option. These changes in driving patterns would reduce congestion and save time for motorists willing to pay the fee.

Congestion pricing could substantially reduce congestion, but it is and has been controversial. Motorists have become accustomed to paying for transportation through fuel, property, and sales taxes, and may greet congestion pricing with the same enthusiasm they have for new taxes generally. Groups representing motorists and commercial carriers at the local and national levels have long opposed tolls of any kind on roadways. Federal law restricts tolls on federal-aid highways and prohibits introducing new ones on Interstates (with the exception of congestion pricing pilot projects, which are discussed later). Americans have long supported gasoline and other user taxes as a means of financing and maintaining highways. Because user taxes charge for a service provided, such taxes are perceived to be fair —even though users with different incomes have different abilities to pay. Charging a premium for road use during peak periods, however, is perceived by many to be unfair to low-income motorists. Some may prefer to continue to use congestion delay as a “tax” that falls on rich and poor alike.

Because of interest in and controversy about congestion pricing, the Federal Highway Administration and the Federal Transit Administration requested that the National Research Council form a study committee to (a) assess the critical issues surrounding congestion pricing and (b) recommend the potential role of congestion pricing as a tool for congestion management, guidelines for evaluation, and fruitful areas for further research. The Research Council's Transportation Research Board and Commission on Behavioral and Social Sciences and Education formed a committee of 14 members. The committee commissioned 17 papers, which were discussed at a symposium held at the National Academy of Sciences in 1993. These papers, and one other commissioned after the symposium, are contained in Volume 2 of this Special Report. Volume 1 contains the committee's overview of the commissioned papers, its conclusions about the prospects for congestion pricing in the United States, and its recommendations.

A motorist who uses a freeway when it is severely congested pays the same money price to use that road as a motorist who drives outside the peak period. Whenever the price of using some valued good does not increase as