As used in this report, "selective enforcement" involves the selection of certain times and sites for which specific traffic laws are to be stringently enforced. A significant problem with current selective enforcement projects is that projects have been funded where no problem has been documented. An associated problem is a general failure to target problems within a locality, largely because both State and local police forces have not collected data adequate to identify problems or evaluate the effectiveness of selective enforcement projects. State police and many localities have also failed to identify realistic and measurable immediate, intermediate, and ultimate objectives. Steps in effective selective enforcement projects are to collect site-specific and time-specific crash data; identify problematic times, days, sites, and offenses; establish realistic and measurable immediate, intermediate, and ultimate goals; and develop an enforcement plan of site-specific and time-specific enforcement activity. The plan should then be implemented and accompanied by data collection on enforcement activities and an evaluation of project effectiveness. 2 figures, 9 references.