By JOAN LOWY
WASHINGTON (AP) - Baby boomers started driving at a young age and became more mobile than any generation before or since. They practically invented the two-car family and escalated traffic congestion when women began commuting to work. Now, 8,000 of them are turning 65 every day, and those retirements could once again reshape the nation's transportation.
How long those 74 million people born between 1946 and 1964 continue to work, whether they choose to live in their suburban houses after their children leave home or whether they flock to city neighborhoods where they are less likely to need a car will have important ramifications for all Americans.
If boomers stop commuting in large numbers, will rush hours ease? As age erodes their driving skills, will there be a greater demand for more public transportation, new business models that cater to the home-bound or automated cars that drive themselves?
It was the boomers who made "his" and "hers" cars the norm when they started building families and helped spread a housing explosion to the fringes of the nation's suburbs. Traffic grew when boomer women started driving to work like their husbands and fathers. With dual-earner families came an outsourcing of the traditional style of life at home, leading to the emergence of daycare, the habit of eating out more often and the appearance of more and more cars and SUVs.
This generation "has been the major driver of overall growth in travel in the United States and that has had a tremendous impact over the past 40 years in how we have approached transportation planning," said Jana Lynott, co-author of a new report by the AARP Public Policy Institute, an advocacy group for older Americans, on how boomers have affected travel in the U.S.
The report is an analysis of national surveys by the Federal Highway Administration of Americans' travel patterns since 1977. The most recent survey, conducted in 2009, included over 300,000 people in 150,000 households.
As a result of changes over the last four decades, driven in part by baby boomers, the number of vehicles in the U.S. has nearly tripled, the report said, and total miles traveled has grown at more than twice the rate of population growth.
Since 1977, travel for household maintenance trips _ a category that includes doctors' appointments, grocery shopping, dry cleaning and the like _ has grown fivefold. The average household ate out once a week in 1977. By 2009, the average household was eating out or getting meals to take home four times a week.
But what really caught transportation planners flat-footed was the soaring growth in traffic congestion in the 1980s after large numbers of women started commuting alone in their cars, said Nancy McGuckin, a travel behavior analyst and co-author of the AARP report.
Highway engineers, who hadn't anticipated the consequences of the women's movement and dual-earner families, had just finished building the interstate highway system only to find it insufficient to meet the demands of the new commuters, she said.
Now that boomers are beginning to move into a new phase of life, their travel patterns and needs are expected to change as well.
People tend to travel the most between the ages of 45 and 55, but taper off after that. "With this immense slug of the population sliding off their peak driving years, we would have to expect total travel might go down a bit," said Alan Pisarski, author of the Transportation Research Board's comprehensive Commuting in America reports on travel trends.
If millions of baby boomers start driving less, it would reduce gas tax revenues, which is used to help states maintain highways, subsidize public transit and fund other transportation repairs and improvements. Federal gas tax revenue is already forecast to decline as mandatory auto fuel economy improvements kick in.
There are signs boomers may already be slowing down. The rate of growth in travel in the U.S. began slowing in 2006. Actual miles traveled dropped sharply during the 2008 recession and now appear to have leveled off.
But boomers could defy expectations again by remaining more mobile into their retirement years than past generations.
"It doesn't matter whether they were in their 20s and 30s or approaching retirement, they are still traveling more than those who came before them or those who came after them," Lynott said of boomers.
Most boomers live in the suburbs and are expected to remain in the homes where they raised their children even after they become empty nesters. The housing bust has also trapped many older boomers in large homes whose values have fallen, sometimes below the balance of their mortgages.