Rumble Strips Are Busy Saving Lives
What they are
Rumble strips are a low-cost measure used to address one of the most serious types of traffic crashes: a lane departure crash. They consist of a set of transverse grooves applied on the shoulder or centerline of a roadway.
What they do
Rumble strips provide a tactile and audible warning to alert inattentive (distracted, drowsy, unfocused, etc.) drivers who may unintentionally drift out of their lane. This warning gives the driver an opportunity to correct their action or reduce speed, which may help them avoid or reduce the severity of a crash.
The Michigan initiative
Shoulder rumble strips have been in use all over the country for many years and their safety benefits are well-documented, but centerline rumble strips are relatively new. Michigan is leading the way with this safety feature. Between 2008 and 2010 MDOT undertook the largest initiative of its kind to install 5,400 miles of centerline rumble strips (and an additional 1,700 miles of shoulder rumble strips) on high-speed rural highways across the state. This system-wide installation provided a unique opportunity to evaluate the effectiveness of non-freeway rumble strips, which was done through a two-phase research project.
Safety by the numbers
A before-and-after crash study performed for the 2008-2010 installation locations found significant reductions across all crash severities and lane departure crash types, including:
- 50 percent reduction in head-on crashes
- 46 percent reduction in run-off-the-road crashes
- 51 percent reduction in fatal crashes
- 41 percent reduction in incapacitating injury crashes
Rumble strips have become a safety standard on MDOT roadways, and will continue to save lives in the years to come as Michigan moves Towards Zero Deaths.
View MDOT’s Centerline Rumble Strip Brochure
View MDOT’s Non-Freeway Rumble Strip Research