Post warning messages on DMS that describe how drivers should react to hazardous conditions rather than just notifying them of the hazard ahead.

Testing effectiveness of dynamic message sign warnings in foggy conditions.

Date Posted
02/06/2018
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Identifier
2018-L00803

Impact of Dynamic Message Signs on Driver Behavior Under Reduced Visibility Conditions

Summary Information

Fog along roadways is a dangerous hazard that leads to crashes resulting from limited visibility. To solve this issue, early warning systems involving Dynamic Message Signs (DMS) or other types of devices are used to alert drivers of the impending visibility condition so that they are prepared. This research focuses on testing the effectiveness of one form of warning systems to investigate how it impacts driver behavior in foggy conditions.

Methodology

A simulation study is developed to test variables of interest including: Roadway Type, Fog Level, DMS Presence, Beacon Presence, Traffic Volume, and DMS Message Provided. Using a factorial design, 24 scenarios are created by randomizing the variables listed using statistical software to be tested on 72 volunteer participants. Using a NADS MiniSim Driving Simulator, the participants driving behavior is recorded including speed and breaking behavior under an initial clear condition followed by a reduced visibility fog condition.

Lessons Learned

Post warning messages on DMS that describe how drivers should react to hazardous conditions rather than just notifying them of the hazard ahead. Presence of a DMS does not have a significant impact on the average change in driver speed until the fog condition becomes the most severe. Messages advising drivers on how to drive (e.g., "reduce speed") were found to be more effective than those solely warning of the presence of a hazard (e.g., "fog ahead").