When Bill Trogdon was a kid in the late 1940s and early '50s, his family would go on vacation during the last two weeks of August.

"Our home in Kansas City was the hub of the wheel, and each year we went up one spoke," he says. "My father liked to get on the highway and travel its length. Driving was therapeutic for him."

They went to Chicago, Minneapolis, Washington, San Francisco, New Orleans -- enough so the young Trogdon got his fill of following the main lines. When he began traveling by himself, he took instead the roads with curves and bumps, and when he did he noticed a quietude that made it easier to see and sense the land.

In 1978, after he lost his job teaching English and split up with his first wife, Trogdon went on a long journey to such places as Brooklyn Bridge, Ky., Nameless, Tenn., Klickitat, Wash., and Ninety Six, S.C. His book about the trip, published under his Sioux name William Least Heat-Moon and called Blue Highways, became an unexpected hit, its popularity fueled by those seeking nostalgia, vicarious experience or simply a manual for their own voyages.

The title came from the old maps, which showed the main highways in red and the back roads in blue. The past fades and colors change, and the Rand-McNally atlas now paints the interstates blue and the minor routes gray and black. Yet the idea of the blue highways remains: a place where you can lose yourself.

"There are more than three million road miles out there, counting gravel roads and everything," says Least Heat-Moon in a voice like a handful of gravel itself. "If you stay off the interstates and away from the national parks this summer, you'll be okay. There's too much country to get jammed up."

There's an old distinction between the two ways of getting anywhere, and he thinks it's still accurate. "A tourist is a person to whom the ends are the most important -- to reach a goal, like Yellowstone, by a set time. A traveler is after the means -- they go at a slower pace and enter into the lives of people they meet. It's a case of sightseers versus people-seers."

It's not as easy as blue highways being good and interstates bad. Both serve their function. It's just harder to see the country from the interstate because of the speed you're traveling at.

"But when you drive the blue highways you're looking at people's front yards, into their houses and their barns. When you're going through Tottenville and have to slow down to 20 miles an hour, the temptation is to pull off and stretch your legs."

Along the blue highways, life continues without the self-consciousness of the big cities. "To go in a town like Dime Box, Texas, to sit in the tavern, walk on the main street, is like watching an anthill without the ants knowing. If you're there a couple of days, you become part of it."

Good traveling is the art of paying attention, and the hardest requirement is to do it alone. John Steinbeck's Travels With Charley, Least Heat-Moon notes, "is a delightful book, but he had to travel with that damn dog. To read the book is to know more about Charley than the people of America. And if traveling with a dog can do it, traveling with another human being is an even greater demand on your concentration."

Perhaps. But Least Heat-Moon is traveling this summer with his wife, Linda, "just poking along and looking into things." He's been within 50 miles of any given point in the lower 48, except the corner where southeastern Oregon and northwestern Nevada meet. It's a gap he aims to eliminate.

"I've got no schedule," he says. "My favorite kind of trip is where there's only one single reason for traveling some place. Then, before you get there and do it, all sorts of other things can happen."