Particular emphasis is placed on specific projects in which the police have increased their enforcement and the changes have been measured and reported. Most of the studies were completed in the 1970's. Research covering the increased enforcement of traffic laws and subsequent reduction in accidents is reviewed, followed by a brief discussion of literature covering the enforcement of laws prohibiting driving while under the influence of alcohol. Remaining sections describe the effects of increased enforcement and fewer traffic violations and include cost-benefit analyses. The projects include 18 State/city listings as well as several foreign countries, such as Denmark, Great Britain, New Zealand, and Canada. The critique notes that the major shortcoming with the experiments has been the lack of any clear causal link between increased traffic law enforcement and reduced accidents. Even studies which have established a link have failed to identify exactly which factors resulted in a reduction. However, it seems clear that an increase in the number of officers on traffic patrol at times and locations noted for a high frequency of accidents does result in fewer accidents. A bibliography of about 125 references is included.