Arlington, Virginia -- August 27, 2017 -- There seems to be little doubt that lane departure warning technology is preventing collisions, according to new research from the US-based Insurance Institute of Highway Safety (IIHS). A separate study conducted by IIHS also seems to show that blind spot detection is also cutting down on lane-change crashes.
The studies are the latest in a series by Jessica Cicchino, IIHS Vice President for Research, that evaluates different crash avoidance features by looking at data from police-reported crashes.
Police reports include information on the circumstances of a crash, making it possible to look specifically at the types of crashes that particular technologies are designed to address, rather than just looking at crash rates generally.
Cicchino's previous studies found that front crash prevention with autobraking cuts the rate of front-to-rear crashes in half and that rearview cameras can prevent about one in six backing crashes.
Results of the new study indicate 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. The analysis controlled for driver age, gender, insurance risk level and other factors that could affect the rates of crashes per insured vehicle year.
"This is the first evidence that lane departure warning is working to prevent crashes of passenger vehicles on US roads," says Cicchino. "Given the large number of fatal crashes that involve unintentional lane departures, technology aimed at preventing them has the potential to save a lot of lives."
On many vehicles, lane departure warning is bundled with front crash prevention, making it impossible to separate the effects, as the insurance data don't include the type of crash. And on the few vehicles studied that don't bundle the feature, no benefits for lane departure warning have been found.
The new study included vehicles with optional lane departure warning from six manufacturers: General Motors, Honda, Mazda, Mercedes-Benz, Subaru and Volvo. The automakers provided information about the presence of optional features on specific vehicles by vehicle identification number (VIN).
Cicchino also researched the efficacy of blind spot detection systems, which provide a visual alert when an adjacent vehicle is in the driver's blind spot. In this case, she focused on crashes in which the vehicles were changing lanes or merging. Fiat Chrysler, General Motors, Honda, Mazda, Mercedes-Benz and Volvo vehicles were included.
Controlling for other factors that can affect crash risk, blind spot detection lowers the rate of all lane-change crashes by 14 percent and the rate of lane-change crashes with injuries by 23 percent. Although only the reduction in crashes of all severities was statistically significant, the effect for injury crashes was consistently in the expected direction for five of the six manufacturers studied.
"Blind spot detection systems work by providing additional information to the driver. It's still up to the driver to pay attention to that information and use it to make decisions," Cicchino says. "That said, if every passenger vehicle on the road were equipped with blind spot detection as effective as the systems we studied, about 50,000 police-reported crashes a year could be prevented."