A number of luxury vehicles—and a few other tech-focused models like the 2010 Toyota Prius and 2010 Ford Taurus—now offer features designed to warn you when you stray from your lane, whether due to inattention or drowsiness, or might not notice what's in your blind spot. But typically these systems often come as part of technology packages carrying price tags in the thousands, and for those purely interested in how it will help keep them safe there's been a relative absence of data.
Although there's still no solid data on how many accidents these systems might be avoiding or how many lives saved, a new study from the Insurance Institute for Highway Safety (IIHS), published in its most recent Status Report, suggests that in most cases early adopters are embracing these systems and finding them helpful, with the impression that they do provide a worthwhile safety boost.
The IIHS studied owners of 2007-08 Volvo models equipped with automatic braking, lane departure warning, side view assist, and active headlights (the Volvo S80 has them all), along with 2005-09 Infiniti models (including the Infiniti M35/45, EX35, and FX35/45/50) with either lane departure warning or lane departure prevention.
In previous research, the IIHS had singled out forward collision and lane departure systems as the most promising for helping to avoid crashes, including fatal ones, or lessen their impact.
Volvo lane departure warningEnlarge Photo
The latest Volvo "Collision Warning with Auto Brake" system uses radar-sensor data for vehicles ahead and automatically alerts the driver if they're getting too close; it actually applies the brakes if the system judges a collision unavoidable. The blind-spot system, which Volvo calls BLIS, uses rear-facing cameras in the mirrors, with lights built into the lamps that light up when a vehicle is currently in the blind spot.
The lane-departure systems from Volvo and Infiniti use a camera system to recognize lane markings, sounding an alert (and flashing a light, in the Infiniti) if the driver strays out of the lane.
With newer Infiniti models, Lane Departure Prevention includes a feature that selectively applies the brakes to nudge the vehicle back into position. But the feature needs to be activated after each engine start, and according to the IIHS survey that reduces the effectiveness. According to the survey, 1 in 5 owners didn't even know they had this system, while 1 in 5 owners said they'd never use this feature.
More respondents with Lane Departure Prevention found it annoying (41 percent) than any of the other systems studied. Even though 74 percent reported receiving false or unnecessary warnings from Volvo's BLIS, only two percent found the system annoying. Some pointed to malfunctions or false alarms when the roadway was poorly marked or when driving in harsh weather, but in both cases, the systems can be deactivated with a switch and are temporarily deactivated with the turn signals.
When the IIHS asked respondents if they would want the system again, a surprisingly high percentage said yes. For Volvo's forward collision warning system, 94 percent said that they'd want it again; the lowest number wanted the Infiniti system again, but even then it was a respectable 76 percent.
70 percent thought that they drifted from lanes less often because of the systems, while 64 percent thought they used turn signals more often. With the Volvo system, 13 percent said that they now rely on the system solely instead of turning their head, while with the forward collision system five percent said that they looked away from the road more often.