The Heritage Foundation

Executive Summary #1721 on Smart Growth

January 27, 2004

January 27, 2004 | Executive Summary on Smart Growth

Executive Summary: The Contribution of Highways and Transit to Congestion Relief: A Realistic View

The Texas Transportation Institute (TTI) released The 2003 Annual Urban Mobility Report in September 2003, but in contrast to past years, when the report's financial backers and sponsors were largely limited to government transportation departments, this year's report received funding from, and was co-sponsored by, the American Public Transportation Association and the American Road and Transportation Builders Association.

The American Public Transportation Association, the trade association and lobbyist for government-subsidized public transit systems, was quick to claim in its press release accompanying the report's release that the findings prove that "more public transportation is needed to relieve traffic congestion." Other transit advocacy groups echoed this view. According to Paul Farmer, head of the American Planning Association, "The report found public transportation is the most effective solution for reducing delays." Similar claims by transit and smart growth advocates appeared in newspapers and newsletters throughout the country.

The Unanswered Question

The only problem is that these statements are without any foundation: The Urban Mobility Report says absolutely nothing about the effects of more public transportation on congestion.

What the report does say is that congestion would significantly increase if existing public transit systems disappeared and all transit riders immediately started driving cars. Inasmuch as no one has proposed that existing transit systems be eliminated, this conclusion, whether right or wrong, has no practical value to the current debate over how to relieve worsening traffic congestion.

Moreover, TTI's answer to this esoteric transit question may not be completely accurate. For example, TTI assumes that if transit were eliminated, all transit riders would drive cars to work, which is an improbable outcome because many transit users ride transit because they cannot drive to work.

Even allowing for the irrelevance and flawed assumptions of the question, when calculating the congestion cost of eliminating transit, the report also inappropriately includes the delay suffered by transit riders if they all drove, even though most would save time by driving.

For example, if a particular trip takes 60 minutes by transit or 30 minutes by automobile in uncongested traffic, but 40 minutes by car in congestion, the TTI study counts the extra 10 minutes in congestion as a cost of eliminating transit even though the ex-transit rider is saving 20 minutes by driving instead of using transit.

Does More Transit Really
Relieve Congestion?

In contrast to TTI's contrived policy question, this paper asks the much more relevant question: Would increasing transit's share of travel by some significant amount (e.g., 50 percent) significantly relieve congestion?

Today, such an increase in market share would require at least tripling transit spending, from less than $35 billion to more than $110 billion per year. Yet, as this paper shows, such an improbable increase in market share would save the average peak-period commuter only 22 seconds each way (44 seconds per day) in lessened traffic. Moreover, the normal growth in traffic in most urban areas would offset that saved 22 seconds in a few months.

Despite the media's focus on the transit industry's misrepresentations, overall, the Texas Transportation Institute's mobility report points the way toward congestion solutions that are far more cost-effective than improving transit. These include freeway ramp metering, traffic signal coordination, and "incident management" (quickly clearing stalled and crashed vehicles from highways). Another effective tool is turning high-occupancy vehicle (HOV) lanes into high-occupancy/toll (HOT) lanes, which would allow low-occupancy vehicles to use those lanes by paying a toll.

Except in rare circumstances, transit has little chance of reducing congestion in U.S. urban areas. Attempts to spend large sums of money to get a few automobile drivers out of their cars risk losing sight of transit's main mission, which is to provide mobility for people who cannot drive. Genuine transit advocates would focus on that mission, while those concerned about congestion should find new tools, such as congestion tolls, that would both reduce congestion and fund needed improvements in the highway system.

Wendell Cox, Principal of the Wendell Cox Consultancy in metropolitan St. Louis, is a Visiting Fellow at The Heritage Foundation and a visiting professor at the Conservatoire National des Arts et Metiers in Paris. Randal O'Toole is Senior Economist at the Thoreau Institute.

About the Author

Wendell Cox Visiting Fellow
Thomas A. Roe Institute for Economic Policy Studies

Related Issues: Smart Growth