DETROIT — John Villa laughs about it now — the "conspiracy" last year to take away his car keys, he calls it.
"I was a little incensed," said the 96-year-old former manufacturing manager.
The conversation wasn't easy for his children either.
"We were very cognizant of the fact — and this is important — that if he lost his ability to drive, this would seriously affect his independence and his sense of self," said daughter Nancy Villa Bryk, an Eastern Michigan University professor.
"It was a very difficult conversation, and he found it profoundly upsetting, which was upsetting to me," she said.
Analyzed by miles traveled, the risk of being involved in a fatal crash begins climbing at age 75 and increases notably after age 80 — a result of increasingly frail bodies and medical complications from injuries.
And though older drivers are less likely to get into accidents overall, in part because they limit their driving to familiar roads and safer times of the day, research suggests they have a tougher time making left turns at intersections, for example.
But for many families, the question of "Is it time to park the car for the last time?" is rarely answered by a medical problem or serious accident.
Rather, it's the little, insidious failings of the aging body that chip away at our ability to drive and trigger those nagging worries from loved ones.
"It creeps up on you," said Dr. Pratik Bhattacharya, a neurologist for Detroit Medical Center's Sinai Grace Hospital and an assistant professor at Wayne State University.
Cataracts and other eye problems mean nighttime glare. Arthritis makes it difficult to grip the wheel or twist your torso to check different directions. Nerve damage dulls the senses, making it more difficult to apply the proper pressure on gas and brake pedals or to make the switch between pedals quickly.