An automated wet pavement warning system installed on a freeway ramp in Ft. Lauderdale reduced vehicle speeds by 10.2 mi/hr during heavy rain and by 4.6 mi/hr during periods of light rain.
Made Public Date


Ft. Lauderdale
United States

Are Simplistic Weather-Related Motorist Warning Systems "All Wet"?

Summary Information

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.

See also:

Wet and Wild: Developing and Evaluating an Automated Wet Pavement Motorist Warning System. Paper presented at the 80th Transportation Research Board Annual Meeting, Washington, DC. 7-11 January 2001.