One vehicle safety measure fails to improve car accident rates

Some Chicago area drivers may have heard of lane departure warnings and other technological advances designed to reduce the number of car accidents. Other drivers may already have such systems in their cars. But recent crash data on these safety measures, compiled by the Highway Loss Data Institute, give an interesting insight into their effectiveness.

Perhaps most surprisingly, lane departure warning systems failed to deliver on their promise of reducing crashes. In fact, vehicles with the systems were involved in a slightly higher number of car accidents. The difference was statistically insignificant, however, and could be attributed to the fact that the sampled data only represented a small portion of the overall population of vehicles involved in collisions.

Other safety improvements did demonstrably better in preventing crashes, however. Movable headlamps, which can illuminate objects around a bend by turning to the left and right depending on a vehicle’s direction of travel, provided a 10 percent reduction in automobile accidents. Cars that give warnings of an imminent collision saw a drop of 14 percent. Some of those cars will even apply the brakes if drivers do not respond quickly enough to approaching objects.

The study did not show why lane departure warning systems performed poorly compared to other technologies. Researchers theorized, however, that drivers may be triggering the systems when they are in no apparent danger of getting into an accident. Such false positives lead drivers to ignore future warnings or to disable the systems entirely, negating the effect of the lane departure warning when it is truly needed.

Technologies that help drivers avoid accidents are undoubtedly good for everyone on the roads. But even fewer accidents would occur if drivers addressed the root cause of many accidents, which these technologies are designed to combat: distracted driving. Wandering out of one’s lane or rear-ending a car can be the result of a driver devoting too much attention to a text message, the radio or a sandwich.

Source:, “Study Shows Electronic Driver Aids Mostly Help, Occasionally Hurt,” Damon Lavrinc, July 3, 2012.