Lane departure warning

Description
Warning is given to the driver in order to avoid leaving the lane unintentionally. Video image processing is the most important technology. Warnings can be acoustic, visual or haptic.

Impacts
Only restricted evidence of the safety effects exist. The system should affect especially accidents in which two vehicles collide frontally, a vehicle leaves the road without colliding with another vehicle, and in which two or more vehicles collide laterally. Reductions in both accident number and severity are expected. Current accident reduction estimate is ca 10%.

Studies

The number of unintentional lane crossings decreased with 35 % on secondary roads and on highways because of lane departure warning. Drivers also kept better course to prevent warnings.	A field operational test with 20 cars conducted in the Netherlands	Alkim, T. P., Bootsma, G., Hoogendoorn, S. P.	2007	Dutch Field Operational Test experience with “the Assisted Driver”, Proceedings of the 14th World Congress on ITS, 9-13 October 2007, Beijing, Peoples' Republic of China.
Lane departure warning system was estimated to reduce the number of single vehicle road departure crashes by 17-19 % and the number of rollover crashes by 17-23 % when applied in large trucks (> 10 000 lbs).	The results are based on a 12 months long field operational test involving 22 trucks.	Orban, J., Hadden, J., Stark, G. and Brown, V.	2006	Evaluation of the Mack Intelligent Vehicle Initiative Field Operational Test, Final Report
25% reduction in accident number and 25% reduction of accident severity in head-on collisions. 25% reduction in accident number and 15% reduction of accident severity in left-roadway accidents. 60 % reduction in the number of accidents and a 10 % reduction in accident severity for side collisions.	Estimates are based on accident statistics assuming a 0.5 sec quicker reaction to lane departure.	Abele, J., Kerlen, C., Krueger, S., Baum, H., Geißler, T., Grawenhoff, S., Schneider, J. & Schulz, W.H.	2004	Exploratory Study on the potential socio-economic impact of the introduction of Intelligent Safety Systems in Road Vehicles. SEiSS. VDI/VDE Innovation + Technik GmbH and Institute for Transport Economics at the University of Cologne
Lane departure warning systems installed in heavy goods vehicles would decrease the number of accidents involving heavy goods vehicles by 10%	Trial involving 40 professional drivers and 36 heavy duty vehicles.	Korse, M.	2003	Results of the trial with the Lane Departure Warning Assistant-system. Rijkswaterstaat 11 September 2003