Experience with speed activated message systems at work zones in Virginia.
Bristol, Virginia, United States
Effectiveness of Changeable Message Signs in Controlling Vehicle Speeds in Work Zones: Phase II - Final Report
Summary Information
This Phase II study was conducted as a follow up study to a Phase 1 study that found that radar equipped dynamic message signs (DMS) are more effective than Uniform Traffic Control Devices (MUTCD) signs at reducing vehicle speeds in work zones during construction projects that last one week or less. The purpose of the Phase 2 study was to confirm the findings of the Phase 1 study and evaluate the effectiveness of radar equipped DMS at reducing vehicle speeds in work zones in place up to seven weeks.
The DMS units were placed a short distance behind the first set of road tubes and the radars were set to detect the speeds of incoming vehicles at a distance of about 400 ft to 600 ft away. When a speeding vehicle was detected the DMS was programmed to flash the message "YOU ARE SPEEDING SLOW DOWN."
Data collection was carried out over several weeks to study the effect of duration of DMS deployment on vehicle speeds during the construction season of 1995 and 1996.
RESULTS
- Based on a statistical analysis of the data collected with and without DMS messages the study found that radar equipped DMS can reduce vehicle speeds by 8 to 9 mi/hr.