Effects of environmental design and police enforcement on violations of a handicapped parking ordinance.

This study presents two experiments that evaluate strategies to reduce violations of a handicapped parking ordinance. The first experiment compared effects of upright versus ground handicapped parking signs on percentage of intervals in which cars were parked illegally. Introducing upright signs produced an immediate reduction in the percentage of intervals of inappropriate use of parking spaces. The second experiment examined effects of a police enforcement program on percentage of intervals of inappropriate use of parking spaces and frequency of inappropriately parked cars. Results showed consistent reductions in percentage of intervals of inappropriate use and number of inappropriately parked cars compared with a control site where no enforcement program was introduced. Implications of the research data for law enforcement and public policy are discussed.