Many seniors reduce their driving voluntarily as their abilities decline, but many unknowingly become unsafe to themselves and other motorists. Wrestling the keys from an older parent's hands can be a difficult, though important, chore. The trick is know when and how to do it.

For instance, "Tracy" is trying to get her 86-year-old father to stop driving after he's been experiencing some memory loss and confusion. However, it's been an uphill battle and causing a strain on their relationship. He is angry and feels that Tracy is trying to control him. She is nervous that he may get into an accident or worse.

On the other hand, 87-year-old Cliff Orman saw little clues in his driving that alerted him it was time to stop. One day his car ended up under the back end of a Ford F-250, with some of the truck's tire marking his fender. Luckily, everyone was fine and there was no major damage. His wife Evelyn was already looking into transportation options, which helped ease the inevitable transition.

Giving up the car is not easy to do. This painful action reflects aging, diminished ability, and the loss of freedom.

Julie Lee Vice President and National Director of AARP Driver Safety says families should discuss what are they going to do before it becomes a problem and what transportation is going to be available in their community. "The key is to continue to have these conversations, so there is not a big surprise when it's time to hang up the keys."

The AAA website has a self-rating tool to help assess their skills and get advice on how to maximize their safety on the road. Family members can get advice through a free online seminar on the AARP website.

If you need to assess a senior's driving ability, watch for these red flags:

• Slow response times.
  
• Inability to fully turn to check blind spots.
  
• Running stop signs.
  
• Motorists honking at them frequently.
  
• A hesitation or reluctance to drive.
  
• Cognitive dysfunction, such as getting lost or calling for help.
  
• Repeat fender benders, dings, or paint scrapes on the car.

If you think the situation is serious, consult the person's doctor. Keep in mind that medications and physical conditions, such as reduced vision, a stroke, dementia, and Alzheimer's disease, can affect driving performance in dramatic or subtle ways.

Whatever the cause for the diminished driving ability, family members owe it to their parents and grandparents to watch out for their safety, as well as that of the community.

For more on the issues with teens and older drivers, see our report on "Risky drivers."