This report summarizes a feasibility evaluation of a speed monitoring system that provided speed warning feedback to drivers enrolled in a voluntary program, with particular emphasis on at-risk drivers, especially chronic speeders. This project included a review of driver monitoring and feedback products, a focus group of chronic speeders, and a naturalistic field study. The field study was designed to determine the effects of immediate feedback on driver behaviour as well as answering a “feasibility” question related to implementing such a program on a larger scale. Drivers with at least three speeding violations in the past three years were recruited through the Maryland Motor Vehicle Administration. After a two-week baseline period, the alert system was activated and driving behaviour was monitored for any changes for approximately four weeks. (Some participants experienced the alerts for eight weeks.) Subjects were monitored (silently) for a follow-up phase of two weeks (or four weeks; for the longer duration subjects). During the treatment phase, alerts were provided to the drivers when their speeds exceeded the posted speed limit by more than 8 mph. The findings are encouraging, and suggest that the verbal alerts provided were successful in producing statistically significant but small short-term changes in driving behaviour. Overall, the average proportion of speeding above the alert threshold declined significantly during the course of the treatment phase, indicating that the presence of alerts does have a deterring effect on speeding behaviour. Once the alerts were silenced, there was evidence suggesting a sustained change in driving behaviour for some participants. Although the proportion of speeding above the threshold during the two-week follow-up period was higher than the proportion of speeding during the treatment phase, the follow-up speeds were lower than those recorded during the baseline phase for some participants. (Author/publisher)
Samenvatting