trips occur during the peak, a 5 percent reduction in total travel would imply a 15 to 20 percent reduction in peak-period travel. This reduction in travel would result in time savings for the average congested peak-period round trip of about 10 to 15 min. As an alternative policy, regionwide parking charges on all employees of $3.00/day would reduce VKT by 1.2 percent in San Francisco and 1.5 percent in Los Angeles. Parking pricing would have a smaller effect on total travel in a congested area because it does not affect through traffic (Table 3-1 and Table 3-2).

The 2 percent reduction in total travel as a result of congestion pricing fees of $0.06/km ($0.10/mi) in the San Francisco Bay Area may seem modest, but when compared with other, nonpricing travel demand management policies, it appears more substantial. By way of comparison, Deakin (1993) estimates that if the Bay Area implemented all reasonably available transportation control measures—including an employer-based trip reduction rule, improved transit services, reduced transit fares, and construction of carpool lanes—these measures combined might have roughly the same impact as congestion pricing on regional travel and emissions, but would impose a substantially higher cost on the region's economy.

Congestion pricing on highways would have broad effects on the entire transportation system by shifting the demand for transportation services away from peak-period highway use by solo drivers. A reduction in the incentives to drive during peak periods would shift some traffic to the off peak, which would increase the efficiency with which the road system is used and reduce the demand for additional capacity. Some motorists would continue to drive during the peak but would elect to share rides with others or change the destinations of their trips. Sharing rides with others would also increase the efficiency with which the system is used by increasing the number of people per vehicle during peak periods.

Some motorists would shift to transit. The improvement in traffic flows that would result from congestion pricing would improve service reliability and speed, which would combine with the direct monetary incentive to make transit considerably more attractive, relative to the automobile, than it is today. The increase in ridership would improve system revenues (Kain, Vol. 2). The revenues could be used to expand service frequency or route coverage, which would make transit service