What is a Lane Departure Warning?

A lane departure warning is a safety system in a car which alerts the driver when the car drifts out of its lane. In addition to being available for cars, lane departure warning systems can also be installed in trucks, buses, and other vehicles. The use of such systems can dramatically cut down on accidents caused by inattentive driving, making the road safer and reducing expenses related to motor vehicle accidents, such as legal claims lodged against inattentive drivers.

Lane departure warning systems work slightly differently in various models of car. Most have cameras which are designed to see the markers used to outline the lanes of a road, and the cameras can distinguish between yellow and white markings. Other cars use different types of sensors. In all cases, when the sensor detects that a car appears to be drifting out of its lane, some sort of alarm is issued, such as a popup on the display panel of the car or a buzzer.

When a turn signal is enabled, indicating that the driver intends to turn or change lanes, the lane departure warning will be disabled, as the driver clearly intends to move out of the lane. In all other cases, the warning system will be active. Lane departure warnings can alert tired and sleepy drivers that they are drifting, perhaps because they are losing focus, and that it might be time to take a break, and they also also warn fully alert drivers that they may not be paying enough attention to their position in the road.

Safety pioneers like Volvo were among the first to install lane departure warning systems, along with other sensor systems designed to increase driver safety by looking for problems with the driver, the car, or the roadway. The introduction of such systems to the trucking industry has also had a profound impact, reducing accidents and making trucking much safer.

These systems are primarily available fully installed in new cars, although some companies offer systems which can be used to retrofit existing vehicles for safety. A car with a lane departure warning system may cost less to insure, as insurance companies usually reduce the rates for drivers with special safety features in their cars. This can reduce the cost of the car over its lifetime, even if having such a system adds to the cost of a car at the time of purchase.