Traffic Congestion: Road Pricing Can Help Reduce Congestion, but Equity Concerns May Grow
Published: 2012-01-12T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: Many Americans spend frustrating hours each year stuck in traffic. While estimates vary, the Department of Transportation (DOT) estimates that traffic congestion costs the United States $200 billion each year, and that more than one-quarter of total annual travel time in metropolitan areas occurs in congested conditions. Road pricing or congestion pricingassessing tolls that vary with the level of congestion or time of dayaims to motivate drivers to share rides, use transit, travel at less congested times, or pay to use tolled lanes. Since the first U.S. congestion pricing project opened in 1995, 19 project sponsors have 41 pricing projects in operation or under construction. About 400 miles of priced highway lanes including nearly 150 miles on the New Jersey Turnpike are in operation today with current tolls varying from 25 cents to $14.
All U.S. projects in operation are either High Occupancy Toll (HOT) lanes, which charge solo drivers to use newly constructed lanes or carpool lanes, or peak-period pricing projects, which charge a lower toll on already tolled roads, bridges and tunnels during offpeak periods. GAO examined (1) the federal role in supporting congestion pricing, (2) results of U.S. congestion pricing projects, and (3) emerging issues in congestion pricing. Eight project sponsors have current and completed evaluations on at least 1 project, for a total of 14 evaluated projects, all of which GAO reviewed. GAO interviewed officials about the performance of their pricing projects and effects. DOT provided technical comments, which GAO incorporated as appropriate.
section_title: What GAO Found
paragraphs: DOT approves all congestion pricing projects on roadways that receive federal funds and provides grants for project studies, implementation, and evaluation. Nearly all HOT lane projects and most peak-period pricing projects in operation today received federal funds at one time or another. DOTs largest programs for congestion relief, the Urban Partnership Agreement and Congestion Reduction Demonstration programs, have provided grant funds totaling nearly $800 million since 2006 to six metropolitan areas to implement pricing and other strategies. DOT requires sponsors of congestion pricing projects to monitor and evaluate performance and, for HOT lanes when applicable, ensure that a federal standard for minimum traffic speeds is met.
The 14 congestion pricing projects that have current and complete evaluations generally show that pricing can help reduce congestion, although other results are mixed, and not all possible relevant impacts have been assessed. HOT lane projects, which aim to reduce congestion by decreasing travel time and increasing speed and the number of vehicles using the lane, have reduced congestion, but some HOT lane projects also added new lanes, and studies did not distinguish the extent to which performance improvements were due to added lanes or pricing. In addition, although the number of cars using HOT lanes has risen, there were fewer people in those cars because of an increase in the proportion of toll-paying solo drivers or a decrease in carpools. Peak-period pricing projects, which aim to reduce congestion by encouraging drivers to travel at off-peak times, have shifted some travel to those times. Other congestion pricing effectssuch as equity income impactshave not always been evaluated. Potential concerns include income equity (whether low-income drivers are disproportionately affected by congestion pricing) and geographic equity (whether one geographic area is more negatively affected than another, such as when traffic diversion occurs). These impacts are important to assess as they address the public and elected officials concerns about the effects of pricing on travelers and communities. Ongoing multi-year evaluations across six metropolitan areas will assess the performance and effects of congestion pricing projects using a specific set of measures to assess the effectiveness of congestion reduction strategies.
Concerns about equity may grow as pricing projects become more widespread. New projects are under construction, and several metropolitan areas have networks of HOT lanes planned that will expand the relatively limited use of pricing today. Equity concerns may become more acute where sponsors are using pricing not only to manage congestion, but also to raise revenue to build new projects. Raising revenue can be at odds with managing congestion (e.g., increasing passenger throughput) if higher tolls can produce more revenue from fewer paying vehicles. Options to address equity issues include using a portion of toll revenues to finance public transit service.

section_title: Letter
paragraphs: Many Americans spend frustrating hours each year stuck in congested  traffic, a situation that costs the country billions of dollars annually and  influences people’s decisions about where to live and work. As traffic has  risen dramatically over the past 3 decades with population and economic  growth, congestion now extends to more times of the day, more roads,  and more cities and towns—thus affecting more people than ever before.  Estimates of the cost of congestion vary; according to the Department of  Transportation (DOT), congestion costs America an estimated $200  billion each year in lost travel time and fuel, and drivers in metropolitan  areas spent more than one-quarter of their total annual travel time in  congested conditions.
Metropolitan areas have undertaken several approaches to reduce  congestion, but some approaches are becoming impractical and too  costly. For example, metropolitan areas have widened or extended roads  to add physical capacity, yet this option may not be feasible in some  densely populated urban areas or could have significant social and  environmental impacts. Furthermore, adding roadway capacity is costly at  a time when governments at all levels are facing fiscal constraints.  Metropolitan areas have also attempted to reduce congestion by  managing existing infrastructure more efficiently, through traffic  management strategies such as timed traffic signals, signs that warn  drivers of congestion ahead, and improved responses to accidents. Other  strategies, such as carpool or bus-only lanes, have been designed to  reduce the number of vehicles on roadways by encouraging people not to  drive alone.
Another strategy to reduce congestion is road pricing or congestion  pricing—assessing tolls that vary with the level of congestion and time of  day. Since the first U.S. congestion pricing project opened in 1995, 19  project sponsors, generally state departments of transportation or local  authorities, have 41 pricing projects either operational or under  construction—primarily charging solo drivers to pay a toll on newly  constructed lanes, existing carpool lanes, or charging a lower toll on tolled  highways, bridges, and tunnels during off-peak periods. Concerns on the  part of public and elected officials about the fairness of congestion pricing  to all users have, however, been a challenge to instituting these projects.
At your request, we examined (1) the federal role in supporting  congestion pricing, (2) results of congestion pricing projects in the United  States, and (3) emerging issues in congestion pricing projects. To  address these objectives, we reviewed relevant legislation, literature,  reports, and studies. We interviewed federal officials who oversee  programs related to congestion pricing as well as experts in the field. We  analyzed congestion pricing project performance from evaluations,  related environmental and traffic diversion assessments, traveler surveys,  and interviews with state and local transportation officials who have  implemented and evaluated projects. See appendix I for our study  objectives, scope, and methodology.
We conducted this performance audit from October 2010 through January  2012 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  that the evidence obtained provides a reasonable basis for our findings  and conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: Traffic congestion is caused by more vehicles on a road than it is  designed to accommodate, and it can be exacerbated by several factors.  For example, bottlenecks at highway interchanges or on bridges and  tunnels can worsen congestion. Vehicles traveling at different speeds can  increase the average amount of space between cars, thus not efficiently  using all space available in a lane. Stop-and-go traffic leads to increased  queuing and periodic events such as traffic accidents and roadway  construction can compound already congested conditions. Although a  transportation system is designed to handle a certain number of vehicles,  the flow of traffic can be improved at certain times and places such as  during rush hours or at bottlenecks.
Congestion pricing is designed to improve the flow of traffic by charging  drivers a toll that can vary with the level of congestion or time of day.  Drivers pay a higher price for using a lane or roadway at times of heavy  traffic, and a lower price when and where traffic is light. To avoid toll  payment, drivers may choose to share rides, use transit, travel at less  congested (generally off-peak) times, or travel on less congested routes.  Drivers who place a high value on time may choose to pay the toll to use  the priced lane during congested times in return for a faster and more  reliable trip. Alternatively, drivers who wish to pay a discounted toll on an  already tolled roadway can travel at off-peak times.
Economists generally believe that congestion pricing has the potential to  alleviate congestion on roadways in an economically efficient way. Those  who value a fast and reliable trip will pay for the option. Drivers who place  a lower value on time will choose to stay in the unpriced and potentially  more congested roadways. Economists believe that congestion pricing  can also enhance economic efficiency by making drivers take into  account the external costs they impose on others when making their  travel choices. Any given driver’s highway use entails extra costs that the  driver does not bear, in the form of congestion, noise, and pollution. Thus,  paying a toll that reflects a driver’s value of time and covers external costs  can potentially reduce congestion and the demand for road space at peak  periods. We have reported that the existing infrastructure can be  managed more efficiently and that congestion pricing could be one  method to do so.
All congestion pricing projects in the United States have used either (1)  High Occupancy Toll (HOT) lanes or (2) peak-period pricing on already  tolled facilities. HOT lanes have been created by constructing new lanes  or converting existing carpool or High Occupancy Vehicle (HOV) lanes,  some of which had been previously underused, and allowing solo drivers  to use these lanes if they pay a toll. Users of the prior HOV-only lanes,  such as carpools and express buses, generally continue to use the lanes  for free and are allowed to use newly constructed HOT lanes for free as  well. HOT lane operators seek to influence the number of vehicles in the  HOT lane and maintain 45- to 55-mile-per-hour travel speeds through  “dynamic” pricing—that is, increasing or decreasing tolls in real time  depending on traffic in the HOT lane. Peak-period pricing on already  tolled highways, bridges, and tunnels or on new or planned replacement  facilities is another type of congestion pricing project in the United States.  In this type of pricing, tolls are fixed higher during peak travel times and  lower during off-peak times to encourage drivers to use the roadway off- peak. Three HOT lane projects have used a hybrid approach to dynamic  and peak-period pricing called “variable” pricing. Variable pricing uses a  pre-set schedule of tolls that is periodically revised to account for changes  in congestion or other factors.
Since the first U.S. congestion pricing project was implemented in Orange  County, California, in 1995, 19 project sponsors have initiated 41 pricing  projects on highways, bridges, and tunnels. Projects operate in Georgia,  Utah, Colorado, Maryland, and New Jersey with multiple projects in  California, Florida, New York, Texas, Virginia, Minnesota, and  Washington State. Of the 41 pricing projects, 30 are completed and open  to traffic. The 30 opened projects include 12 HOT lane projects and 18  peak-period priced facilities, covering about 400 miles of priced lanes.  Projects range in length from 4.1 miles on the State Route (SR) 133 in  Orange County, California, to nearly 150 miles on the New Jersey  Turnpike, and charge tolls varying from 25 cents to $14. Eleven HOT  lane projects are under construction; in addition, 2 of the 12 HOT lane  projects in operation are extending the length of their tolled lanes. Figure  1 shows congestion pricing projects in operation and under construction  including extensions to existing projects. Appendix II provides additional  details on congestion pricing projects and toll rates.
More metropolitan areas across the country are using or plan to use  pricing as a way to relieve congestion on highways and bridges, and  some regions are planning to implement networks of HOT lanes. Dallas- Ft. Worth, Atlanta, Minneapolis-St. Paul, Seattle, and the San Francisco  Bay Area have networks of HOT lanes in their long-term plans. For  example, the Metropolitan Transportation Commission of the San  Francisco Bay Area proposes to add a 570-mile HOT lane network by  2025 as part of its 35-year regional plan. The Washington State  Department of Transportation proposes to convert carpool lanes to HOT  lanes on nearly 300 miles in the Seattle/Puget Sound area. Such  networks are also being considered in Los Angeles, Washington, D.C.,  and the Miami-Ft. Lauderdale area.
Congestion pricing has raised equity concerns among the public and  elected officials. In general, an analysis of equity issues examines how  costs and benefits of projects are distributed among members of society. In  the transportation economics literature, four concepts of equity are cited.
The extent to which members of the same group are treated equally;  for example, whether some people with the same income pay a larger  amount in taxes or fees.
The extent to which those who benefit from a project, such as a new  lane, pay for those benefits; for example, is the lane paid for by a toll  on users or by a state sales tax paid in part by persons who may not  use or benefit from the lane?
How the costs and benefits of a project are distributed across  members of different groups such as high- and low-income people; for  example, whether all groups pay in proportion to their income or  whether low-income people pay proportionally more of their income  for tolls than high-income people.
The extent to which those who impose social costs bear those costs;  for example, whether polluters or drivers on crowded highways pay  the full social cost of their driving, or, if a toll causes diversion from the  tolled highway to adjacent neighborhoods, those neighborhoods incur  the costs of pollution and crowding.
While recognizing that all of these concepts of equity cited in the literature  may be important, public and elected officials’ concerns regarding  congestion pricing have been primarily with the latter two concepts of  equity, in particular, what is termed income equity and geographic equity.
Income equity refers to whether the costs of congestion pricing that  users incur are proportional to their incomes, or whether low-income  drivers are disproportionately affected. For example, low-income  drivers may spend a greater proportion of their income to pay to travel  at preferred times or incur greater costs in travel time by choosing  alternate unpriced routes. High-income drivers, who, economists  generally believe, place a higher value on their time, may be more  likely to pay the toll and benefit from a faster trip than low-income  drivers, thus possibly generating income equity concerns.
Geographic equity refers to how equally the costs and benefits  associated with congestion pricing are distributed within an affected  metropolitan area. For example, if one corridor in a metropolitan area  has congestion pricing and another does not, drivers in the tolled  corridor may incur greater costs than drivers in the untolled corridor  because of the tolls they pay or the increase in travel time they incur  by choosing an alternate route. Furthermore, drivers who choose to  avoid the tolls and take an alternate route may contribute to  congestion on the alternate route. Such diversion of traffic from tolled  routes within a corridor can reduce the performance of the alternate  untolled routes and negatively affect surrounding neighborhoods.  Issues of equity are further complicated if this traffic is diverted  through low-income and minority communities.
The transportation economics literature also suggests that the equity  impacts of congestion pricing be assessed in comparison to  alternatives—namely the predominant sources of funding roadways, such  as motor fuel and sales taxes. Comparing these sources could address  whether those who benefit from a project, such as a new lane, pay for  those benefits; for example, is the lane paid for by users of the facility or  by persons who may not use or benefit from the lane? According to the  Transportation Research Board, it may be the case that tolling and pricing  provide a more equitable means of funding roadways than these other  alternatives. We have reported that tolling is consistent with the “user  pay” principle because tolling a particular road and using the tolls  collected to build and maintain that road more closely link the costs with  the distribution of the benefits that users derive from it.
As a general rule, charging tolls on highways constructed with federal  funds is prohibited. However, Congress has enacted several exceptions  that authorize DOT to permit tolling in certain instances.
section_title: DOT Helps Facilitate Congestion Pricing through Project Approvals and Funding for Implementation, Monitoring, and Evaluation
paragraphs: DOT approves all congestion pricing projects on any roadway that  receives federal funds. DOT approval grants the project sponsor  permission to have congestion pricing on newly constructed roadwaysand lanes and converted HOV lanes through three programs. DOT also  approves design exceptions and environmental reviews that allow for  pricing on federally funded roads. DOT awarded funding to study,  implement, and evaluate congestion pricing projects and DOT programs  require monitoring and evaluation of pricing projects, although the level of  detail varies by program. When applicable, DOT oversees projects and  certifies that program performance standards have been met.
subsections: section_title: DOT Approves Tolling, Project Design Exceptions, and Environmental Reviews on Federally Funded Highways
paragraphs: Congress has authorized DOT to approve tolling, which can include  congestion pricing, through three programs. Table 1 provides a summary  of the three DOT congestion pricing programs and number of operational  or under construction congestion pricing projects authorized under each  program.
DOT has also approved design exceptions for certain highway projects that  include congestion pricing. DOT has approved exceptions to highway  standards to allow for changes to highways to increase capacity within the  existing right of way or “footprint.” The Florida Department of  Transportation received design exceptions for I-95 in Miami to convert parts  of the median and shoulder lanes and to narrow other lanes from the  standard 12 feet to 11 feet to make two HOT lanes in each direction. The  Minnesota Department of Transportation has received design exceptions to  convert shoulder lanes for electronic tolling and bus service during peak  periods on I-35W in Minneapolis. This lane also serves as a HOT lane for  solo drivers who pay a toll during the same period. The Minnesota  Department of Transportation’s design exceptions included changes in lane  width and shoulder width as well as advisory speed limits.
In accordance with the National Environmental Policy Act of 1969, as  amended (NEPA) and its implementing regulations as well as Executive  Order 12898, DOT reviews projects to assess their anticipated  environmental and socioeconomic impacts and to determine their need for  any additional reviews. Projects that are deemed to have significant  environmental impacts must prepare an Environmental Impact Statement.  When it is unclear whether or not a significant environmental impact will  occur as a result of the project’s impacts, an Environmental Assessment  must be prepared. Environmental impacts may include effects on air, noise,  water quality, wildlife, and wetlands. Additionally, projects may be required to  undergo an environmental justice assessment to determine its impacts on  low-income and minority populations. Projects that a federal agency has  previously determined to have no significant environmental impacts may  receive a categorical exclusion, meaning that they do not have to complete  an Environmental Impact Statement or Environmental Assessment to comply  with NEPA. DOT has approved categorical exclusions for congestion  pricing projects that do not lead directly to construction and changes in the  facility’s “footprint” in accordance with NEPA implementing regulations, along  with projects that include new electronics and communications systems for  tolling. According to project sponsors that we interviewed, pricing projects  that have not changed a facility’s “footprint,” such as HOV to HOT lane  conversions or peak-period pricing on already tolled highways, bridges, and  tunnels, have received categorical exclusions. In addition, projects that have  narrowed the width of lanes and converted medians and shoulder lanes that  have not involved changing the “footprint” of the highway have received  categorical exclusions.
section_title: DOT Has Provided Funds for Studies, Implementation, and Evaluations of Congestion Pricing Projects
paragraphs: DOT has provided funds to promote congestion pricing through several  programs that involve tolling—the Urban Partnership Agreement (UPA)  and Congestion Reduction Demonstration (CRD) programs and the Value  Pricing Pilot Program (VPPP). UPA and CRD, the largest programs that  involve tolling, advance congestion pricing through funding awards from  10 separate grant programs. As part of one-time initiatives, the UPA and  CRD participants—Seattle, Washington; San Francisco, California;  Minneapolis-St. Paul, Minnesota; Miami-Ft. Lauderdale, Florida; Los  Angeles, California; and Atlanta, Georgia—were provided approximately  $800 million through grant programs to implement tolling as well as  transit, technology, and telecommunications strategies to reduce  congestion. Funds have been used to build new HOT lanes, convert HOV  lanes to HOT lanes, establish electronic tolling systems, and purchase  buses for express bus service on HOT lanes.
In addition, DOT has provided about $100 million in grants for studies,  implementation, and some evaluations of congestion pricing projects  through VPPP since it was established in fiscal year 1998. Nearly all  congestion pricing projects in operation have received VPPP funds at one  time or another for these purposes. About a third of total VPPP grants  were awarded to fund three of the six UPA participants—Seattle in fiscal  year 2007 and Minnesota and San Francisco in fiscal year 2008. that, Congress authorized $11 million in fiscal year 2005 and $12 million  per year for fiscal years 2006 through 2009 for projects that involve  highway pricing, of which $3 million per year was set aside for nontolling  projects, such as parking and car sharing projects. See appendix III for a  list of VPPP grants and activities from fiscal years 1999 through 2010.
San Francisco’s SFPark uses congestion pricing by adjusting parking meter and garage  prices up or down based on the demand for parking. Drivers can receive real-time  information about where parking is available and at which price using personal mobile  devices such as iPhones. This “demand-responsive” pricing encourages drivers to park in  underused areas and garages, reducing demand for parking in overused areas.
VPPP funds have been used to:
Study the potential of pricing in a corridor or region or the  feasibility of a particular pricing project. Studies have  examined the benefits of implementing variable pricing on an  already tolled facility such as the Florida Turnpike in Miami-Dade  County and the Pennsylvania Turnpike near Pittsburgh and  Philadelphia. VPPP-funded studies have also examined the  feasibility of extending HOT Lanes such as I-15 in San Diego,  California.
Implement elements of projects. Lee County, Florida, used a  grant to purchase transponder readers for electronic tolling on two  of its bridges. The Washington State Department of  Transportation used VPPP funds to install electronic tolling  technology on the SR 520 bridge that determine changes in tolls  based on congestion.
Evaluate specific projects. Evaluations studied the results and  challenges of implementing pricing projects including SR 91 in  Orange County, California; I-15 in San Diego; California; I-394 in  Minneapolis, Minnesota; and I-10 and U.S. 290 in Houston,  Texas.
In addition to the funding provided through VPPP, federal funding is  available for congestion pricing projects through other programs. For  example, federal credit assistance available under the Transportation  Infrastructure Finance and Innovation Act program has been used to help  finance construction of HOT lanes for 7 projects including those on I-495  in Virginia, I-635/I-35E in Texas, and I-595 in Florida. In addition, states  receive nearly $40 billion a year in federal funding for highways through a  series of grant programs collectively known as the Federal-Aid Highway  Program. These grant programs have also been used to help finance the  construction of congestion pricing projects.
section_title: DOT Requires Performance Monitoring for All Its Toll Programs and Compliance with Performance Standard for Its HOV Facilities Program
paragraphs: The HOV Facilities program requires project sponsors to annually monitor  and report HOT lane traffic speeds and is the only DOT tolling program  that requires project sponsors to meet an annual performance standard.  In the case of an HOV facility with a speed limit greater than 50 miles per  hour, vehicles must be able to travel at least 45 miles per hour 90 percent  of the time during weekday morning and evening peak hours over a 180- day period. If this standard is not met, the road operator must make  changes to bring the facility back into compliance. Such changes could  include raising tolls on paying cars or changing carpooling requirements  to achieve the standard. DOT established this speed requirement  because HOV lanes, by law, are transit “fixed guideway” facilities that  encourage transit use and thus traffic must maintain speeds compatible  with express bus service. Nearly all HOV to HOT lane conversions in  operation have been authorized under either the HOV Facilities program  or VPPP (and its predecessor, the Congestion Pricing Pilot Program).  Projects that were authorized under HOV Facilities have this performance  requirement. DOT monitors the reported performance of HOT lanes  authorized under the HOV Facilities program. According to DOT officials,  there has not been a case in which a HOT lane has not met the standard.
Pub. L. No. 109-59, § 1604(b)(7)(A). construction and construction has not begun on the fifth, no performance  reporting for completed ELD projects currently exists.
DOT also requires project sponsors that receive VPPP funds to monitor  and evaluate the performance of their projects so that the agency can  report results biannually to Congress as required by statute. Project  sponsors report five categories of effects—(1) driver behavior, traffic  volumes, and travel speeds; (2) transit ridership; (3) air quality; (4) equity  for low-income individuals; and (5) availability of funds for transportation  programs. As with the ELD program, projects that receive VPPP grants  are not required to meet specific performance standards.
Under the UPA and CRD programs, DOT has provided funds to the  Battelle Memorial Institute to conduct an independent national evaluation  of the effectiveness of the program’s four congestion reduction  strategies—tolling, transit, technology, and telecommuting. Projects will  be assessed individually and results compared across all projects in the  six metropolitan areas according to specific metrics. These metrics  include reductions in congestion delay and duration; increases in the  number of cars and people in cars (i.e., vehicle and passenger  throughput), and shifts to travel during off-peak times, among other  factors.
See appendix IV for list of performance and monitoring requirements for  federal programs for congestion pricing projects.
section_title: Project Evaluations Have Generally Shown Reduced Congestion, but Other Effects Have Not Been Consistently Assessed
paragraphs: Evaluations of 14 congestion pricing projects in the United States have  generally shown reduced congestion, although other results are mixed, and  not all possible relevant effects have been assessed. HOT lane projects,  which aim to improve the flow of traffic and throughput with increased  speeds and decreased travel times, have reduced congestion by  increasing vehicle throughput, and have generally shown reduced  congestion, increased speeds, and decreased travel times in the priced  and unpriced lanes. Some HOT lane projects have added new lanes and  thus, for these projects, the effects of pricing on performance have not  been distinguished from the effects of the added lane. In addition, although  the number of cars using HOT lanes has risen, there were fewer people in  the cars—a fact attributed to an increase in the share of toll-paying solo  drivers or a decrease in carpooling on HOT lanes. Peak-period pricing  projects that aim to reduce congestion by encouraging drivers to travel at  off-peak times have shifted some drivers to travel during those times. Other  effects of congestion pricing projects, such as equity income impacts, have  not always been evaluated. Evaluating these impacts is important to  address public and elected officials’ concerns about the effects of pricing  on travelers and communities. Not evaluating these effects leads to an  incomplete understanding of the full effects of pricing.
Of the project sponsors that have operational congestion pricing, 8 have a  current and completed evaluation of at least one of their projects, for a  total of 14 evaluated projects. These eight evaluations assess five HOT  lane projects and nine peak-period pricing projects, as shown in figure 2.  For a description of our objectives, scope, and methodology in analyzing  the congestion pricing projects, see appendix I.
Because of differences in project objectives and in DOT’s monitoring and  evaluation requirements, the completed evaluations vary in which aspects  of performance they report. No evaluation has assessed the performance  of congestion pricing across projects. In addition, the evaluations  represent an assessment of the results of the projects at specific points in  time. Were the evaluations on-going or repeated at different time  intervals, it is possible that the results would differ. The most common  measures used across the evaluations have been travel time and speed,  throughput, off-peak travel, transit ridership, and equity. Table 2 lists and  defines these five common performance measures and definitions used in  congestion pricing project evaluations.
Evaluations of HOT lane projects, which are designed to improve travel  time and speed, have shown improvements. Both travel time and travel  speed improved on at least some sections of all five HOT lane projects  that were evaluated. Sometimes the improved travel times in the HOT  lanes also led to improved travel times in the adjacent unpriced lanes  because solo drivers paid to switch to the HOT lanes. For example, on  SR 167 in Seattle, peak-hour travel speeds on the adjacent unpriced  lanes increased as much as 19 percent compared with travel speeds in  2007 while speeds on the HOT lanes remained about the same,  averaging the speed limit of 60 miles per hour.evaluation of I-15 in San Diego, drivers in the HOT lanes reportedly saved  up to 20 minutes more than drivers in the adjacent unpriced lanes during  the most congested times. Neither project included a new lane. Two other  HOT lane projects—on I-95 in Miami and SR 91 in Orange County — included two new lanes in each direction, which also helped improve  travel times and speed. On I-95, for example, which Florida Department  of Transportation officials identified as the most heavily congested  highway in the state before pricing began in 2008, the evaluation reported  that drivers have reportedly saved about 14 minutes in the HOT lanes  and 11 minutes in the adjacent unpriced lanes per trip. Evaluations of the  I-95 and SR 91 projects did not, however, isolate the effects of the added  lane and pricing on performance. Isolating such effects is challenging  because even if a study accounts for the increased vehicle throughput on  the new lanes, it may then understate the throughput the other lanes  could have handled if the new lanes had not been added.
Evaluations of the nine peak-period pricing projects with completed  evaluations reported no effects on travel time and speed. Two of these  evaluations—of the New Jersey Turnpike and Lee County bridges— analyzed these effects. Although travel times on the New Jersey Turnpike  improved from 2000 to 2001 when electronic tolling and peak-period  pricing were introduced at the same time, the project evaluation attributed  the improvement mostly to electronic tolling and not to pricing.
Evaluations of all five HOT lane projects reported an increase in vehicle  throughput—as measured by traffic volumes—on the HOT lanes and  sometimes on the adjacent unpriced lanes and attributed this increase to  both congestion pricing and the addition of new lanes. For example,  according to a 2006 evaluation of the I-394 project in Minneapolis, vehicle  throughput in the HOT lanes increased by 9 to 13 percent and by 5  percent in the adjacent unpriced lanes after the lanes opened. A 2000  evaluation of the SR 91 project in Orange County estimated that vehicle  throughput increased 21 percent on the entire roadway.
Four of the five HOT lane project evaluations that tracked the average  number of people in a car (known as average vehicle occupancy) showed  a decrease in the number of passengers per car. Thus, while there were  more cars using the HOT lanes, there were, on average, fewer people in  the cars, which project sponsors attributed to an increase of the share of  toll-paying solo drivers or a decrease in carpooling in the HOT lanes. In  addition, evaluations of two projects assessed passenger throughput  which takes into account the number of people riding buses as well as the  average vehicle occupancy rate to estimate the total number of people  moved through the roadway. According to the evaluations, passenger  throughput on I-15 in San Diego increased slightly between 1997 and  1998, and then decreased between 1998 and 1999, and passenger  throughput on I-95 in Miami increased 42 percent between 2008 and  2010 on the HOT lanes—a result the evaluation attributed to an increase  in toll-paying solo drivers, transit ridership, and the addition of two HOT  lanes.
Evaluations of peak-period pricing projects found no increase in  throughput due to congestion pricing. Specifically, evaluations of the New  Jersey Turnpike and Lee County bridges assessed the impact of pricing  on traffic volume and found no changes in vehicle throughput or average  vehicle occupancy due to pricing that differed from overall traffic trends.
To evaluate two of the five HOT lane projects—I-15 in San Diego and SR  91 in Orange County—project sponsors surveyed drivers to determine  whether they changed their trips to travel at off-peak times. According to  the I-15 survey results, some traffic shifted from the middle of the peak  rush hour to the “peak-shoulder” times—the times directly before and  after peak periods. However, the sponsors did not explain why this shift  occurred. Drivers surveyed for the SR 91 evaluation said that the level of  congestion affected their travel time decisions more than the presence of  the toll. Project sponsors that did not study shifts to off-peak travel times  said they did not do so because, in one case, the sponsor did not see the  HOT lanes as offering incentives that would encourage peak-period  travelers to shift their travel to off-peak periods, and, in another case, the  sponsor was not required to study shifts to off-peak travel but would  consider doing so in the future.
Sponsors of peak-period pricing projects conducted more robust studies  of off-peak travel because it was a more explicit goal of their projects.  These studies showed some success in reducing congestion during peak  times. Evaluations for two of the three peak-period pricing projects  showed that drivers chose to take trips at off-peak times on highways,  bridges, and tunnels to take advantage of discounted tolls. For example,  according to a 2005 performance evaluation of traffic on bridges and  tunnels into New York City conducted by the City University of New York  for the Port Authority of New York and New Jersey, car and truck traffic  increased in off-peak periods for most crossings. The evaluation  reported more significant improvements in the morning before the peak  periods than after the peak periods at the end of the day, which the  evaluation attributed to drivers finding it easier to arrive at work early than  to arrive at work later. According to this survey, a majority of drivers had  little flexibility to change their schedule to travel at off-peak times. For  example, truck drivers said that they could not adjust their delivery  schedules to travel at off-peak times. Furthermore, drivers said that the  toll difference of $1 was not great enough to influence them to change  their travel time. Despite this, a significant minority could alter their travel  departure times between 30 minutes and 2 hours. Thirty-five of the 505  surveyed drivers representing 7.4 percent of passenger trips said that  they changed their travel behavior as a result of the project. According to  the Port Authority, the 7.4 percent change in passenger trips to off-peak  times is significant, since small changes can have exponential effects  because of traffic queuing.
An evaluation of peak-period pricing on the New Jersey Turnpike based  on a driver survey found that work schedules or a desire to avoid traffic  created a greater incentive for determining when to travel than a slightly  lower toll for off-peak travel. Thus, it appears that drivers chose to travel  at off-peak times because of congestion and not because of modest  differences in price.
Evaluations of four of the five HOT lane projects assessed changes in  transit ridership, but results were mixed. I-95 in Miami was the only one  with demonstrated increases in transit ridership. Between 2008 and 2010,  the average weekday ridership on the I-95 express bus increased by 57  percent, from about 1,800 riders in 2008 to more than 2,800 in 2010.  About 38 percent of these riders reported in a transit rider survey that  they used to drive alone. The other three HOT lane project evaluations  found no increase in transit ridership on buses using the HOT lanes as a  result of the project. While transit ridership reportedly increased on I-15 in  San Diego, the evaluation stated that this increase was not linked to the  project. Evaluations of all three peak-period pricing projects assessed  whether drivers shifted to transit, but none found evidence of any  changes in transit ridership.
Many efforts have been made to assess the effects of congestion pricing  projects on equity, including income equity (the distribution of costs and  benefits of congestion pricing between low- and high-income drivers) and  geographic equity (the relative effects of congestion pricing on two  geographic areas, including the effects of any traffic diversion). Three of  the eight evaluations, covering one HOT lane project and three peak- period projects, attempted to assess both income and geographic equity,  and none attempted to assess other effects on equity, such as whether  members of the same group are treated differently or to what extent the  beneficiaries of a project, such as a new lane, pay for those benefits.
Evaluations for four of the five HOT lane projects attempted to assess  equity through surveys or focus groups of travelers concerning their use  of congestion pricing projects; however, different elements of equity were  evaluated. For example, three of the four HOT lane project evaluations  that assessed equity did so by considering the effects of congestion  pricing on drivers of different income levels. Results for these three  projects—SR 91 in Orange County, I-394 in Minneapolis, and SR 167 in  Seattle—indicated that drivers of all incomes used the HOT lanes, but  high-income drivers used them more often than low-income drivers.addition, evaluations for all four HOT lane projects—SR 91 in Orange  County, I-394 in Minneapolis, SR 167 in Seattle, and I-15 in San Diego— found that drivers liked having the option of using the HOT lanes and thus  were supportive of them. The fifth HOT lane project—I-95 in Miami—has  not undergone an assessment of the effect of congestion pricing on low-  In  income drivers because, according to the project sponsor, the benefits of  congestion pricing—including increased travel speeds—accrue to all  users.
Evaluations of the nine peak-period pricing projects considered different  elements of equity and found few impacts. However, all three projects  were previously tolled and toll discounts were offered for travel at off-peak  times. Thus, no tolls, including those for peak periods, were raised. The  New Jersey Turnpike Authority evaluated the income and ethnicity of  those who shifted to the off-peak times, while the Lee County Department  of Transportation assessed the age, gender, and work schedules of those  who shifted to the off-peak times. Both project sponsors also surveyed  drivers, who said they thought the off-peak discounts were equitable and  the pricing program fair. However, the sample sizes for both these  surveys were small; thus, the results may not provide reliable estimates  for the various subgroups they measured.
Evaluating geographic equity—or the effects of any traffic diverted from  HOT lanes or from peak-period priced highways, bridges and tunnels  onto unpriced lanes and roads—would provide decision makers with  information about potential negative effects, such as whether traffic on the  unpriced alternatives increased. The sponsor of one of the five HOT lanes  projects—SR 91 in Orange County—studied diversion and reported that  traffic was drawn to the roadway and its HOT lanes because the priced  lanes were new and added capacity. Sponsors of the other four HOT lane  projects did not evaluate traffic diversion for several reasons, according to  the sponsors. First, drivers can choose to drive in the unpriced lanes and  none of the projects took away an unpriced lane—only HOV lanes were  converted. Furthermore, two of the HOT lane projects added a lane to the  roadway and allowed solo drivers to use a previously underused HOV  lane. As a result, the sponsors said they expected drivers to be diverted  to the HOT lanes, not away from them. Second, even if they had  anticipated traffic diversion to alternative roads, the sponsors said they  would not have surveyed drivers or asked them to maintain travel diaries  because these methods were expensive and challenging to implement.  They added that electronic data collection methods, such as GPS  tracking in vehicles, transponder tracking, and license plate tracking, can  be expensive and raise privacy issues.
Two peak-period pricing project sponsors—the New Jersey Turnpike  Authority and the Lee County Department of Transportation—studied  traffic diversion to adjacent unpriced roads and found no evidence of  diversion. According to the studies, such diversion would not be likely for  these roadways because there are no comparable alternative routes.
Furthermore, the projects were previously tolled and congestion pricing  was implemented with off-peak discounts. As for the HOT lane projects,  traffic diversion may be less of a concern if a highway, bridge, or tunnel  was previously priced than if it was previously unpriced.
Sponsors of one HOT lane project—SR 167 in Seattle—and one peak- period pricing project—the New Jersey Turnpike—evaluated the impact of  pricing on minorities. An environmental justice assessment for SR 167  found that there would not be a disproportionate effect on minorities  because there was a small minority population in the area, the project  was limited to 9 miles southbound and 11 miles northbound, and there  were unpriced alternatives—adjacent lanes and roads—that could be  used.be no disproportionate effect on minority populations; however, as  mentioned before, the survey sample size was small and therefore its  results cannot be generalized to all users.
The 2005 New Jersey Turnpike evaluation found that there would  Evaluations of three HOT lane projects—I-15 in San Diego, SR 91 in  Orange County, and I-394 in Minneapolis—and one peak-period pricing  project—the New Jersey Turnpike—assessed environmental effects. All  four evaluations assessed the impacts of pricing on air quality, and one  HOT lane project—I-394—also assessed noise impacts. The air quality  assessments, designed to test whether air quality improved as experts said  it could with fewer cars idling in traffic, showed mixed results: minimal air  quality improvements were reported on I-15, I-394, and the New Jersey  Turnpike, but no effects on SR 91. The noise impact assessment on I-394  found that there would be no significant noise impacts resulting from  pricing.
subsections: section_title: UPA Evaluations Should Improve Understanding of the Performance and Impacts of Congestion Pricing
paragraphs: The completed performance evaluations provide some information as to  the effectiveness of congestion pricing, but the UPA and CRD evaluation  framework has the potential to provide decision makers with a more  consistent and comprehensive picture of the effects of pricing. The UPA  and CRD evaluations which began in 2009 will collect data on UPA and  CRD projects in the six metropolitan areas for 1 year before a project is  implemented and then for another year after it has been implemented to  assess its effects. The evaluation framework will provide standard  performance measures such as travel times and vehicle throughput and  help develop a more comprehensive study of congestion pricing,  including increased monitoring of passenger throughput and socio- economic information of HOT lane users. Performance measures and  detailed metrics will be used to assess individual projects and across  projects, which has not been consistently done so far. The evaluation  framework will also assess the impacts of pricing on low-income drivers  and changes in their travel time and distance traveled as a result of  pricing. Travel diary surveys will be conducted at two of the UPA sites,  which may provide some basis to study equity impacts including whether  driver behavior changes based on income, such as diverting traffic to  adjacent unpriced roads. In addition, the evaluation framework will include  surveys to assess transit ridership for all projects that have a transit  element. Despite the potential for greater understanding of the effects of  congestion pricing as part of the UPA and CRD evaluation framework,  evaluations have only been completed in one of the six metropolitan  areas—and this was for its first phase. Thus we cannot assess the  evaluation framework or surveys’ effectiveness until they are completed.  DOT expects to have all of the UPA project evaluations completed by  2014.
section_title: Greater Equity and Safety Issues Might Develop as New Projects Are Implemented
subsections: section_title: Expanded Use of Pricing Could Raise Equity Concerns
paragraphs: Income and geographic equity concerns may become more prevalent as  congestion pricing becomes more widespread. Such concerns could be  particularly relevant for HOT lane projects with a potential for large toll  increases, such as projects that must meet HOV Facilities program  performance requirements to maintain traffic speeds of 45 to 55 miles per  hour. Tolls on pricing projects in operation are relatively low, but can be as  high as a dollar per mile. Though currently capped, these tolls could be  raised if necessary to maintain the required traffic speeds. In turn, higher  toll rates could lead to more traffic diversion if drivers chose not to pay for  HOT lanes and took adjacent unpriced lanes or roads instead.
These concerns may be particularly acute in the future for projects  designed to use pricing not only to manage congestion but also to meet  toll revenue targets. SR 520 in Seattle, which began pricing in December  2011, will generate toll revenues to pay for bonds to build a replacement  bridge. All cars, including carpools, pay a toll that varies up to $5.00.  Registered vanpools, express buses, and emergency vehicles have free  use. Because this is the first project to toll a previously untolled bridge  and there are parallel alternative routes, traffic diversion may become a  concern. According to traffic models from the area’s transportation  planning council, traffic could increase on the parallel Interstate route by 5  to 8 percent and on an alternative state road by 5 percent. Geographic  equity concerns could be minimized by introducing tolling on both the  Interstate and state road because drivers on all three routes would then  pay a toll and diversion from tolled routes to untolled routes would be less  of a concern. However, according to officials in the Seattle metropolitan  area, the public and elected officials are opposed to tolling these other  routes.
Several other projects under construction involve public-private  partnerships that plan to use toll revenues to pay for construction debt,  operations, maintenance, and provide a return to private investors.  However, meeting revenue targets can be at odds with policies to  increase throughput on highways and bridges by encouraging more  people to use carpools and express bus service. According to one expert,  project sponsors seeking to maximize revenue could in theory charge a  higher toll and make more money off of fewer paying vehicles. Raising  revenue could be at odds with managing congestion (e.g., increasing  passenger throughput) if higher tolls can produce more revenue from  fewer paying vehicles. In addition, as we have previously reported, tolls  on roadways operated by private concessionaires can be expected to be  higher than on comparable facilities operated by public agencies. Three  projects—I-495 in Northern Virginia and the LBJ Express (I-635/I-35E)  and North Tarrant Express (I-820-SH 121/183) in Dallas-Ft. Worth—are  public-private partnerships in which the private operator sets the toll rate.  I-595 project in Broward County, Florida, is also a public-private  partnership, but the state department of transportation has retained the  authority to set the toll rate.
In addition, I-95 in Miami has raised its carpool occupancy requirements for free use  from two to three passengers. Thus, two-passenger carpools pay a toll to use the HOT  lanes or use the adjacent unpriced lanes. According to the Florida Department of  Transportation, it has not studied the impact of pricing on two-passenger carpools and  therefore does not know how many people have been affected. conversion of HOV lanes or the addition of new lanes.bridge in Seattle is the only previously unpriced facility to be fully priced.  According to experts, pricing existing unpriced lanes and roadways could  lead to geographic equity concerns as drivers divert to alternate routes to  avoid tolls.
While future pricing projects may raise equity concerns, these concerns  should be weighed against the potential benefits, including enhancing  economic efficiency, increasing throughput, and reducing congestion. For  example, greater use of pricing could enhance economic efficiency by  discouraging solo driving and making alternatives such as carpooling or  taking transit more appealing, thus resulting in more efficient use of existing  roadways. Such changes in drivers’ behavior could also improve  throughput and reduce congestion. In addition, as previously discussed,  the equity impacts of congestion pricing can also be assessed in  comparison to the equity concerns raised by the alternatives—namely the  prevalent sources of funding roadways such as motor fuel and sales taxes.
A number of options are also available to address equity issues. One  such option is to use a portion of toll revenues for alternative  transportation modes in the highway corridor, such as express bus  service on HOT lanes. In general, bus riders are disproportionately lower- income individuals who would benefit from both reduced congestion on  the HOT lanes and increased transit investments from toll revenues. In a  survey of Seattle residents, public support for tolling the SR 520 bridge  grew substantially if a portion of the toll revenue was dedicated to transit,  even if tolls had to be significantly higher to pay for transit service. As part  of its UPA program funding, Seattle has received grant funds for new  buses to begin service on the SR 520 bridge. Other UPA program  participants, including Minnesota and Miami, have received DOT grants  for express bus service on HOT lanes. Under the ELD program, Federal  law permits the use of excess toll revenue for eligible highway and/or  transit service; however, pricing projects generally have not had excess  revenues. Officials with the transportation planning council for the  Minneapolis-St. Paul area told us that revenues from the I-394 project  have generally not exceeded the project’s operational costs and therefore  local transit funds are being used, as they were before the project was  initiated, to provide express bus service on the HOT lanes. The San  Diego Association of Governments also has used bus fare revenue to  fund express bus service on I-15 in San Diego because the HOT lanes  have not generated enough toll revenues to pay for bus service. In  addition to the availability of revenues, the effectiveness of providing  revenues to transit to address equity also depends on the availability of  transit service and traveler commuting patterns. Transit may not be an  option for some travelers given the location of homes, jobs, and other  travel destinations.
I-25 in Denver has taken steps to address equity among passengers and  drivers on the HOT lanes by setting its peak period toll rate based on the  fare charged to express bus passengers on the HOT lanes. Thus, as the  fare for express bus passengers increases, the toll rate for drivers to use  the HOT lanes also increases.
An additional option to address equity issues would be to use toll  revenues to reimburse low-income drivers, whether by exempting them  from paying tolls or by providing them with a tax credit for the difference  between the toll and transit fares. However, such reimbursement  programs would involve complex efforts to determine and verify drivers’  low-income status. Nonetheless, some states such as California offer  discounted utility rates for eligible households and in these states,  transportation agencies have considered whether to use these preexisting  mechanisms for eligibility and enforcement to provide discounted toll  rates. However, no pricing project has used this option. Some experts  have noted that discounts on tolls for low-income drivers would  counteract the goal of reducing congestion because the discounts would  encourage continued driving. Instead, they propose charging the same  tolls to all users, but returning revenues to affected groups, such as  groups of vehicle owners or a class of residents. VPPP federal funds  were used to study the potential of providing credits for low-income  highway users in Alameda County, California but no pricing project has  used this option.
To provide insight on environmental justice issues, DOT approved two  VPPP grants for fiscal year 2010-2011 to assess the impacts of pricing on  low-income drivers. One grant, for I-30 in Dallas-Ft. Worth is to examine  environmental justice issues related to pricing I-30 through the use of  Intelligent Transportation Systems technology. According to DOT, “the  project is important because it will provide more data on environmental  justice and pricing, given that there is little experience with strategies  designed to address these issues related to the introduction of pricing.”  The other grant, for a pricing project in Hartford, Connecticut, is to study  the application of pricing and the impacts of environmental justice issues  that resulted from the original construction of a project.
section_title: Potential Safety Issues May Occur with Pricing Converted Shoulder Lanes and Narrowing Lanes
paragraphs: Many highway projects increase the capacity of a roadway by converting  shoulders or narrowing lanes which has the advantage of eliminating the  need to widen highway and acquire additional property—of particular  advantage in urban areas. Several congestion pricing projects have  employed this strategy. For example, the Minnesota Department of  Transportation has converted bus-only shoulder lanes on I-35W in  Minneapolis to serve as HOT lanes during peak periods and has  narrowed traffic lanes from 12 feet to 11 feet. In addition, as previously  noted, the Florida Department of Transportation has incorporated portions  of its medians and shoulders and narrowed traffic lanes from 12 feet to 11  feet to create two HOT lanes on I-95 in Miami. Moreover, two new  projects—Loop 1 in Austin and I-94 in Minneapolis—will create new  capacity by using shoulders and narrowing traffic lanes. The Loop 1  project will reduce shoulder width and incorporate parts of the shoulders  to create an express lane, while the I-94 project may, if implemented, use  shoulders and narrowed traffic lanes to create a HOT lane between  Minneapolis and St. Paul. According to the project sponsor, I-94 does not  have the space to build new HOT lanes if shoulders are not incorporated.
Projects that convert shoulders and narrow lanes to create new lanes,  including congestion pricing projects, raise concerns about driver safety  and highway operations that transportation planners must address.  Additional lanes on converted shoulders remove the safety refuge areas  for motorists during vehicle breakdowns and emergencies and must be  approved by DOT. According to the American Association of State  Highway Transportation Officials, highways with paved shoulders have  lower accident rates. Paved shoulders provide space to make evasive  maneuvers; accommodate driver error; and add a recovery area to regain  control of a vehicle, among other things. In addition, an analysis by the  Highway Safety Information System sponsored by DOT reported that  narrowing lanes or using shoulders to expand urban highways increased  accidents by 10 percent. With traffic moving faster in the additional (or  HOT) lane and slower in the unpriced lanes, the potential for sideswiping  and lane-changing accidents increases. Another study conducted by the  Texas Transportation Institute found that maintaining a shoulder and a  wider HOV lane than adjacent unpriced lanes can help mitigate safety  concerns.
FHWA officials in Florida suggested that some of these safety issues  could be mitigated using an incident management system, such as the  one the Florida Department of Transportation has used on I-95 since  2008. As a condition of approving several design exceptions, FHWA  required the Florida Department of Transportation to implement Intelligent  Transportation Systems to mitigate safety issues related to incorporating  a shoulder and narrowing lanes on I-95 in Miami. While using an incident  management system does not prevent incidents from occurring, cameras  can survey highways and detect incidents such as accidents, debris, and  stalled vehicles. Highway message signs then convey information to  drivers about the incidents and traffic conditions. Florida Department of  Transportation staff can summon emergency, police, and tow truck crews  to resolve problems and direct traffic. Thus, in the event of an incident on  the HOT lanes, the lanes can be closed and, because there are no  permanent barriers between the HOT lanes and the adjacent unpriced  lanes, traffic can be diverted to the adjacent unpriced lanes. In the event  of an accident in the unpriced lanes, the lanes can be closed and traffic  diverted to the HOT lanes and tolls temporarily lifted.
Since the HOT lanes on I-95 opened for traffic in December 2008,  preliminary safety data found that the number of reported incidents  involving accidents, debris, and stalled vehicles in the northbound  express lanes increased from 132 in fiscal year 2009 to 209 in fiscal year  2010. Florida Department of Transportation officials have suggested,  however, that the actual number of incidents may not have increased but  that incidents are now tracked more accurately. In addition, according to  FHWA officials in Florida, the number and severity of crashes declined  after the I-95 HOT lanes became operational. In their view, the HOT lanes  decreased congestion, and as a result, fewer rear-end crashes occurred.  Additionally, FHWA officials stated that they have not seen evidence of  more sideswiping since the traffic lanes were narrowed to form the HOT  lanes. The UPA and CRD National Evaluation will assess the safety  impacts of pricing, including the number of accidents and their severity  and any change in the perception of safety by travelers and emergency  personnel since pricing began.
section_title: Concluding Observations
paragraphs: Although traffic congestion has declined recently in many metropolitan  areas, future demand for travel during peak times is expected to increase  as the population grows and the economy recovers. Fiscal and  environmental concerns prevent building new capacity in many  metropolitan areas. Transportation decision makers have a variety of traffic  demand management tools, including road or congestion pricing, to more  efficiently operate and manage their infrastructure. Pricing has the potential  to reduce congestion by influencing drivers to carpool, use transit, or drive  at off-peak travel times. Congestion pricing has, where evaluated, helped  reduce congestion. However, it is difficult to draw overall conclusions about  the effectiveness of pricing because only half the sponsors with projects  now open to traffic have evaluated their projects. Other results, where  available, are mixed, as project sponsors have used different measures to  assess performance and little has been done to compare performance  across projects. Where congestion pricing projects have also added lanes,  the results of pricing have not been distinguished from the results of adding  capacity. Finally, congestion pricing’s impact on traveler behavior and  equity has yet to be fully explored.
Congestion pricing in the United States is in its relative infancy. With  about 400 miles of priced lanes in operation, which includes 150 miles of  the New Jersey Turnpike, pricing has not been implemented beyond a  limited number of locations. However, its popularity is growing. New  projects under construction and in planning will not only increase the  number of roadway miles that use congestion pricing, they will also  change the character of pricing in the United States, as some will be  operated privately and some will add congestion-priced tolls to previously  nontolled roadways. The changing character of congestion pricing and  the new challenges it brings make improving the understanding of  congestion pricing even more important.
While a more complete understanding of the potential benefits and effects  of congestion pricing is needed, we are not making a recommendation in  this report because the evaluations conducted through the UPA and CRD  programs are an important step to furthering understanding of the  relevant benefits and effects of pricing. These evaluations of pricing  projects address reservations we have about gaps in knowledge about  such projects—for example, these evaluations will compare results  across projects to assess the effectiveness of congestion reduction  strategies and assess several measures of equity. In addition, monitoring  and reporting on the five ELD projects could also provide better  information about the performance of pricing and its effects. However,  only one of the six UPA and CRD metropolitan sites has been evaluated  and only for its first phase and four of the five ELD projects are under  construction. As such, we cannot assess the evaluation framework or  their results until projects and their evaluations are complete.
section_title: Agency Comments
paragraphs: DOT provided technical comments, which we incorporated as  appropriate.
As agreed with your offices, unless you publicly announce the contents of  this report earlier, we plan no further distribution until 30 days from the  report date. At that time, we will send copies of this report to  congressional subcommittees with responsibilities for surface  transportation issues and the Secretary of Transportation. In addition, this  report will be available at no charge on GAO’s website at  http://www.gao.gov.
If you or your staff have any questions about this report, please contact  me at (202) 512-2834 or herrp@gao.gov. Contact points for our Offices of  Congressional Relations and Public Affairs may be found on the last page  of this report. GAO staff that made significant contributions to this report  are listed in appendix V.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: Our work was focused on the performance of congestion pricing projects  on highways, bridges and tunnels in the United States and issues  associated with developing and implementing pricing projects. We  examined (1) the federal role in supporting congestion pricing, (2) results  of congestion pricing projects in the United States, and (3) emerging  issues in congestion pricing projects. Our scope was limited to assessing  congestion pricing projects in the United States that involved passenger  vehicles. We did not review other types of congestion pricing such as  priced parking facilities. We collected information on pricing projects  directly from the 19 project sponsors of the 41 operational or under  construction congestion pricing projects and received comments and  validation of data from project sponsors.
To address the federal role in supporting congestion pricing, we reviewed  pertinent legislation and regulations; prior GAO reports and testimonies; and  relevant documents from the U.S. Department of Transportation (DOT), state  departments of transportation, and metropolitan planning organizations  (MPO). This included policy documents from the Federal Highway  Administration (FHWA) and various public presentations made by FHWA  officials. We interviewed FHWA and Federal Transit Administration (FTA)  officials, officials from state DOTs and MPOs, experts from academia and  policy institutions, the Congressional Research Service (CRS), and the  Congressional Budget Office (CBO). Our discussions with FHWA included  DOT’s programs that involve tolling—Value Pricing Pilot Program (VPPP),  High Occupancy Vehicle (HOV) Facilities, Express Lanes Demonstration,  Section 129 program, the Interstate System Reconstruction and  Rehabilitation Toll Pilot Program, and the Interstate System Construction Toll  Pilot Program. We also discussed the Urban Partnership Agreement (UPA)  and Congestion Reduction Demonstration (CRD) programs—one-time  initiatives that were established with 10 separate federal grant programs. We  discussed the eligibility and performance monitoring requirements of the  federal programs and associated projects and verified this information with  DOT documents. We also collected data of VPPP and UPA and CRD  program funding from DOT and corroborated the status of the project data in  interviews with FHWA. We analyzed the VPPP and UPA and CRD program  funding to assess how federal funds are used to support congestion pricing  projects. We interviewed sponsors of pricing projects that received federal  funds on how the funds were used and with what results. We reviewed  relevant FHWA environmental assessment manuals and interviewed FHWA  officials about the environmental review process. We also interviewed FHWA  field staff and project sponsors regarding their individual project’s  environmental review process.
To determine the results of congestion pricing projects in the United States,  we reviewed performance evaluation reports from eight project sponsors that  covered 14 of the 30 operational pricing projects. The remaining project  sponsors did not have current and completed evaluations because their  projects had opened too recently for sponsors to have evaluated them or  because projects had changed significantly in character since they were  studied and thus the original evaluations are no longer relevant. In addition,  one project evaluation did not use pre- and post-data to measure  performance and thus the impact of pricing could not be measured. Two  project sponsors (one sponsor of the SR 261, SR 241, and SR 133 in  Orange County, California and one sponsor of the SR 73 in Orange County,  California) did not perform evaluations of their peak-period priced highways.  Two project sponsors (one for I-15 in Salt Lake City, Utah, and one for I-10  and US 290 in Houston, Texas) completed performance evaluations,  however these three highways have significantly changed in character since  then and thus the original evaluations are no longer relevant. For example, I- 15 in Salt Lake City currently uses electronic tolling with dynamic pricing  whereas when the project was evaluated a monthly decal with a static toll  was used. I-10 was evaluated as one HOT lane with free access of carpools  of 3 passengers but is now 2 HOT lanes with free access for carpools of 2  passengers. In addition, although US 290 was assessed in the I-10  evaluation, no pre- and post-data were used to measure the impact of pricing  on performance. The project sponsor of I-25 in Denver, Colorado reported on  monthly counts of traffic volumes and other measures but did not do so  before and after pricing was introduced; therefore, we were unable to use the  data to compare with other projects. Three project sponsors (I-680 in  Alameda County, California; the San Francisco-Oakland Bay Bridge in  California; and MD-200 in Montgomery County, Maryland) implemented  projects recently and have not had adequate time to evaluate the projects.  Three other projects—I-35 W in Minneapolis, Minnesota, which has the  same project sponsor as I-394; SR 520 in Seattle, Washington, which has  the same project sponsor as SR 167; and I-85 in Atlanta, Georgia—became  operational recently and have also not been evaluated. I-35W, SR 520, and  I-85 will be assessed as part of the UPA evaluations.
The eight project sponsors with current and completed evaluations we  reviewed were I-95 in Miami, Florida; I-15 in San Diego, California; SR 91  in Orange County, California; SR 167 in Seattle, Washington; I-394 in  Minneapolis, Minnesota; the New Jersey Turnpike, New Jersey; two  bridges in Lee County, Florida; and four bridges and two tunnels  managed by the Port Authority of New York and New Jersey, New York.  For each, we assessed the studies’ methodology to determine whether or  not the data reported was valid and sufficient for our analysis. However,  we did not conduct a thorough assessment of the quality of the  evaluations’ methods as our objective was to assess the projects’  performance results where available. Once we determined which data  was sufficiently reliable for our uses, we summarized the results reported  in each performance evaluation for each project. The eight performance  evaluations assessed various performance measures such as traffic  speed, travel time, throughput, and transit ridership. The performance  measures we focused our analysis on were: travel time and speed,  throughput, off-peak travel, transit ridership, and equity. As a basis for  assessing what performance measures we should review, we used a list  of performance measures, some of which are outlined in the DOT’s UPA  and CRD National Evaluation Framework. We chose these measurement  areas because they were the most commonly reported in the evaluations  and because they are the most commonly required measures for projects  with federal monitoring requirements. We corroborated our choice of  measures with FHWA and the Battelle Memorial Institute which is  conducting the UPA evaluations using similar measures. We then  compared the projects by qualitatively assessing the results for the five  performance measures listed above and counting how many of the  projects reported positive or negative results in each performance  measurement category. We could not quantitatively compare results  across projects because they did not use the same metrics and thus were  assessed and reported differently according to project sponsor preference  and resources. Project evaluations covered specific time periods and thus  performance results are only for those time periods. Projects’  performance results may have changed since evaluations were  completed.
We discussed with Battelle Memorial Institute, Texas Transportation  Institute, and the Volpe National Transportation Systems Center the UPA  and CRD evaluation framework including its performance measures and  metrics as well as challenges of conducting an evaluation across multiple  projects.
We also conducted site visits for the SR 167 and SR 520 projects in  Seattle, Washington; I-95 project in Miami, Florida; and I-394 and I-35W  in Minneapolis-St. Paul, Minnesota. We selected our site visits based on  a judgmental sample of projects with completed evaluations; these sites  included both HOT lanes and peak-period priced projects in different  geographical areas of the United States. For each site visit, we met with  relevant officials from state DOT, officials from the FHWA division office,  project sponsors, and officials from local agencies such as the MPO and  transit agencies. Discussion with project sponsors included clarifying the  goal of the pricing projects and evaluations of the project performance. In  addition to conducting interviews, we collected relevant documents,  including environmental analyses, performance evaluations, and traveler  surveys, and analyzed these documents as necessary. Where  appropriate, we corroborated the interviews with documents obtained  from project sponsors and FHWA.
To identify the emerging issues in congestion pricing projects, we  reviewed literature on congestion pricing, equity, environmental justice,  traffic diversion, safety and other topics related to the benefits, costs, and  trade-offs associated with congestion pricing. We reviewed prior GAO  reports and analyses and reports from the FHWA, CRS, CBO, and  industry experts and organizations that have evaluated the impacts of  congestion pricing projects. We discussed our review of the reports with  FHWA and FTA officials, officials from state DOTs and MPOs, and  transportation experts from academia and think-tanks. We identified and  interviewed experts with published work on congestion pricing and its  impacts. Discussions with officials and experts included the costs and  benefits of congestion pricing projects, trends in pricing designs and  implementation, and methods to mitigate negative impacts. We also  provided a copy of the draft report to a group of experts for an  independent review. We selected these experts because they have  published numerous studies analyzing the benefits and challenges of  congestion pricing and its effects that are prominent in the transportation  literature, and come from a cross section of institutions including  academia, research organizations, and the private sector. We considered  and incorporated their comments into the final report as appropriate.
Group of Experts that Reviewed Draft Congestion Pricing Report  Tod Litman, Researcher, Victoria Transport Policy Institute  Lee Munnich, Professor, Senior Fellow and Director, State and Local  Policy Program, Hubert H. Humphrey School of Public Affairs,  University of Minnesota  Robert Poole, Jr., Director of Transportation Policy, Reason Foundation  Joseph L. Schofer, Professor, Northwestern University  Brian Taylor, Professor of Urban Planning/Director, Institute of  Transportation Studies, Luskin School of Public Affairs, UCLA   David Ungemah, Senior Planning Manager, Parsons Brinckeroff  Martin Wachs, Senior Principal Researcher, RAND Corporation  We conducted this performance audit from October 2010 to January 2012  in accordance with generally accepted government auditing standards.  Those standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
section_title: Appendix II: Congestion Pricing Projects Open to Traffic in the United States, 2011
paragraphs: Date pricing  operational  December  1995  16- miles (4-mile  extension under  construction)
Salt Lake City, Utah  40 miles (11-mile  extension under  construction)
Dynamic pricing  $0.50-$9.00  7 miles (15-mile  extension under  construction)
Dynamic pricing  $0.30-$1.75  Dynamic pricing  $1.55-  $13.95  7 miles (in operation,  11 are under  construction)
Variable pricing  $0-$5.00  The New Jersey Turnpike discontinued off-peak discounts to out-of-state vehicles as of July 2011.  As of September 2011, 1 mile of MD 200 extension is under procurement.
section_title: Appendix III: DOT’s Value Pricing Pilot Program Grants, Fiscal Years 1999 through 2010
subsections: section_title: Fiscal year 1999
section_title: Fiscal year
section_title: Fiscal year
section_title: Fiscal year
section_title: Fiscal year
section_title: Fiscal year
paragraphs: Project  Express Lanes System  Concept Study  Strategies to Manage  Traffic and Parking   Strategies to Manage On- Street Parking and  Reduce Congestion From  Circling Vehicles.
section_title: Total awarded for Fiscal years 1999-2010
paragraphs: Project  Evaluate the application  of cordon/area pricing  within major activity  centers in the downtown  Los Angeles core and  build out a network of  HOT lanes  Study the application of  pricing on the I-84  Viaduct, Hartford, CT  including assessing the  impacts of environmental  justice issues that  resulted from the original  construction of the  viaduct  Study the application of  full facility pricing to the I- 95 Corridor from New  York to New Haven, CT  and identify how toll  revenues would be  applied to provide strong  support for transit  Evaluate a two-tiered  pricing on an existing toll  facility and develop  performance measures to  track the changes in  congestion, air quality,  safety, livability and other  factors that would result.
section_title: Fiscal year
paragraphs: Project  Study will look at a transit  credit program designed  to provide occasional free  use of the HOT lane for  regular transit users when  they need to drive, and a  parking pricing program  at a park and ride lot with  free parking and shuttle  services added from a  more distant lot.
Influencing Travel  Behavior and Considering  Environmental Justice.  Would examine important  environmental justice  issues related to pricing I- 30, through the use of  innovative Intelligent  Transportation Systems  (ITS) technology. The  project is important  because it will provide  more data on  environmental justice and  pricing, given that there is  little experience with  strategies designed to  address environmental  justice issues related to  the introduction of pricing.  This project was selected  because it met the  statutory eligibility criteria  and was highly qualified  for the above stated  reasons. Therefore, this  project meets the  evaluation criteria for  innovation, equity, and  congestion reduction.
section_title: Fiscal year
paragraphs: Project  183A Turnpike Pilot  Downstream Impacts.  Pilot implements a peak  period toll in conjunction  with dynamic ridesharing  on an existing congested  toll road. Would explore  applying dynamic  ridesharing as an equity  mitigation strategy. An  actual field trial is  included as part of  project. The road opens  in 2012. The local  agencies are contributing  their own funds to support  the project. Therefore,  this project meets the  evaluation criteria for  innovation, livability,  sustainability, equity,  congestion reduction,  safety and state of good  repair.
section_title: Total approved for funding for Fiscal year 2010-2011 Total awarded and approved for Fiscal years 1999-2011
paragraphs: Fiscal year 2008-2009 grants were part of the one-time Urban Partnership Agreement initiative.
section_title: Appendix IV: Performance and Monitoring Requirements for Federal Programs for Congestion Pricing Projects
subsections: section_title: Federal program Performance measure Express Lanes Demonstration
paragraphs: Performance metric
Report percentage of time facility is operating at a  minimum average speed of 50 mph broken down by daily  averages a.m. peak, off-peak, and p.m. peak hours.
Performance  and monitoring  requirement  Annual reporting  to U.S. DOT  required.
Changes in mode  split/ridership/vehicle  occupancies of priced  versus general purpose  (or adjacent free) lanes  on lane availability for the managed lanes during this time,  including the length of time each such lane was  unavailable.  Report number of declared High Occupancy Vehicles (HOV)  for the year and differences from the previous year (on a total  and percentage-change basis) broken into daily averages by  a.m. peak and p.m. peak for the managed lanes.
Report number of buses (i.e., registered non-revenue  accounts) for the year and differences from the previous  year on a total and percentage-change basis) broken into  daily averages by a.m. peak, off-peak, and p.m. peak for  the managed lanes.
Report average toll charged for the year and differences  from the previous year (on a total and percentage-change  basis), broken into daily averages, by a.m. peak, off-peak,  and p.m. peak for managed lanes.
section_title: Federal program Performance measure
paragraphs: Change in criteria  pollutant emissions at the  regional level  (particle pollution, ground-level ozone, carbon monoxide,  sulfur oxides, nitrogen oxides and lead) during the current  year and differences from the previous year (on a total and  percentage-change basis) utilizing reasonably available  and reliable air quality reporting tolls and mechanisms.
Traffic speed on priced  lane to maintain express  bus service
Report a minimum average operating speed of 45 mph on  the HOV lanes with a speed limit of over 50 mph or not  more than 10 mph below the speed limit for HOV lanes  with a speed limit less than 50 mph. This speed must be  maintained for 90 percent of the time over 180 days during  morning or evening weekday peak.
Annual  certification  required by U.S.  DOT. If  performance  standards not  met, actions must  be taken to  comply.
Performance  and monitoring  requirement  No certification  required by U.S.  DOT as no  specific  performance  standards must  be met. However,  participants are  required to report  on “value pricing”  elements up to 10  years.
Multi-year  project-specific  and national  evaluations which  U.S. DOT is  overseeing.
Percent change in route/corridor travel time by time of day  Percent change in the travel time index for comparisons  across sites (having corridors of differing lengths)  Percent change in number of hours of the day with  congested conditions and the number of congested travel  links per day  Percent change in average travel speeds by hour of the  day  Percent change in travel time reliability and planning time  index  Percent change in vehicle and person trips by time of day  and person and vehicle throughput
Change in traveler perceptions about congestion after  deployment of strategies  Level of service in tolled lanes  Travel-time reliability in tolled lanes  Average occupants per vehicle of tolled lanes versus  general purpose lanes
Use of tolling options  Traffic density in tolled lanes  Travel-time reliability (seasonally controlled)
Days exceeding reliability and performance thresholds  End-to-end travel time  Service reliability
User ratings of service performance
Corridor ridership
Corridor mode split (%)
section_title: Federal program Performance measure Equity Analysis
paragraphs: Socio-economic and geographic distribution of benefits  including: tolls paid and adaptation costs; change in travel  time and distance by group; total transportation cost;  environmental impacts  Public perception of the individualized equity impacts of  pricing  Spatial distribution of revenue reinvestment
Reduction in criteria pollutants
Reduction in noise
Reduction in vehicle miles traveled
Qualitative assessment of perceived benefits of the
Reductions in estimated fuel use
Use and impact of alternative fuel vehicles for transit  improvements  Percentage change in crash rate by type and severity  Percentage change in time to clear accidents
Change in the perception of safety by service patrol  operators, state patrol officers, medical first responders,  and bus operators
Change in the perception of safety by travelers  This is a sample of UPA and CRD performance analyses that include measures and metrics related  to the effects of congestion pricing. Other UPA and CRD analyses will look at telecommuting/travel  demand management and technology as well as impacts on businesses, goods movement, and  nontechnical success factors.
section_title: Appendix V: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the contact named above, Steve Cohen (Assistant Director),  Maureen Luna-Long, Sarah Jones, Thanh Lu, Michael Kendix, Sara Ann  Moessbauer, James Wozny, Elizabeth Eisenstadt, Crystal Wesco, and  Josh Ormond made key contributions to this report.