The effectiveness of lane departure warning systems – A reduction in real-world passenger car injury crashes

  • Published: Traffic Injury Prevention 18, pp. 225-229, 2017
  • Authors: S Sternlund, J Strandroth, M Rizzi, A Lie, C Tingvall
  • Date Added: 21 Aug 2017
  • Last Update: 21 Aug 2017
  • Format: html


The objective of this study was to estimate the safety benefits of in vehicle lane departure warning (LDW) and lane keeping aid (LKA) systems in reducing relevant real-world passenger car injury crashes.


The study used an induced exposure method, where LDW/LKA-sensitive and nonsensitive crashes were compared for Volvo passenger cars equipped with and without LDW/LKA systems. These crashes were matched by car make, model, model year, and technical equipment; that is, low-speed autonomous emergency braking (AEB) called City Safety (CS). The data were extracted from the Swedish Traffic Accident Data Acquisition database (STRADA) and consisted of 1,853 driver injury crashes that involved 146 LDW-equipped cars, 11 LKA-equipped cars, and 1,696 cars without LDW/LKA systems.

Key Findings:

  • The analysis showed a positive effect of the LDW/LKA systems in reducing lane departure crashes.

  • The LDW/LKA systems were estimated to reduce head-on and single-vehicle injury crashes on Swedish roads with speed limits between 70 and 120 km/h and with dry or wet road surfaces (i.e., not covered by ice or snow) by 53% with a lower limit of 11% (95% confidence interval [CI]).

  • This reduction corresponded to a reduction of 30% with a lower limit of 6% (95% CI) for all head-on and single-vehicle driver injury crashes (including all speed limits and all road surface conditions).


LDW, Lane keeping, Lane departure, injury


This study shows some evidence of the effectiveness of the LDW/LKA systems, however, the parameters defined for the study are very specific, so some of the results may not be able to be generalised to improved vehicle safety as a whole.