The Lane Departure Warning (LDW) system is a crash-avoidance technology which warns drivers if they are drifting (or have drifted) out of their lane or from the roadway. This warning system is designed to reduce the possibility of a run-off-road crash. This system will not take control of the vehicle; it will only let the driver know that he/she needs to steer back into the lane. An LDW is not a lane-change monitor, which addresses intentional lane changes, or a blind spot monitoring system which warns of other vehicles in adjacent lanes. This informational report applies to OEM and after-market Lane Departure Warning systems for light-duty vehicles (gross vehicle weight rating of no more than 8500 pounds) on relatively straight roads with a radius of curvature of 500 m or more, and under good weather conditions.