Deterring the drinking driver: the Stockton experience.

The effectiveness of drunk driving enforcement patrols is generally assumed. However, few adequate evaluations are available in the traffic safety literature. The U.S. Department of Transportation funded a special program in Stockton, a city with a population of 120,000 in the central valley of California, to test the effectiveness of special drunk driving patrols on weekend evenings, applied within a setting in which no other major alcohol safety programs were present. The objective of this effort was to determine the effectiveness of a "traditional" approach to enforcing driving while impaired (DWI) laws; one in which innovative procedures such as sobriety checkpoints were not used. The results indicated that nighttime collisions in Stockton were reduced during the three and a half year period of the special enforcement program.