Effect of Continuous Shoulder Rumble Strips and Pavement Marking on Lateral Placement of Vehicles

Shoulder rumble strips and enhanced pavement markings were two key areas identified by AASHTO to reduce run-off-road collisions. The Michigan Department of Transportation is currently testing the effectiveness of placing shoulder rumble strips close to the edge of travel lanes and painting a line on the rumble strip to improve the retroreflective properties of the line. Two issues arise from placing the rumble strips closer to the edge line and moving the paint line onto the rumble strip: the potential increased noise when vehicles crossed over the rumble strips and damage to the pavement if vehicles moved closer to the construction joint between the travel lane and the shoulder. This study found that simply moving the paint line onto the rumble strips resulted in vehicles moving slightly closer to the edge of the travel lane. However, maintaining the current edge line and adding an additional paint line on the rumble strip resulted in vehicles moving away from the edge of the pavement and thus reduced noise and potential damage to the pavement.