Many older adults might be driving under the influence without even knowing it. Common drugs—from painkillers to beta-blockers—can impair driving abilities by causing dizziness, sleepiness and even disorientation. But seniors, who are more likely to take them, are rarely aware of the risk, according to a recent report [pdf] by the AAA Foundation for Traffic Safety (and highlighted today by the Wall Street Journal).

Of the 630 55-plus individuals surveyed—92 percent of whom still drove—about 69 percent were taking at least one prescription medication that could impair their driving, but more than 80 percent had not been warned about the possible impact of these drugs on driving. And of those who were taking five or more of these potentially impairing drugs (about 10 percent of the respondents), only about 22 percent had "some awareness" of the side effects, leaving the rest in the dark when they got behind the wheel.

Giving Alzheimer's patients a battery of cognitive tests may help predict whether it's safe for them (and us) to get behind the wheel, according to a new study.

"We found that tests that involved visual perception and visual memory were particularly important in preventing driving errors," says Jeffrey Dawson, a biostatistician at the University of Iowa College of Public Health in Iowa City and lead author of the study published in Neurology.

Dawson hopes the findings will pave the way for the creation of a test that physicians could give to people diagnosed with Alzheimer's to determine if it’s safe for them to be on the road.

Parents worried about teens' safety (not to mention the safety of everyone else on the road) when they take the new car for a spin will soon be able to control how fast the kids drive and how loudly they crank up the tunes. They will also be able to remotely nag  their young drivers to wear their seatbelts, all thanks to a new technology called MyKey that Ford Motor Company plans to introduce as standard equipment on its 2010 Focus coupe and, down the road, in its Ford, Lincoln and Mercury models.

MyKey has a transponder chip that, once plugged into the ignition, allows car owners to program their car's computer. This includes setting the car's maximum speed limit as high as 80 miles per hour, and to issue warning chimes when the car's speed reaches 45, 55 or 65 miles per hour. Although a driver can still do a lot of damage at 80 miles per hour, and it exceeds most speed limits, this speed does allow for more maneuverability during highway driving (particularly if a driver needs to pass the car ahead). The MyKey can also program the car to chime a six-second seatbelt reminder every minute for five minutes and, after that, to mute the car stereo until the driver buckles up. Plus, MyKey can program the stereo to keep it down to no more than 40 percent of full volume.

Hey drivers, here's a thought: How about keeping your eyes (and ears) on the road instead of on your cell phone? Just have to chat or text message while driving? Then steer clear of California. It's already illegal to make calls on hand-held mobiles there, and now Gov. Arnold Schwarzenegger has signed a bill into law that prohibits people from reading, writing or sending messages over wireless electronic devices while operating motor vehicles.  The measure, state Senate Bill 28, takes effect Jan. 1.

First-time offenders will face a $20 fine; subsequent violations are $50 a pop.

The new law comes on the heels of the ban on using hand-held cell phones while driving, which took effect July 1. Both measures were sponsored by Democratic State Sen. Joe Simitian of Palo Alto.