This study investigates the effectiveness of an automated motorist warning system (AMWS) in the city of Ft. Lauderdale, Florida. The system evaluated warned motorists of the presence of wet pavement on a freeway ramp at an urban interchange. Comparing vehicle speed data from an evaluation period of 6 weeks prior to the activation of the AMWS and 9 weeks following the activation indicate a significant reduction of vehicle speeds during wet pavement conditions. The evaluation determined that vehicle speeds were 10.2 mi/hr lower during heavy rain and 4.6 mi/hr lower during periods of light rain.
The after evaluation period was too short to provide an accurate comparison with crash data collected during the 6 years prior to the AMWS implementation. However, the author felt that the lack of accidents during the 9-week after evaluation period was promising. There were 4 “run-off” crashes reported during the first week of system operation, however this data was considered an anomaly.