Of the various explanations of the decline considered, only the city's forfeiture ordinance achieved statistical significance and retained significance across several specifications. This ordinance allowed for the forfeiture to police of any vehicle used in an illegal speed contest. Although no vehicles were seized under this ordinance during the period of the study, this fact apparently showed its deterrent effect. The authors believe the deterrent effect must have occurred through word-of-mouth among racers, since neither press coverage nor law-enforcement variables were significant. Other factors considered were the enactment of an ordinance that made attendance at an illegal street race an arrestable offense; an increase in the number of police-approved races; press coverage of a murder prosecution related to an illegal race; and enhanced law-enforcement activity aimed at curbing the problem. Several regression models were estimated in order to determine which of the aforementioned factors were linked with street-racing casualties. Data came from street-racing injury and fatality data provided by the San Diego Police Department's DragNet team. Counts of approved racing events were obtained from "Race Legal," the organization that organizes the races. Press coverage data were collected from Lexis-Nexis. Enforcement data were provided by the police and City Attorney's Office. 4 tables and 23 references