Congestion Pricing Principles Eno Center for Transportation


There is no silver bullet to fix the woes of urban mobility and access, but congestion pricing is a proven, viable, and effective tool. Charging a fee for the parts of the roadway network used the most at the busiest times of day reduces demand. The charges incentivize travelers to switch to other modes of transportation, seek alternative routes, or travel at other times. The charges can help to reduce negative effects of traffic such as air pollution, carbon emissions, road damage, and traffic crashes.

Though revenue generation has not been the primary objective of most congestion pricing programs, congestion pricing can yield revenues for investments in other modes and other community priorities. When based on thoughtful data and analysis, programs can help address systemic inequities.

This report seeks to accelerate the development of congestion pricing programs in the U.S. that advance sustainability and equity goals. The report is intended for elected officials, civic leaders, advocates, and agency professionals in cities and metropolitan regions. The principles outlined in this report illustrate key concepts, discuss challenges, and share examples and emerging best practices.

This report does not replicate the extensive literature and analysis that already exist. Rather, it addresses the most significant barriers to congestion pricing today: the political, institutional, and communication hurdles. While congestion pricing can benefit from sophisticated technology, the primary impediments are not technical. Congestion pricing strategies require bold leadership and vision and these principles are intended to outline an approach for getting there.

This report does not delve into specifics about implementation but is intended to inform three stages in the policy development process. One is the idea phase when the initial concept is conceived in order to address a specific problem or opportunity. Another is the planning phase where more specific details are formulated, such as how revenue would be spent. The other is the proposal phase where the final strategy is developed. These stages are not necessarily linear, however, and the principles overlap and relate to one another and inform more than one phase.

The development of the principles was informed by interviews with dozens of experts and stakeholders as well as review of literature and research. The principles also benefited from a study tour of congestion pricing programs in London and Stockholm and discussions with officials in those cities.


COVID-19 Pandemic Context

The COVID-19 pandemic upended transportation in cities and metropolitan areas in the United States and around the world. While congestion has all but disappeared, the reasons for pursuing congestion pricing will not disappear once the crisis abates. Cleaner air, better access, and a more efficient transportation network will remain top priorities in metropolitan areas.

Pursuing these goals may become even more important, as it will certainly take time for transit agencies to rebound to pre-outbreak service levels after losing considerable passenger fare and sales tax revenues due to the crisis. A post-outbreak world may see increased traffic congestion if previous transit customers become frustrated with service that is slow to return or fearful of contact with other passengers and turn to private automobiles instead. In light of this, COVID-19 should strengthen reasons for pursuing congestion pricing.


About Congestion Pricing

Congestion pricing takes several forms but is usually deployed in two main ways. Cordon (or area-wide) congestion pricing charges a fee for any vehicle that enters a defined geographic area, usually a city center, during peak hours. Dense city centers work most efficiently when public road space is allocated in a manner that moves the most people safely and efficiently. These effects are evident in Singapore, Stockholm, Milan, and London, which all adopted cordon pricing schemes. No U.S. cities have yet adopted cordon congestion pricing, although New York City is preparing to initiate one in 2021.

The other common form of congestion pricing is fees or tolls on discrete corridors or on parts of roads. In the case of high-occupancy toll lanes, motorists are charged if the number of passengers in a vehicle is below a threshold, usually two or three people. Such fees are in place today in U.S. cities including San Diego, Denver, and Houston. They mainly manage congestion on the lanes themselves, rather than on the broader transportation network. However, a new project in northern Virginia charges solo drivers to use the express lanes, with prices varying based on demand. The project provides significant resources to directly support improved public transit and non-motorized transportation projects.

The international examples described throughout this paper, in particular London, Stockholm, Milan, and Gothenburg, provide examples of how congestion charging was introduced as a means to reduce traffic in the city core. The programs in these cities also saw related benefits such as emissions reductions, fewer crashes, and better access to public services, jobs, and schools.

There is no single path to success. London's congestion pricing plan needed the unwavering support of the new mayor in order to keep it from unraveling before it even began. Stockholm benefitted from a unique governing coalition in the national legislature, then had to survive a public referendum. Governance and institutional structures vary between Europe and the United States, but congestion pricing is a major political lift in both


About Building Equitable Systems

While congestion pricing is strongly supported by transportation practitioners and economists, the concept is often met with skepticism by the general public and elected officials. The primary worries are that the charges constitute another tax on drivers, and that it will be unfair to low income populations.

The issues of equity are complex. Congestion pricing is a regressive fee, as are most other transportation charges, including gas taxes, sales taxes, and parking fees. Revenues can be used to improve transit services, which are disproportionately used by lower-income populations. However, in many U.S. cities, rising housing costs have pushed low income households farther from city centers, making transit a less viable option. Discounts can be strategically deployed to minimize impacts on communities of concern.

While congestion pricing programs can be carefully crafted to minimize impacts and bring benefits to communities, the long-standing systemic inequities in our transportation system are pervasive and remedying them requires a much more comprehensive approach.


Principle 1: Situate the policy within a clear vision and purpose.

A bold vision and rationale for addressing traffic congestion should be defined prior to pursuing congestion pricing. Clear and compelling goals with broad buy-in will build a base of support and guide discussion on trade-offs. Stakeholders will be more engaged if they know that a pricing strategy addresses locally-specific problems. The vision should transcend transportation to emphasize social, environmental, and economic outcomes by addressing a crisis or embracing an opportunity.


Principle 2: Ensure a rational nexus between revenue and spending.

Local officials may be tempted to consider congestion pricing as a way to address general revenue shortfalls. But successfully introducing a program will require a specific and direct connection between how the revenue is raised and how it is spent. Managing transportation demand and using revenue to improve multimodal transportation can boost public support. Deciding how to spend revenue should happen early in the planning, though revenue allocation should adapt to changing needs and condition


Principle 3: Improve mobility options to provide choices.

Transportation options provide alternatives to paying the congestion charge for those who want to avoid it. Revenue can be used to improve transit service as well as bicycle and pedestrian connections so commuters can easily choose something other than a single occupancy vehicle trip. Robust transit service with capacity for more riders should be in place when a congestion pricing program is rolled out.


Principle 4: Create fair programs.

Equity should be at the heart of the process of developing congestion pricing strategies and of the policy itself. Stakeholders from diverse perspectives must be brought on during the initial stages of planning. Careful and thoughtful data-driven analysis can help to identify if vulnerable populations will be disproportionately affected by congestion pricing and should ground discussions on addressing those concerns.


Principle 5: Build strong cross-sector partnerships.

Broad civic, corporate, and political support is essential to advancing congestion pricing programs, especially since various levels of government have authority over pricing proposals. Elected officials will need strong backing in order to lead on the issue. Robust community outreach and coalition building will help to normalize the concept while building the necessary support. Both agency-initiated processes and organizing by non-profits and other community groups have roles to play.


Principle 6: Communicate transparently and strategically.

Communicating congestion pricing requires clear, concise messaging to indicate its potential and counterbalance what is complex and unfamiliar. Messaging should factor in the vast array of traveler and stakeholder needs and perspectives. Outreach must begin before the concept is unveiled to the public and continue through implementation. Effective communication will both generate support for and provide details of the program.


Principle 7: Build a strong foundation first.

Congestion pricing requires a certain set of circumstances, preparation, and pre-conditions before it becomes an appropriate approach. Any city can start to lay the groundwork for considering pricing by gathering stakeholders to develop a deeper understanding of the problems to be addressed. Dynamic charges for parking and curbside uses and pilot projects can help lay a foundation for congestion pricing discussions.


Principle 8: Commit to transparency with performance targets.

Performance monitoring will measure progress in meeting policy goals and can indicate when policy changes are needed. Full transparency of information about intended outcomes facilitates engagement and support from the public and key stakeholders. Transparent reporting on the intended purpose of a charge, the effects of the charge, and strategies to improve or change the program can help to build trust in the agencies that will execute the program.


Principle 9: Limit exemptions to essential services.

There are good public policy reasons to exempt emergency vehicles from paying a congestion charge. However, exemptions that go beyond essential services may counteract the program’s effectiveness at reducing congestion. Discounts for special categories of drivers—like electric vehicle owners—may be considered as a potential means to mitigate undue burden, but only if these discounts are accompanied by sunset clauses. Robust technical analysis should accompany any consideration of exemptions.


Principle 10: Be nimble.

The technology and policy landscapes are likely to change over the course of time needed to design and implement a region's congestion pricing program. Program designers can still work within existing parameters to design an effective program while embracing a nimble approach that allows decision makers to adapt the system to changing conditions. Decision makers should understand the problems they are trying to solve before embracing a specific technology, fee structure, or policy approach.


Visit our website to read the full research report and references.


Created with images by Nabeel Syed - "Rows of car headlights" • Saketh Garuda - "Mighty Golden Gate!" • Alexander Popov - "untitled image" • Julie Tupas - "Traffic jam" • Dan Gold - "In the morning traffic"