Surface Transportation
Strategies Are Available for Making Existing Road Infrastructure Perform Better
Gao ID: GAO-07-920 July 26, 2007
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.
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.
GAO-07-920, Surface Transportation: Strategies Are Available for Making Existing Road Infrastructure Perform Better
This is the accessible text file for GAO report number GAO-07-920
entitled 'Surface Transportation: Strategies Are Available for Making
Existing Road Infrastructure Perform Better' which was released on July
26, 2007.
This text file was formatted by the U.S. Government Accountability
Office (GAO) to be accessible to users with visual impairments, as part
of a longer term project to improve GAO products' accessibility. Every
attempt has been made to maintain the structural and data integrity of
the original printed product. Accessibility features, such as text
descriptions of tables, consecutively numbered footnotes placed at the
end of the file, and the text of agency comment letters, are provided
but may not exactly duplicate the presentation or format of the printed
version. The portable document format (PDF) file is an exact electronic
replica of the printed version. We welcome your feedback. Please E-mail
your comments regarding the contents or accessibility features of this
document to Webmaster@gao.gov.
This is a work of the U.S. government and is not subject to copyright
protection in the United States. It may be reproduced and distributed
in its entirety without further permission from GAO. Because this work
may contain copyrighted images or other material, permission from the
copyright holder may be necessary if you wish to reproduce this
material separately.
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.
GAO's Mission:
The Government Accountability Office, the audit, evaluation and
investigative arm of Congress, exists to support Congress in meeting
its constitutional responsibilities and to help improve the performance
and accountability of the federal government for the American people.
GAO examines the use of public funds; evaluates federal programs and
policies; and provides analyses, recommendations, and other assistance
to help Congress make informed oversight, policy, and funding
decisions. GAO's commitment to good government is reflected in its core
values of accountability, integrity, and reliability.
Obtaining Copies of GAO Reports and Testimony:
The fastest and easiest way to obtain copies of GAO documents at no
cost is through GAO's Web site (www.gao.gov). Each weekday, GAO posts
newly released reports, testimony, and correspondence on its Web site.
To have GAO e-mail you a list of newly posted products every afternoon,
go to www.gao.gov and select "Subscribe to Updates."
Order by Mail or Phone:
The first copy of each printed report is free. Additional copies are $2
each. A check or money order should be made out to the Superintendent
of Documents. GAO also accepts VISA and Mastercard. Orders for 100 or
more copies mailed to a single address are discounted 25 percent.
Orders should be sent to:
U.S. Government Accountability Office 441 G Street NW, Room LM
Washington, D.C. 20548:
To order by Phone: Voice: (202) 512-6000 TDD: (202) 512-2537 Fax: (202)
512-6061:
To Report Fraud, Waste, and Abuse in Federal Programs:
Contact:
Web site: www.gao.gov/fraudnet/fraudnet.htm E-mail: fraudnet@gao.gov
Automated answering system: (800) 424-5454 or (202) 512-7470:
Congressional Relations:
Gloria Jarmon, Managing Director, JarmonG@gao.gov (202) 512-4400 U.S.
Government Accountability Office, 441 G Street NW, Room 7125
Washington, D.C. 20548:
Public Affairs:
Paul Anderson, Managing Director, AndersonP1@gao.gov (202) 512-4800
U.S. Government Accountability Office, 441 G Street NW, Room 7149
Washington, D.C. 20548: