uals to choose whether to pay a congestion fee will result in a more efficient outcome.

Congestion pricing could take several forms. The most straightforward example is to add an extra fee to an existing toll or to add a peak fee on an untolled route or bridge. The charge itself could be a simple peak/off-peak differential, or it could vary according to the demand imposed on a facility at a specific time. In more complex forms, it could apply to traffic on all routes entering a congested area, and the charge could vary according to the congestion on specific routes and the distance traveled. Alternatively, all motorists parking in a congested area could be assessed an extra fee to encourage them to use other modes or to share rides.

In practice, congestion pricing could take six basic forms (Gomez-Ibanez and Small forthcoming):

• Point pricing, in which a highway user passing a point at a specific time is charged a fee for passing that point regardless of the distance traveled on a specific route (Figure 2-1);

• Cordon pricing, in which users wishing to enter a congested area are charged fees at each entry point into the area (Figure 2-1);

• Zone pricing, in which users traveling within a cordoned area also pay a fee;

• Higher charges for parking in congested areas, with particular emphasis on parkers traveling during the most congested period;

• Charges for distance traveled within a congested area or on a congested route (Figure 2-2); and

• Congestion-specific charges, in which users would be charged for both time spent and distance traveled.

Currently the only forms of congestion pricing in operation are cordon pricing in Singapore and charges for distance traveled on the A-1 toll road outside Paris. Cordon pricing is also being applied in three Norwegian cities, but because the tolls do not vary by time of day (with a minor exception in Trondheim), these are not considered congestion pricing.

The active proposals for congestion pricing in the United States are for point pricing. A hybrid version of point pricing has also been proposed in the United States; in this version, solo drivers would be provided with the option of paying to travel on underused high-occupancy-vehicle (HOV) lanes.

Front Matter (R1-R10)

Executive Summary (1-15)

1 Introduction (16-26)

2 Theory and Experience (27-38)

3 Possible Effects (39-57)

4 Technical and Political Feasibility (58-80)

5 Design, Evaluation, and Research (81-96)

6 Summary (97-103)

Appendix A: Traffic Congestion (104-116)

Appendix B: Theory, Experience, and Estimated Effects (117-139)

Study Committee Biographical Information (140-146)