The vehicle wasn't out of control, California Highway Patrol Officer John Fransen said, but it was moving erratically. It kept drifting slowly back and forth, from one side of the lane to the other.
"I pulled the driver over because I thought he might be under the influence," Fransen said. "It turned out he was legally blind. He was literally using the reflectors on the roadway and the curb as his guide as to his position in the lane. Too far to the left, he started hearing rumbling. Too far to the right, he'd hit the curb."
The incident is more extreme than most, but it serves as a graphic example of how stubborn some aging seniors can be about giving up their driving privileges.
That topic is one of several addressed in the CHP's "Age Well/Drive Smart" program that recently debuted in Contra Costa County. It's not only about when a person should consider hanging up the car keys but how physical fitness and driving accessories can help older adults remain safe behind the wheel.
"There are some people who can keep driving after they're 100," Fransen said. "If they have all their faculties and are physically OK, they can drive as long as they want."
Volunteer officer Cindy Lima, who moderated the session in Pleasant Hill, said many factors impairing driving ability can be easily remedied.
If your line of vision is not at least 3 inches above the steering wheel, a wedge-seat cushion might be the solution. If a stiff neck prevents you from turning to see blind spots, exercise or massage can help. Another option is convex mirror attachments on side-view mirrors that provide a broader field of vision.
The program introduces more than a dozen accessories designed to compensate for the physical limitations we can all look forward to in the years ahead -- arthritic hands, aching joints, slower reflexes. Aging is such fun.
There also were some safety tips: Avoid peak traffic hours; use less-traveled routes; limit nighttime trips; beware of turns (where 60 percent of accidents happen); and practice the three-second rule. (Observe when the vehicle ahead of you passes a stationary landmark; if you reach it in less than three seconds, you're following too closely.)
And a suggestion for drivers of any age: Prepare an ICE (In Case of Emergency) card for your glove box, indicating whom should be notified if you're incapacitated. That's the first place officers will look.
Inevitably, the presentation turned to the fateful day when a senior who's no longer capable of driving needs to be persuaded of that. Lima said she had that conversation with her father, and it didn't go well. For Fransen, it was his paternal grandmother, who had been involved in several fender-benders and was cited for driving on the wrong side of the road.
"Have an open dialogue and be prepared to present a plan," he said, "so it's not just a matter of giving up driving but explaining what resources they can rely on to get around to shop for groceries, get prescriptions and things like that."
Explain the public transportation alternatives. Enlist friends and relatives to provide rides. Set up a monthly tab with a taxi cab company.
"Once the decision was made and my grandmother realized people would help her out, she actually was happier she wasn't driving," he said.
So was her grandson.
Contact Tom Barnidge at email@example.com.