renewed; this would then make a higher proportion of leases subject to the cash-out option.

Careful and extensive evaluation of any congestion pricing program introduced in the United States is the highest priority for research. Research is also encouraged in other areas:

• The impact of congestion pricing on business logistics and commercial carriers;

• The extent to which transit services and revenues could be improved as a result of congestion pricing and how this might benefit lower-income users;

• Development of improved models for simulating household travel changes in response to pricing and other travel demand management strategies;

• Improved measures of congestion;

• Efficiency and productivity benefits of congestion pricing;

• Development of a program to ensure that the United States learns from current and emerging experiments with road pricing in other parts of the world;

• Measurement of long-term land use changes that might occur in response to congestion pricing;

• Studies of how the benefits and burdens of policies such as congestion pricing shift over time through labor, land, and retail markets;

• Constituency building and the local politics of implementation; and

• The efficacy of distributing tradable permits to all motorists for driving during peak periods as an alternative to charging congestion tolls (this option would allow motorists to be “bought off” of congested routes rather than being “tolled off”).