Here's more data from the National Highway Transportation Survey just released last month.
The difference in driving habits between young adults and those over age 40 is dramatic. Last year those 40 and over were just 46.4% of the population but they drove a whopping 59.3% of the miles.
For example, a typical 58 year old last year drove 11,607 miles, while the average 28 year old drove just 7,011 miles last year.
But all the government surveys indicate that after age 65, people start to drive less. In ten years most of the Baby Boomer generation will be over age 65. The squeeze will be on for highways, as driving drops even more.