Safety Effectiveness of Non-Freeway Sinusoidal Shoulder Corrugations

There is a need to determine the safety effectiveness of a newer design of rumble strips (called sinusoidal or "mumble" strips). To date no crash modification factors (CMFs) have been developed for mumble strips, and there has been no safety, noise, or vibration comparisons done between traditional rumble strips and the mumble strips for motorized or nonmotorized travelers (bicyclists). Most installations of mumble strips are not at new locations, but rather traditional rumble strips have been in place and are being replaced with mumble strips. However there is an opportunity in Michigan as there are several hundred miles of mumble strips placed where there were no previous strips.