Rumble strips consist of a series of roadway indentations, raised traffic buttons or profile markings to alert inattentive drivers that their vehicle has left the travel lane by making vibrations and sound.

Rumble strips can be placed on roadways with a posted speed limit of 50 mph or more. Rumble strips can be installed along the road shoulder, the centerline or adjacent to the median.

Transverse rumble strips are intended to alert drivers to special conditions including:

  • Intersections with sight restrictions
  • Unexpected intersections
  • Toll plazas
  • Unexpected horizontal curves
  • Railroad crossings

Shoulder and center line rumble strips illustration

Illustration: Shoulder and Center Line Rumble Strips

Shoulder and center line rumble strips photo

Photograph: Shoulder and Center Line Rumble Strips

A. Shoulder line

B. Center line

C. Rumble strip