To help local jurisdictions review their parking policies as mandated by Washington State's new commute trip reduction legislation, the Municipality of Metropolitan Seattle conducted a parking utilization study in 1991 to assess the demand for parking, compared with supply, at employment sites throughout King and south Snohomish counties. A total of 36 employment sites in suburban, noncentral business district areas were included in the study. The sites represented two land uses:(a) professional office and (b) industrial sites (both light industrial and manufacturing). Results showed that the average parking supply was 30% greater than the average parking demand. The average number of parking spaces per 1,000 gross sq ft (GSF) was 3.15, compared with a demand of 2.54 (a 24% excess). If projected employment and demand figures are used, a 13.5% excess parking supply still exists, in relation to spaces per 1,000 GSF. On the basis of the results of this study, it is recommended that local jurisdictions consider reducing their parking requirements, at least for professional office uses. The reduction of parking requirements in local codes will apply only to new or expanding developments; therefore local jurisdictions are encouraged to establish an administrative review process so that property owners of existing work sites, on behalf of employers, may request reductions in parking supply.