Rumble strips are a method of reducing roadway departure crashes. The noise and vibration produced by rumble strips alert drivers when they leave the lane. Research has shown that rumble strips can reduce severe crashes.
Center line rumble strips help to reduce head-on collisions and cross-over crashes. These are often found in the center of a two-lane, two-way highway. In one study, center line rumble strips were shown to reduce the crash frequency by 45% on rural two-lane roads.
Shoulder rumble strips help to reduce run-off-the-road crashes. They are used to warn drivers when they have drifted from their lane. In one study, crash frequency dropped 36% on rural two-lane roads and 17% on rural highways.