The fatality rate in 2001 for motorists between 16 and 20, according to the National Highway Traffic Safety Administration, was more than double that for drivers over 70. The American Association of Retired Persons estimates that drivers 55 and older compose a quarter of the driving population, but have only 18 percent of the accidents. The older the driver, the fewer miles he puts on his car.

As the baby boomers age, the numbers of older drivers will increase. Large majorities of them live in the suburbs or in the countryside without public transportation. Rural and suburban communities must arrange for alternative kinds of transportation for those who are failing in their driving ability; demand can drive public and entrepreneurial innovation.

Preventive remedies for the aging driver abound. Their licenses could be renewed at shorter intervals, with tougher physical tests. At the first signs of diminished alertness, a designated adult in the family should monitor the elderly driver closely for the good of everyone else. They shouldn't drink and drive, but who should? Doctors who prescribe medications for the elderly must make them aware of their influence on driving.

The older citizen who tries to avoid danger is likely to take personal responsibility with considerably more seriousness than a younger person who courts danger through partying and risk.

I like the example of Lord Renton, the 94-year-old "Father of the House of Lords" in London, who volunteered the other day to take his first driving test. He first drove a car in England before 1935, the year a driver's license was first required. He enjoyed a grandfather clause, you might say.

Deciding he owed it to himself and his fellow drivers to submit to a test, he submitted himself to the indignity of taking the test on a small and unfamiliar Ford sedan, not his usual cup of tea. Personal responsibility will out. He succeeded brilliantly. We could expect no less from seniors on this side of the Atlantic.

So let's let Granny drive for as long as she can. Road age is a lot less dangerous than road rage.