Rumble Strips

Rumble strips provide audible and vibratory alerts to drivers whose vehicles have departed the travel lane and warns them that a steering correction is needed.

Shoulder rumble strips are narrow, linear bands of indentations (bumps) installed between the travel lane's edgeline and the paved roadway shoulder. Edgeline rumble stripes are a particular subset of rumble strips installed on the pavements' edgeline. Rumble strips provide audible and vibratory alerts to drivers whose vehicles have departed the travel lane and warns them that a steering correction is needed. The treatment can be installed on new or existing pavements.

Centerline rumble strips (CLRS) are transverse grooves that are placed along the centerline of a two- or four-lane undivided roadway. These devices can be installed on new, existing, or reconstructed asphalt or portland cement concrete (PCC) pavements.

Similar to shoulder rumble strips, CLRS provide a tactile and audible alert to drivers whose vehicles are crossing the centerline and warns them that a corrective action is needed. Due to their ease of installation and maintenance, CLRS have been found to be useful for reducing the number of cross-centerline multi-vehicle crashes at a relatively low cost.

More information about shoulder rumble strips is provided in Chapter 3, and information about edgeline rumble strips is provided in Chapter 4 of Lane Departure Safety Countermeasures: Strategic Action Plan for the Iowa Department of Transportation (Nambisan and Hallmark 2011).

A summary of crash modification factors for shoulder and centerline rumble strips is provided here.

Reference

Nambisan, Shashi and Shauna Hallmark. Lane-Departure Safety Countermeasures: Strategic Action Plan for the Iowa Department of Transportation, Institute for Transportation, Iowa State University, 2011.

Image: Gapped milled shoulder rumble strip pattern on a rural highway

Gapped milled shoulder rumble strip pattern (Iowa DOT)

Image: Close-up view of milled shoulder rumble strips

Close-up view of milled shoulder rumble strips (Shauna Hallmark et al./Institute for Transportation)

Image: Rural curve with both shoulder and centerline rumble strips

Curve with both shoulder and centerline rumble strips (Shutterstock)

Image: Shoulder rumble strips on a rural highway

Newly installed shoulder rumble strips (Shutterstock)


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