Preston Carter, 100 year old driver, injures 11 in Los Angeles accident.

A driver who will be 101 in September backed out of a parking lot near an elementary school in Los Angeles, plowing into 11 people, including nine children. Fortunately no one died as a result of the incident on Wednesday, but it highlights the challenge that aging drivers and their families face in deciding when it's time to get off the road.

Although they only account for about 9 percent of the population, National Highway Traffic Safety Administration statistics show senior drivers account for 14 percent of all traffic fatalities and 17 percent of all pedestrian fatalities.

A recent report by Carnegie Mellon University in Pittsburgh and the AAA Foundation for Traffic Safety found the rate of deaths involving drivers 75 to 84 is about three per million miles driven - on par with teen drivers. Once they pass age 85, vehicular fatality rates jump to nearly four times that of teens.

Richard Nix, executive director of Agingcare.com, says many senior drivers don't realize their eyesight, hearing and reflexes aren't as sharp as they used to be. They may be taking medication that impairs judgment, memory or coordination or suffer from arthritis or Alzheimer's. Consequently they may not realize it when they blow past a stop sign, forget to signal a right turn or confuse the gas pedal with the brake.

Even when they admit to themselves that their driving skills may not be up to par, some older drivers are still reluctant to hand over their keys. According to Nix, loss of driving privileges is a difficult and emotional issue for many.

"People have been driving their whole life and have trouble believing they're incapable of continuing," he said. "They feel like their independence has been taken away."

And Nix points out, it's frequently a difficult subject for loved ones to face as well. They may feel a pang of fear every time their elderly parent gets behind the wheel but are reluctant to confront them for fear of hurting their feelings are starting a battle.

Nix says that if need be enlist the help of other family members, friends or their physician when a loved one presents a danger on the road. In some cases, it may even be appropriate to take legal action, though laws vary from state to state.

Whether an elderly driver comes to the conclusion on their own that it's time to surrender their license or they're forced to do so, it's a big moment and it can be devastating. But the consequences of not doing so may be even more devastating.

Consider the case of George Russell Weller, an 86-year-old Los Angeles driver who suffered from arthritis, nausea as a side-effect of medication, and reduced mobility from a hip replacement. Weller's car struck another car then accelerated around a road closure sign, crashed through wooden sawhorses, and plowed through a busy marketplace crowd, killing 10 people and injuring another 63. Weller told investigators he had accidentally placed his foot on the accelerator pedal instead of the brake.

Agingcare.com offers the following advice for senior drivers to evaluate when it's time to stop driving:

• Conditions like cataracts and glaucoma can diminish sight and hamper driving ability. An eye doctor can help establish whether your sight is good enough to drive safely.
• Many older drivers no longer have the strength or dexterity to handle a car. They may shrink in height so much they can no longer see over the windshield. This is especially true for seniors who do little or no physical activity.
• Alzheimer's can impair memory and judgment. Diabetics risk falling into a coma while driving. Even if you have long periods of time when health issues cause no problems, why risk it?
• Medications, especially multiple medications, can greatly impair driving ability. Your doctor should advise you of the dangers your medications present while driving.
• If the minor fender-benders are adding up or you simply feel less confident about driving, it's OK to admit it to yourself that your driving days are over.