OVER THE HILLS: A MIDLIFE ESCAPE ACROSS AMERICA BY BICYCLE, by David Lamb, Times Books, 254 pages, $23.

In 1994, international journalist David Lamb got the same unwelcome advice from his physician that has greeted many Americans at midlife: Start taking medication to reduce your cholesterol, stop smoking and cut out alcohol.

Lamb did none of the above. He did, however, complete his plans to bicycle across the American continent from his Alexandria, Va., home to Santa Monica, Calif. He wanted to prove, he writes in this highly readable account of the resulting journey, that “bicycling solo across America is a low-risk, doable challenge” and that “even a middle-aged reprobate with bad habits could have a life.” He succeeds on both counts.

Lamb, a 1962 University of Maine graduate, has received eight Pulitzer Prize nominations for his reporting from Vietnam, Africa, the Middle East, the Persian Gulf and other happening places. Although this book — his fifth — concerns events where Lamb himself is the main character, his comment that “introspection has never been my strong suit” explains much of its appeal. True, Lamb caves in now and then to the temptation to romanticize himself — “movement is a means of expression for those of us who feel at home on the open road” — but it’s his perspective on the world outside, not inside, himself that keeps us turning the pages.

Aside from disclosing his very modest training program before the moment he pedaled out of his back yard and headed West, and sharing a few particulars about his bicycle and gear, Lamb doesn’t clutter his book with specialized details on conditioning or equipment that would make a noncycling reader feel excluded. He’s at his best when he alternates firsthand descriptions of the country he’s riding through with relevant tidbits from an information smorgasbord whose richness reflects his distinguished career of fact gathering — for instance, little-known data about the location of Civil War battlefields, old Indian trails, and why Conestoga wagons may be the reason we now drive on the right-hand side of the road.

The time-honored literary tradition of fingering the pulse of small-town America far from the coastal cities’ frenetic congestion is part of Lamb’s purpose. He’s especially adept at capturing in a few paragraphs the struggles of once-prosperous communities astride former major routes such as U.S. 66 that were bypassed by the interstate system. But he doesn’t stop there. His journey also serves as a moving podium from which to address the reader on The Bicycle and its seldom recognized place in history — as, for instance, a social leveler, an early force in the movement to improve America’s roads, and a vehicle of women’s liberation.

He interjects accounts of his own travails with details about organizations such as the pre-20th century League of American Wheelmen, and about intrepid early cyclists who toured on heavy, less sophisticated bicycles over poor or nonexistent roads. He documents early public hostility to cyclists — their machines frightened the horses — and finds modern counterparts in drivers whose playground-bully instincts activate when they see an adult (especially one wearing cycling garb) on a bicycle.

As much as the bicycle is of the past, Lamb writes, “In an age of waste and extravagance, [it] is of the future.” The bicycle boom of the late 1800s ended with the rise of the automobile, but 100 years later the bicycle re-emerges as efficient, healthful alternative transportation.