Surface Transportation: Strategies Are Available for Making
Existing Road Infrastructure Perform Better (26-JUL-07,
GAO-07-920).
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.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-07-920
ACCNO: A73393
TITLE: Surface Transportation: Strategies Are Available for
Making Existing Road Infrastructure Perform Better
DATE: 07/26/2007
SUBJECT: Highway traffic control systems
Program evaluation
Public roads or highways
Strategic planning
Traffic regulation
Transportation costs
Transportation planning
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GAO-07-920
* [1]Results in Brief
* [2]Background
* [3]Pressure on Road System Continues to Build
* [4]Capacity Has Not Kept Pace with Demand, and Is Not Likely to
* [5]With Capacity Constrained, Other Approaches Are Receiving Mo
* [6]Federal Government Is One of Many Stakeholders in Operating
* [7]Three Broad Factors Inhibit Efficient Use of Roads
* [8]Road Network's Design and Operation Fail to Adapt to Changin
* [9]Traditional Funding Structure Does Not Provide Incentives fo
* [10]Current Investment Decision-Making Process Has a Limited Foc
* [11]Various Techniques Have Been Developed to Make the Current I
* [12]Transportation Decision Makers Are Using Similar Approaches
* [13]Officials Report Giving Congestion Mitigation Techniques Mor
* [14]Setting Goals That Incorporate Congestion Mitigation
* [15]Modifying Project Selection Process to Emphasize
Congestion
* [16]Restructuring Organizations to Align with Transportation
Pla
* [17]Adopting Policies or Regulations That Promote Congestion
Mit
* [18]Agencies Report Developing New Methods to Fund the Use of Co
* [19]Imposing Tolls, Local Taxes, or Development Impact Fees
* [20]Developing Partnerships with Private Industry
* [21]Designating Specific Funding within Existing Resources
* [22]Transportation Agencies Are Collaborating with Multiple Stak
* [23]Persistent Issues Keep Congestion Mitigation Techniques from
* [24]Various Strategies Exist for Increasing the Efficient Use of
* [25]Three Strategies Crosscut All Levels of Governments
* [26]Consider How the Private Sector Can Be Used in Managing
Exis
* [27]Expand the Use of the User-Pay Concept
* [28]Measure Results and Manage the Existing Infrastructure
with
* [29]Several Strategies Relate Mainly to State and Local Governme
* [30]Implement a Combination of Supply-Related and
Demand-Related
* [31]Apply Congestion Mitigation Techniques on a Regional
Basis
* [32]Integrate Transportation Planning More Fully with
Land-Use P
* [33]Building Support for Congestion Mitigation Techniques
* [34]Several Strategies Relate Mainly to the Federal Government t
* [35]Link Federal-Aid Highway Funding to Performance
* [36]Increase Flexibility to State and Local Decision Makers
* [37]Placing Additional Focus on Projects That Provide
National P
* [38]Concluding Observations
* [39]Agency Comments and Our Evaluation
* [40]Appendix I: Objectives, Scope, and Methodology
* [41]Appendix II: Congestion Mitigation Techniques and Benefits
* [42]Appendix III: GAO Contact and Staff Acknowledgments
* [43]GAO Contact
* [44]Staff Acknowledgments
* [45]Order by Mail or Phone
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
Contents
Letter 1
Results in Brief 3
Background 5
Three Broad Factors Inhibit Efficient Use of Roads 13
Various Techniques Have Been Developed to Make the Current Infrastructure
More Efficient 18
Transportation Decision Makers Are Using Similar Approaches for
Implementing Congestion Mitigation Techniques, but Challenges Exist 24
Various Strategies Exist for Increasing the Efficient Use of
Infrastructure 32
Concluding Observations 43
Agency Comments and Our Evaluation 44
Appendix I Objectives, Scope, and Methodology 46
Appendix II Congestion Mitigation Techniques and Benefits 48
Appendix III GAO Contact and Staff Acknowledgments 51
Tables
Table 1: Examples of Long-range and Short-range Transportation Plans at
Locations GAO Visited 25
Table 2: Selected Congestion Mitigation Techniques That Enhance Capacity
48
Table 3: Select Congestion Mitigation Techniques That Influence Driver
Behavior 49
Figures
Figure 1: Percentage Change of Vehicle Miles Traveled and New Construction
of Lane Miles between 1980 and 2005 7
Figure 2: Representation of Levels of Service on a Two-Lane Highway 10
Figure 3: Percentage of Highway Capacity That Is Reduced When Vehicle
Incidents Occur 15
Figure 4: Select Congestion Management Techniques that Enhance Capacity
and Influence Driver Behavior and Demand 21
Figure 5: Express Lanes and General Purpose Lanes on State Route 91 in
Orange County, California 23
Figure 6: Florida Road Ranger Incident Response Vehicle 29
Figure 7: Strategies for Making More Efficient Use of Existing
Infrastructure 33
Figure 8: Representation of the VII Mobility Applications 35
Figure 9: Minnesota's "MnPass" Program 41
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
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separately.
United States Government Accountability Office
Washington, DC 20548
July 26, 2007 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. 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 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,^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.)
^1These interviews were conducted by telephone.
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.^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.)
^2Janice 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.
Figure 1: Percentage Change of Vehicle Miles Traveled and New Construction
of Lane Miles between 1980 and 2005
Note: Index = 1 for 1980.
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.
o 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.
o 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.^3 In 1993, 45
percent of the total was spent on system preservation.
o 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^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.
o 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.^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.^6
^3The remaining 9 percent was spent for system enhancements such as
safety, operational, or environmental enhancements.
^4The 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.
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.
o 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"^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.
^5GAO, Performance and Accountability: Transportation Challenges Facing
Congress and the Department of Transportation, [46]GAO-07-545T
(Washington, D.C.: Mar. 6, 2007); and GAO, Highway Trust Fund: Overview of
Highway Trust Fund Estimates, [47]GAO-06-572T (Washington, D.C.: Apr. 4,
2006).
^6GAO, High Risk Series: An Update, [48]GAO-07-310 (Washington, D.C.:
January 2007).
^7Definitions 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.
Figure 2: Representation of Levels of Service on a Two-Lane Highway
o 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.^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.
^8More 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.
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.
o 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.
o 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.
o 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.
o 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.
o 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.^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.
^9One 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.
Figure 3: Percentage of Highway Capacity That Is Reduced When Vehicle
Incidents Occur
Note: The percentages are estimates for three-lane highways only and may
vary with actual circumstances.
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:
o 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.
o 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.
o 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.
o Funding is compartmentalized by transportation mode. Many
transportation experts maintain--and our past work^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.^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.^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)^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.^14
^10GAO, Highway and Transit Investments: Options for Improving Information
on Projects' Benefits and Costs and Increasing Accountability for Results,
[49]GAO-05-172 (Washington, D.C.: Jan. 24, 2005).
^11See 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.
^12Clifford 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.
o 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.^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.^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.
^14California, 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.
^15GAO, Surface Transportation: Many Factors Affect Investment Decisions,
[50]GAO-04-744 (Washington, D.C.: June 30, 2004).
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.^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.
^16Signal 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, [51]GAO-05-943
(Washington, D.C.: Sept. 14, 2005).
^17For 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.
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
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.^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:
o 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.
o 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.
o 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).
^18As 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 [52]GAO-05-943 ).
Figure 5: Express Lanes and General Purpose Lanes on State Route
91 in Orange County, California
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:
o 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.
o 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.
o 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.^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.
^19Long-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.
Table 1: Examples of Long-range and Short-range Transportation Plans at
Locations GAO Visited
Added emphasis on managing existing infrastructure more
Location efficiently
San Diego, CA 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.
Orlando, FL 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.
Seattle, WA 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.
Denver, CO 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.
Bellevue, WA 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.
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:
o 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.
o 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.
o 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.^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.
^20Development impact fees are payments made by developers for the cost of
additional infrastructure necessary as a result of the new development.
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:
o 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.
o 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.
o 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
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:
o 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.
o 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.
o 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.^21
o 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.
o 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.
^21FHWA 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.
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.^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.
^22Institute 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).
Figure 7: Strategies for Making More Efficient Use of Existing
Infrastructure
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.^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^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.
^23See 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.
^24The 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.
Figure 8: Representation of the VII Mobility Applications
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.
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.^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,^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.^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,^28 a performance-based management approach for transportation
would include establishing performance targets, developing performance
measures, and enhancing data quality.^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.^30
^25Some 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.
^26The study will be conducted by University of Iowa Public Policy Center.
^27Oregon 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.
^28See GAO, Marine Transportation: Federal Financing and a Framework for
Infrastructure Investments, [53]GAO-02-1033 (Washington, D.C.: Sept. 9,
2002); GAO, Freight Transportation: Strategies Needed to Address Planning
and Financing Limitations, [54]GAO-04-165 (Washington, D.C.: Dec. 19,
2003); and [55]GAO-05-172 .
^29Transportation 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.
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.
^30Pub. L. No. 109-59, S 3011(a), codified at 49 U.S.C. S 5309(g)(2)(C).
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.^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^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.
^31National 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.
^32National Cooperative Highway Research Program, Synthesis 377:
Cooperative Agreements for Corridor Management (Washington, D.C.: 2004).
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.^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^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.
^33The Urban Land Institute defines smart growth as development that is
environmentally sensitive, economically viable, community-oriented, and
sustainable.
^34See GAO, Highway Finance: States' Expanding Use of Tolling Illustrates
Diverse Challenges and Strategies, [56]GAO-06-554 (Washington, D.C.: June
28, 2006).
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).
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.^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.
^35See [57]GAO-05-172 .
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.^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.^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.
^36States 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.
^37The 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.
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,^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.
^38GAO, Intermodal Transportation: Potential Strategies Would Redefine
Federal Role in Developing Airport Intermodal Capabilities, [58]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, [59]GAO-05-768 (Washington, D.C.: July 29, 2005).
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
[60]http://www.gao.gov .
If you have any questions about this report, please contact me at
[61][email protected] 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,
JayEtta Z. Hecker
Director, Physical Infrastructure Issues
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.;^1
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.;^2 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.
^1These interviews were conducted by telephone.
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.
^2These interviews were conducted by telephone.
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 Benefit
Traffic signal timing--coordinating the Optimizing traffic signal timing
timing of a series of traffic signals increases vehicle speeds and
along an arterial to reduce stops and traffic volumes and reduces
move vehicles at a uniform speed. accidents on major arterials.
Incident management program--is a planned Removing vehicles from the
and coordinated program to detect, accident scene helps to reduce
respond to, and remove traffic incidents. incident-related congestion and
restore traffic capacity as
safely and quickly as possible.
Work zone management--using techniques Use of work zone management
such as warning signs, reversible lanes, techniques during road
and public awareness campaigns during construction helps to minimize
road construction. construction delays and related
congestion.
Bus, vanpool, and car pool lanes--setting Dedicated lanes for buses,
aside dedicated high-occupancy vehicle vanpools, and car pools provide
(HOV) lanes for buses, vanpools, and car a faster, more predictable
pools on freeways. travel time. By increasing the
average number of people per
vehicle, HOV lanes increase the
overall capacity of the roadway.
Access management--a set of techniques Techniques such as controlling
that state and local governments can use signal spacing improves traffic
to control vehicle access to highways, flow and reduces congestion and
major arterials, and other roadways, for accidents.
example, limiting access to freeways,
increasing the spacing between signals
and interchanges, and use of frontage and
service roads.
Integrated corridor management--the Managing a corridor in an
operational coordination of specific integrated manner is aimed at
transportation networks comprising a reducing travel times, improving
corridor, and the coordination of travel predictability, and
agencies responsible for corridor increasing transit ridership in
mobility. the corridor.
Asset management--a systematic process of An asset management program that
maintaining, upgrading, and operating includes regular maintenance and
transportation assets cost effectively by rehabilitation of roads can
applying engineering principles, sound result in improved speed and
business and economic practices, and a reliability of passenger and
framework for planning and decision freight travel.
making.
Source: GAO.
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 Benefit
High-occupancy toll (HOT) lanes--a HOT lanes can channel traffic into
priced lane that offers drivers of underutilized lanes and decrease
vehicles that do not meet the occupancy congestion on regular lanes thus
requirements the option of paying a increasing the overall throughput
toll to use lanes that are otherwise of a corridor. HOT lanes can also
restricted to high-occupancy vehicles. shift demand to less congested
times by charging a lower toll
just before and after peak period.
Cordon-based pricing--a form of Charging a fee to enter a central
congestion pricing where drivers are business district during peak
charged a fee to enter a congested area periods encourages travelers to
such as a city center during peak shift their behavior by either
periods. traveling at another time or by
using alternative transportation
modes such as buses and trains.
Employer transit and vanpool Designed to provide an incentive
subsidies--employers pay for employee for employees to use transit
monthly transit pass expenses. services resulting in reduced
traffic demand on the road
network.
Real Time Traveler Information Web Providing information on
sites--Web sites that provide congestion, commute times, and
up-to-the-minute information on traffic alternate routes allows a traveler
conditions such as speeds, levels of to change time of departure,
congestion, and camera views of roads route, or mode of transport to
and incidents before the commuter avoid congestion and arrive at a
starts out. destination in timely manner.
Worksite flextime--allows employees to Encourages employees to avoid the
set their own arrival and departure most congested travel times,
time to/from work--within established reducing the demand on roadway
time boundaries agreed to by their and/or transit systems during
employer. peak-demand periods.
Telework policies--allow employees to Working at home results in fewer
work at home during a portion of the trips to work and reduced demand
workweek. on roads and transit systems.
Land use and development policies and Locating new residential
incentives--policies and incentives development near existing transit
that encourage future growth near facilities will make more
existing road and transit services. efficient use of existing transit
services with the potential to
reduce demand on existing roads.
Parking management--managing the supply Managing parking supply and price
and price of parking such as limiting provides a disincentive for
the amount of single-occupancy parking driving alone and an incentive for
spaces, charging higher parking fees, using alternate modes of travel.
or providing preferential parking for
car pools and vanpools.
Source: GAO.
Appendix III: GAO Contact and Staff Acknowledgments
GAO Contact
JayEtta Z. Hecker, (202) 512-2834, [email protected]
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.
(544129)
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[68]www.gao.gov/cgi-bin/getrpt?GAO-07-920 .
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Highlights of [69]GAO-07-920 , a report to the Ranking Member, Committee
on Environment and Public Works, U.S. Senate
July 2007
SURFACE TRANSPORTATION
Strategies Are Available for Making Existing Road Infrastructure Perform
Better
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.
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.
Examples of Various Congestion Mitigation Techniques
References
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63. http://www.gao.gov/
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67. mailto:[email protected]
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69. http://www.gao.gov/cgi-bin/getrpt?GAO-07-920
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