A study was conducted to discover if the long-term effect of the lap belt reminder system on 1972 cars would be to increase belt-use frequency. Automobile Club of Southern California employees driving fleet vehicles equipped with specially designed hardware were used to perform the study. Driver lap belt usage was measured with the buzzer and light reminder system disconnected (to determine use rates under normal conditions) and then with it operating (to determine use rates in response to the reminder system). Conclusions are: 1. Approximately one third of the individuals who did not use lap-belts will become users for the majority of vehicle trips when the reminder system is operative. The reminder system will also increase usage of lap belts by individuals who used them only on occasion. 2. This study could not establish a significant relationship between lap belt use (with and without reminder system) and miles per vehicle trip, trips per day, and test subject demographics. 3. Approximately one half of the individuals will circumvent the reminder system. The majority will manipulate the lap belts, not increasing lap belt use. The minority will disconnect the electrical system. Their subsequent behavior in terms of an increase, no change, or decrease in lap belt use may vary.