Driven a new car lately? Let's go for a ride. Backing out, the car beeps to warn a pedestrian walking by. A dashboard light illuminates if the vehicle ahead is too close. A side mirror light flashes, signaling a truck behind you in the blind spot — not a good moment to pass. And if the car senses you're drowsy or driving erratically, a chime sounds an alert.

See also: How to build a better car for boomers.

New technology in smart cars is sometimes dangerous and distracting for older drivers. — Illustration by Hal Mayforth

Resembling computers on wheels, many of the latest vehicles are loaded with sensors, lasers, cameras and crash warning systems that alert drivers to blind spots and impending collisions — or when they're drifting too far out of their lane. If the driver fails to respond, some models assume control and apply the brakes. Other options assist with the pesky chore of parallel parking or maintain a safe distance between vehicles.

The aim of all the bells and whistles is, of course, safety. Such gee-whiz technology could protect older drivers, whose most common accident is failure to yield in an intersection, according to the Insurance Institute for Highway Safety (IIHS). Reaction time slows and vision changes with age. Drivers over age 70 may misjudge the speed of an oncoming car, and those age 80 and older may fail to see the other vehicle at all. So these warning devices could indeed save lives.

But how much is too much? Could older drivers, whose adaptation to new technology may take a little longer, be more at risk from the very safety features meant to protect them? The federal government, the auto industry and the research community are debating the potential for driver distraction from too many chimes, beeps, computerized voices, vibrating steering wheels and lights flashing on dashboards, windshields or side mirrors.

"If a three-inch light on your dashboard illuminates because you're too close to the car in front, you may look down at the dashboard first," says Bryan Reimer, a research scientist who studies human-machine interface at the Massachusetts Institute of Technology (MIT) AgeLab.

Dick Myrick understands how easily attention can waver. As a participant in a mid-2009 MIT study on driver distraction, he drove an SUV on major interstate highways while wired to an EKG machine that monitored his heart rate. In an exercise designed to mimic distraction, he was asked to recall numbers in a sequence, then punch them into a keypad or say them aloud. "It was distracting and very stressful," says Myrick, 62, a retired engineer from Arlington, Mass. "My heart rate went up."

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