New York

LAST autumn, I had to take the car keys away from an elderly relative who lives alone. This intervention should have happened much earlier but when the day came, it was one of the more emotionally wrenching things that I have ever done. "Don't take my car away," he pleaded.

"Without my car, I don't have a life." The fear he expressed is one shared by many older Americans, who, overwhelmingly, live in places where car travel is a necessity. And that number is skyrocketing: The population aged 65 and over is expected to grow to 79 million from 48 million in the next 20 years, and by 2035, one in three American households will be headed by someone 65 or older (and 9.3 million of those will be one-person households like my relative's).