It's a tough decision everyone will have to make one day: at what age does it become too unsafe to get behind the wheel of a car? Bob and his wife Bonnie feel that this time has come for his elderly mother Mary. "She's 89-years-old and has macular degeneration," explains Bonnie. "She's only been in one accident ... that she admits to." Mary contends those were just small bumps and taps, and that she'll know when she can't drive anymore. She dreads losing her independence once she turns over the keys. "I don't want to be a burden to anybody," she says.

How do you take away the car keys without hurting the one you love, but you know that if you don't, others may be hurt? To help answer this question, Rachael calls in Sue Ferguson, a consultant on senior driving issues. "The big concern we have," Sue says, "is that as we get older, we get so much more fragile. For every mile we drive at age 85, we're about ten times more likely to be in a fatal crash than even at age 60."

While age might be a determining factor in one's ability to drive, everyone is different, so Sue suggests taking the following steps:

• Observe their driving. "Go out with them to the drug store or the grocery store and see whether they're noticing or attending to stop signs, or if they are yielding to other drivers when necessary. Take a ride with them."

• Observe their vehicle. "If they've been in an accident recently, even if it might not be their fault, that may be a red flag and you should take a closer look. If you look at their vehicle and it has all these unexplained dents all over it, then that's another sign."

• Observe them. "If you notice that they are confused or agitated or forgetful, or they're having trouble following directions, that's another sign that could translate into driving difficulties."

Rach asks what you should do if you start noticing the above signs. "The first thing you do is sit down with them," Sue says, "and share your concerns about their driving and about their safety, because if they get in a crash, they really are more likely to die. And talk to them about the things that they want to continue doing -- what are the activities that they would really miss? Make sure you work out a plan so that they can get there." Sue suggests calling your area office on aging which will have lots of information for older people in your community.

Sue says that if you are convinced your loved one shouldn't be driving but they refuse to give up their keys, consider writing to your state's Department of Motor Vehicles. She says, "All of them will accept letters if you explain your concerns. They'll bring them in for an interview and reassess and be fair. Maybe they won't take away the license, or maybe they'll just put a restriction on it -- but they can decide."

After some careful thought -- and a few tears on her daughter-in-law's part -- Mary decides to hand over her keys. But as soon as she does, Rachael tells her that she handed them over to the wrong person. Instead, Rach tells Mary to hand them to the handsome man next to her, who will be her new driver! Courtesy of We Drive U, Mary will have 100 hours of free chaffeur service anywhere she wants to go, much to her son and daughter-in-law's relief.

Can you relate to Mary and Bonnie's story? Know someone who shouldn't be driving, but it's too hard to take away the keys? Join the discussion here.