Evaluation of Innovative Safety Treatments, Volume 2: A Study of the Effectiveness of Temporary Rumble Strips in Construction Work Zones

The Florida Department of Transportation (FDOT) District 1 office utilized temporary rumble strips on the approach to work zone areas on State Road 31 to alert motorists of lane closures associated with a milling/resurfacing project, from the Lee/Charlotte County line to the Charlotte/Desoto County line. The ability of rumble strips to alert drivers of unusual or hazardous conditions makes them ideal candidates for use on the approach to a highway work zone. In addition to ease-of-use, temporary rumble strips are brightly colored. Thus, temporary rumble strips provide three types of warnings to alert the motorist to the approaching work zone: a physical vibration, an auditory rumble sound, and a visual cue. In addition to making drivers more alert, it is anticipated that temporary rumble strips will impact travel speeds. This report documents the findings and conclusions of a field experiment conducted on State Road 31 at various test (with temporary rumble strips) and control (without temporary rumble strips) locations to determine the effectiveness of temporary rumble strips in reducing travel speeds approaching highway work zones. The evaluation consisted of measuring travel speeds of motorists as they approached work zone areas with and without temporary rumble strips, and comparing changes in average speed, speed distribution, and the proportion of speeding vehicles. The results of this evaluation indicated that the use of temporary rumble strips in advance of construction work zones reduced vehicular speeds once motorists encountered the temporary rumble strips. Therefore, the use of temporary rumble strips prior to a construction work zone may be a practical countermeasure to reduce vehicular speeds through the work zone.