DETROIT - Collision-warning systems and lane-departure alerts are among the most promising new safety technologies and could potentially prevent thousands of fatal accidents, according to a study by an insurer-funded group.
The Insurance Institute for Highway Safety studied five safety systems that are mostly on luxury vehicles. The study was to be released last week at the SAE International conference for engineers in Detroit.
Frontal crashes account for 40 percent of crashes on US roads each year, or around 2.3 million, the institute said. Of those, around 7,100 are fatal.
Collision-warning systems alert drivers to an impending crash by sounding alarms, flashing lights, or tightening seat belts and - in some cases - applying the brakes.
Lane departure warning systems detect when a driver is changing lanes unintentionally, such as when the turn signal isn't used. The system alerts the driver by vibrating the steering wheel or using an audible or visual warning. Such systems could prevent some of the 483,000 collisions and sideswipes caused each year when drivers swerve out of their lanes. Those accidents cause around 10,300 deaths per year.
The Arlington, Va.-based institute said blind spot detection systems, adaptive headlights, and emergency brake assistance show less potential because they would prevent fewer crashes and deaths. Adaptive headlights move in the direction of the car when it is turning, while emergency brake assistance detects panic breaking and boosts brake pressure. Those systems together could prevent 1.1 million total crashes, but the crashes are not as deadly. For example, the institute estimates that only 428 deaths each year are due to a driver's failure to detect something in a blind spot.
The institute stressed that not all accidents or deaths can be prevented and that the systems aren't on enough vehicles to fully evaluate their benefits. Volvo is the only brand that puts all five technologies on some of its models. Acura and Mercedes also have collision-warning systems with automatic braking, while Audi, BMW, Buick, Cadillac, and Infiniti have lane departure warning systems.
"What we can do is compare their promise based on how many crashes they have the potential to prevent and how they'll prevent them," said the institute's president, Adrian Lund.
The safety systems all work in different ways, but the institute said research shows systems with automatic features, such as collision systems that apply brakes, are the most effective. Systems that simply warn drivers with a beep or a light and then require drivers to take action may not be as effective because drivers may not act appropriately.
The systems also could backfire if drivers go faster or pay less attention because they expect the gadget will take care of them. Several studies have indicated that drivers increase their nighttime speeds on curvy roads when reflector posts or markers are installed, so they might react the same way to adaptive headlights, the institute said.
Another danger is that drivers will turn off crash avoidance systems because they're annoying or could activate continuously in urban traffic, the institute said.
The institute examined data from two-car crashes from 2002 through 2006 and assigned crashes by type to the technology that is supposed to prevent them. They subtracted crashes where drivers were deliberately turning, merging, or changing lanes and collisions that occurred off the road because most safety systems are designed to detect traffic but not other obstacles.