Field Test Results of a Road Departure Crash Warning System: Driver Utilization and Safety Implications

The Road Departure Crash Warning System Field Operational Test (RDCW FOT) was conducted to assess the safety impacts, driver acceptance levels, and the maturity of road departure crash warning systems as installed on a light vehicle platform. This paper presents the experimental design, performance of the road departure system in naturalistic use, and analyses of safety impacts of the technology using surrogate measures. Use of the system led to a 50% reduction in the observed rate of events in which the equipped vehicle came within 0.1 m of a lane edge in steady-state lane-keeping situations. Lane changes performed without the use of a turn signal were reduced by 43% on freeways and ramps and 24% on surface roads. Levels of lateral acceleration in curves was not significantly different, except on ramps, where a significant change in the 90th percentile values of lateral acceleration were observed for a within-subject comparison. There were no observed effects of risk homeostasis and no evidence of significant negative unintended consequences.