In its relentless way, the sign above the Friendship Heights bank kept flashing: 7:38 a.m. and 36 degrees. And in his relentless way, Paul S. Green kept striding, never looking up. Green is a walker, and on this day, he was a frustrated one.

"Usually, it's just about an hour to right here," he said, sidestepping and idling bus and putting a halfback-like feint on a slow-moving woman in front of him. "I can tell we're late today. I can just tell."

To Paul Green, walking is serious business, which means that reaching Wisconsin and Western avenues eight minutes behind schedule borders on a felony. But he fears that the alternative, to drive like most of his fellow commuters, would amount to a death sentence. "At my age (63)," he said, grinning ruefully but never breaking stride, "I read the obits."

Paul Green has walked to work nearly every weekday for the last 15 years. And for him, it isn't just some saunter in the park. He lives on Johnson Avenue in Bethesda, about three-quarters of a mile inside the Beltway, exactly 9.9 miles and about 2 1/4 walking hours from his public relations job at the Committee on the Present Danger's Dupont Circle offices.

Some days, his wife drives him to Chevy Chase Circle on the way to her job, which reduces Green's one-way walking distance to four[words illegible]

According to a Metropolitan Washington Council of Governments study, and interviews with several Washington-area transportation planners, there are other Paul Greens, but not many. About 70,000 Washington-area workers cover a significant part of their journeys to work on foot. Only about 8,000 of those consistently walk more than two miles one way

Walking considerable distances to work was much more common here 20 years ago, when far more of the Washington-based government work force lived in the District or in Arlington County, within a few left-right-lefts of the federal offices in Southwest. Today, it seems, if the love affair with the car hasn't ended the resolve to walk, the subway or the bus has.

To be sure, Paul Green will jump on a bus if the weather suddenly turns wet, and he will take a pass for a day if he will need the car immediately after work. The rest of the time, however, the major decision of his morning is whether to wear his brown rubber-soled shoes or his black ones, depending on the color of his suit.

In perhaps 3,000 sorties down his unchanging route of Johnson Avenue, Greentree Road, Old Georgetown Road, Wisconsin Avenue, Military Road and Connecticut Avenue, Green has had dozens of near-crashes with motorists who believe in WALK and DON'T WALK signs (Green doesn't).

Once he was splashed from head to foot on the Taft Bridge by a passing car ("Did you ever see "The Poseidon Adventure"? It was like the tidal wave in the movie. Whoosh! Covered me."). Once he had a moveable 15-minute conversational feast with a woman construction worker who was helping to build the new campus of the University of the District of Columbia -- and who fell into step with Green as he passed by so she could tell him her life's story.

Green says he has never been mugged, seriously injured in a fall, gotten blisters, been bitten by a dog or pushed himself to the point of breathlessness. So purposeful is this trim, steel-gray-haired native of Brooklyn that when he sometimes runs into friend of his two daughters, he only stops to talk for a second. "I can't stand to stop once I start," explained Green of his limited attention span. Indeed, this fellow is such an expert at the duration of WALK and DON'T WALK cycles that he knows exactly when he must start sprinting to beat the cross-traffic.

Green's 4.5-mile-per-hour pace is much faster than the average stroll, a lesson this reporter learned quite painfully when he examined what used to be his feet the morning after trekking the entire route with the master walker. And the relentless pace has carrried over to all aspects of Green's life. "I spend a lot of my life half a step ahead of guys I work with," he said. "People are always saying, 'Hey, slow down, will you?'"

As Green goes, he thinks about more than going.

Often, he writes poetry or business letters in his head. (Last week, he composed an interview request to Nancy Reagan between Nebraska Avenue and Calvert Street, which he copied down once he got to work). Occasionally, he confects elaborate dreams of glory ("Walker Mitty stuff"). Always, he directs silent pity at the bundled hordes waiting for buses ("Look at all these healthy young men. Terrible!").

And once in a while, Green will spread his arms, palms down, and imagine himself to be what he calls the poor man's hang glider. "On a windy day," he said, "it really lifts you." He said it also draws astonished gazes from his audience of bus-awaiters. "But if I worried about what people thought of this, I'd have given it up a long time ago."

Paul Green got the walking habit when he came to Washington in 1939 as a graduate student in journalism. "The guys covering the Hill used to walk back to the [National] Press Building [a little over a mile west] all the time," he recalled. "They got me started. I've made that walk thousands of times."

As the years went on, however, Green was seduced by free parking spaces that came attached to staff jobs on Capitol Hill and the U.S. Department of Transportation. "I drove because I could," he said. Fifteen years ago, a friend's nagging finally got him. "I realized that all I was doing in the morning was reading the paper. I tried walking, and I discovered I liked it, and it was good for me. You can't beat that."

Green always underdresses for his constitutionals ("You do sweat doing this, you know."), and he always stops for calls of nature at one of four widely spaced motels. "I don't think I've ever said a word to anyone in any of them," Green said. "I just know they have lovely bathrooms."

His satisfactions are three:

Sunrises ("I've seen hundreds. They never cease to delight me.").

Watching friends in Oldsmobiles pass him ("I always think, 'You should be out here, too.'").

And hearing people say they know they should be joining him, but just don't have time.

"I don't have time, either," says Green, as he shoulders through the crowds in front of the Washington Hilton, five minutes from the end of yet another trek. "I just find it."