Rumble strips are a road safety feature designed to alert drivers when they are departing their driving lane. They can be a series of trough-like sections that are ground out of the asphalt (typically ½” to 3/8” deep). The depth, width and pattern can vary.
Rumble strips are installed along the direction of travel following an edgeline or centerline. Edgeline and centerline rumble strips are used to reduce crashes caused by vehicles leaving their lanes, such as head-on collisions or run-off-road collisions. When motorists cross the rumble strips, they are alerted by sound and strong vehicle vibrations.
Transverse rumble strips are also installed to alert motorists. These rumble strips are installed in the travel lanes where vehicles will cross over them. They are used to alert drivers of upcoming intersections or hazards ahead. These type of rumble strips are commonly used when approaching Stop signs.