are an effective countermeasure for reducing roadway departure crashes. The noise and vibration produced by rumble strips alert drivers when they leave the highway. Rumble stripes is the term used for rumble strips painted with a retroreflective coating to increase the visibility of the pavement edge at night and during inclement weather conditions.
KDOT uses all types of shoulder rumble strips, depending on the need and the material. The groove pattern can be installed intermittently or continuously. The groove pattern, depth, width, shape, and spacing may also change with the road agency. Milled rumble strips are made by a machine with a rotary cutting head, which creates a smooth, uniform, and consistent groove into the pavement.
Different dimensions of milled rumble strips provide different amounts of sound and vibration in a passenger car. The wider and deeper the rumble strip, the more sound and vibration. Cars and trucks make different sounds while driving over the strip. It's important for KDOT to inspect the quality and construction of the rumble strips in order to create right amount of vibration and noise to do what they are intended to do, alert drivers to the fact they are no longer on the roadway.