowa Public Policy 
Center. 

[27] Oregon officials shared some preliminary observations with us in 
advance of the study's completion. Their preliminary conclusions were 
that the pilot project's successes were in the areas of zone 
differentiation (that is the counting devices was able to distinguish 
with accuracy when the car traveled into or out of different 
preprogrammed zones), mileage counting accuracy, transaction 
administration integration with gas tax collections, and mileage data 
transmission accuracy at the fuel pump. The largest lesson learned is 
that retrofitting of existing vehicles with mileage counting technology 
is highly problematic because technology applications for various 
vehicle makes and models are not standardized. 

[28] See GAO, Marine Transportation: Federal Financing and a Framework 
for Infrastructure Investments, GAO-02-1033 (Washington, D.C.: Sept. 9, 
2002); GAO, Freight Transportation: Strategies Needed to Address 
Planning and Financing Limitations, GAO-04-165 (Washington, D.C.: Dec. 
19, 2003); and GAO-05-172. 

[29] Transportation asset management, which is a systematic process of 
maintaining, upgrading, and operating transportation assets, is one 
type of technique that incorporates many of the concepts of a 
performance-based approach. 

[30] Pub. L. No. 109-59, § 3011(a), codified at 49 U.S.C. § 
5309(g)(2)(C). 

[31] National Transportation Operations Coalition, "National Traffic 
Signal Report Card: Technical Report," 2005. A total of 378 respondents 
fully completed the self-assessment. The number of signals represented 
by responding agencies corresponds to about one-third of all signals in 
the United States. 

[32] National Cooperative Highway Research Program, Synthesis 377: 
Cooperative Agreements for Corridor Management (Washington, D.C.: 
2004). 

[33] The Urban Land Institute defines smart growth as development that 
is environmentally sensitive, economically viable, community-oriented, 
and sustainable. 

[34] See GAO, Highway Finance: States' Expanding Use of Tolling 
Illustrates Diverse Challenges and Strategies, GAO-06-554 (Washington, 
D.C.: June 28, 2006). 

[35] See GAO-05-172. 

[36] States have broad flexibility to transfer funds between the 
various federal-aid grant programs. For example, states may transfer up 
to 50 percent of their Interstate Maintenance and National Highway 
System Program funds to other programs, including the Surface 
Transportation Program, which has broad eligibility rules. In addition, 
authorizing statutes, most recently amended by SAFETEA-LU, provided the 
states broad authority to transfer federal-aid Highway funds to transit 
projects and vice versa. 

[37] The Federal Transit Administration (FTA) issued guidance on the 
terms and conditions on which FTA will classify HOV lanes that are 
converted to HOT lanes as "fixed guideway miles" for purposes of the 
transit funding formulas administered by FTA. 

[38] GAO, Intermodal Transportation: Potential Strategies Would 
Redefine Federal Role in Developing Airport Intermodal Capabilities, 
GAO-05-727 (Washington, D.C.: July 26, 2005); and GAO, Freight 
Transportation: Short Sea Shipping Option Shows Importance of 
Systematic Approach to Public Investment Decisions, GAO-05-768 
(Washington, D.C.: July 29, 2005). 

[39] These interviews were conducted by telephone. 

[40] These interviews were conducted by telephone. 

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