Mounting evidence proves that lane departure warning systems work as advertised.
The Insurance Institute for Highway Safety (IIHS) has completed a study of police report data that the group says proves that Lane Departure Warning systems are effective. Even more interesting is that they are effective despite many annoyed drivers turning them off.
The study by IIHS’ VP of research, Jessica Cicchino, shows that “…lane departure warning lowers rates of single-vehicle, sideswipe and head-on crashes of all severities by 11 percent and lowers the rates of injury crashes of the same types by 21 percent.” Scale up the math and the finding means that if every passenger car had the systems in 2015, 55,000 injuries would have been prevented. Though the number of fatalities overall was too low for the study to draw a final conclusion, the limited numbers that were available pointed to an 86% reduction in fatal crashes of these types in vehicles with the system. The Highway Data Loss Institute, IIHS’ sibling organization, has not yet seen any decrease in insurance claims from vehicles equipped with the systems. Two other studies, one of commercial trucks with the technology and one of cars in Sweden found a 50% reduction in crashes of the type the systems can prevent.
Note that we are talking about a warning system, not an intervention system. One reason that researchers suspect for the relatively small benefit of just 11% is that in 34% of all lane-drift crashes the driver was found to be incapacitated. More advanced lane departure mitigation systems that nudge a vehicle back onto its proper path are entering the market now, and they may help with these types of crashes.
The same folks that have now proven the systems work, the Insurance Institute for Highway Safety, say drivers often shut off these systems. The IIHS survey shows that lane departure warnings are turned off half of the time by owners. We can understand why. In rural and city driving there are many false alarms as drivers simply avoid common obstacles like joggers.
Automakers know this. Some are now adding a new twist that may resolve the issue of constant warnings that result in a system being shut off, or worse, avoided in showrooms. Automakers like Land Rover are using haptic (tactile) feedback instead of audible warnings. In the case of Land Rover Range Rover Sport, when the vehicle starts to drift towards a lane marker the vehicle vibrates. The effect feels like one is starting to run over cobble stones, or the vibration marks some states cut into highways at the shoulders. This makes perfect sense behind the wheel since we all know what that feeling is and what it means. It is also much more pleasant to ignore when one is crossing over a line purposely. Hopefully, this better type of warning will trickle down quickly to more affordable cars.