with through traffic, which in some areas is the most significant source of congestion. Parking charges, however, can be designed to influence the choices of solo drivers. The “cashing out” of employee parking that has been adopted in California law requires employers who lease parking from a third party to provide their employees with the option of taking the cash equivalent of the employee parking benefit (Shoup, Vol. 2). Drawing on case studies of individual companies that changed their parking fees, Shoup estimates that if offered in the greater Los Angeles area, the cash-out option would reduce the number of solo driver trips to work by 20 percent (Shoup, Vol. 2, Table 5).

The California law was written to minimize adverse impacts on employers. Those that lease parking from third parties in a large block, and are therefore unable to return a few spaces, are exempt from the parking cash-out requirement until the term of the lease expires. Once the lease has been renewed, the employer must cash out parking to employees who prefer this option. Under this circumstance, the employer who wishes to minimize costs will need to negotiate with the lessor to reduce the number of spaces being leased. The law has another provision that requires cities and counties to reduce the parking requirements in zoning regulations for new and existing structures. This provision is designed to give lessors an incentive to convert land devoted to parking to higher uses. The ways in which the California law is designed to create benefits for employees, employers, and the general public are discussed in detail in Shoup's paper in Volume 2.

Borins, S. 1988. Electronic Road Pricing: An Idea Whose Time May Never Come. Transportation Research, Vol. 22A,No. 1, Jan., pp. 37–44.

Button, K. 1982. Road Pricing: Some Practical and Economic Considerations for Its Introduction in Britain. Logistics and Transportation Review, Vol. 18, No. 4, pp.353–371.

Dawson, H., and I. Catling. 1986. Electronic Road Pricing in Hong Kong. Transportation Research, Vol. 20A, No. 2, pp. 129–134.

Gomez-Ibanez, J., and K. Small. Forthcoming. NCHRP Synthesis of Highway Practice: Road Pricing for Congestion Management: A Survey of International Practice.TRB, National Research Council, Washington, D.C.

Hau, T. 1992. Congestion Charging Mechanisms: An Evaluation of Current Practice .Policy Research Working Papers. WPS 1071. The World Bank, Washington, D.C.

Wohl, M., and C. Hendrickson. 1984. Some Practical Pricing Problems. In Transportation Investment and Pricing Principles, Chap. 13, John Wiley and Sons, New York.

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)