BACKGROUND: Centerline, edge line, and shoulder rumble and mumble strips are road safety features to alert inattentive drivers to potential lane departure. These strips are most commonly a pattern of grooves milled into the pavement surface; those constructed in inadequate pavement may lead to premature deterioration of the surrounding pavement. Much of the research on rumble and mumble strips has focused on their ability to alert inattentive motorists with limited consideration to their long-term performance or their impact on the surrounding pavement. The performance of rumble and mumble strips depends not only on their maintenance and construction features but also on those of the surrounding pavement (e.g., pavement surface type, thickness, condition, and treatment; and snow and ice control operations); there are no widely accepted guidelines that address the maintenance and construction aspects of rumble and mumble strips. 

There is a need to develop guidelines that address the different aspects of maintenance and construction of rumble and mumble strips on flexible and rigid pavements. Such guidelines will help highway agency personnel in making decisions regarding the maintenance and the construction of these strips and implementing more balanced and more cost-effective solutions.

OBJECTIVE: The objective of this research is to develop guidelines for the maintenance and construction of rumble strips on flexible and rigid pavements. Mumble strips are considered a form of rumble strips and should be included. For purposes of this research, the safety aspects of rumble strips will not be addressed.

Status: Research is complete. The contractor's final deliverable that includes the research report and the proposed guidelines is available at  https://www.nationalacademies.org/osdocs/NCHRP14-46_FinalReportAndGuidelines.pdf