"You know, you're sitting up there at the console, and the red lights and the green lights are flashing, and the train is hitting 75 miles an hour and whoosh, down you go into the river tunnel. There's such a thrill in it!"

James Davis is fascinated by Metro. His out-of-town visitors are given guided subway tours. Waving his Metro flag, he makes every station opening. And when he and his wife of 22 years recently celebrated their anniversary, he squired her to lunch via Metro.

But unlike the passengers who sit in back, swaying slightly in the cushioned cars snaking around darkened curves, Davis gets to sit up front, right where, he says, the action is.

Like an orderly smoothing out the tucked corners of a hospital bed, Davis eases the last few working trains into the National Airport station and docks them for the night. As the night supervisor there, he gives them safety checks and readies them for the morning rush hour. When the New Carrollton line opens, Davis will move to the day shift as a train operator, driving the cars from Virginia into the Maryland suburbs on the Orange line.

A 17-year veteran of everything from traffic jams and Metrobus breakdowns, confused customers and, most recently, out-of-service farecard machines, Davis has been making the transition with Metro from bus to rail. He was first a bus driver, then a rail station attendant and, finally, a train operator. And in an era when gripes about the job are as numerous as the cups of coffee it takes to keep doing it, Davis is an anomaly. He loves what he does, and, he said recently, he always has.

A low-key, soft-spoken man of 44, Davis is sitting in the new Washington Metropolitan Area Transit Authority Building at 6th and F streets NW. His brown Metro tie and shirt are neatly in place, and he doesn't look like a man who just got off the late shift - 10:30 p.m. to 7 a.m. - an hour ago.

Trains have been his primary interest since he was a kid in Pittsburgh, Davis explains, when he used to watch the trains near his house. Although he learned the plasterer's trade as a youth, he took a job as a street car driver in his home town after he left the Army in the '50s.

"You know, I just like people," Davis said, "and there's nothing like a street car for getting people to talking."

For most people, riding the bus, train or subway is simply a way to get from here to there, from job to home, from work to shop. To many riders accustomed to the bleak and tiresome commutes, driving a Metro bus or subway may seem to be one of the most boring jobs imaginable, a job whose subtle headaches and small triumphs are lost in the seemingly endless rides.

But to Davis, that yellow light he just passed through is a success over the many red lights to follow, and the woman fumbling for the token she dropped on the stairs is to be cajoled, not scolded. For him, each day is an adventure.

"I used to drive the No. 40 bus," he said, "and the time would always go fast. It became a game to see what lights you could catch, which you would always miss, how to increase your time, what streets to go down to avoid traffic jams.

"I never had any problems. I was just trying to get those people to where they were going."

But when Davis heard about the Metro subway, he remembered the joys of his days at the helm of the street car, and, "The day they broke ground I started to figure out some way to get on it."

Metro had a list "a mile long," Davis said. But he sent in his application - "three or four of them so they wouldn't forget me."

His quest was successful and he became a station attendant at one of the first Metro stops, Farragut North. Later, he moved to Judiciary Square.

Eighteen months ago, he began his subway operator training. After completing the class schedule at the Brentwood Shop classroom and at WMATA headquarters, Davis joined the ranks of the 135 other drivers.

"You know, they can really run the trains without us, but they don't think the people would like that too much. People want to hear the operator's voice at the stations, just to know he's there.

"First, you have to learn to operate the train manually. Gradually, you let the machine take over and the computer is telling the train what to do all the time. But you have to watch to see that the machine is doing what it is told. If not, you have to ask for permission to take control."

When a train begins to suddenly jerk along in the tunnel, Davis said, that usually means there is a problem somewhere along the line and the driver is operating the train and controlling the speed and braking mechanisms himself, jobs normally done by computer.

The "hands off" policy for the driver and his isolation in the cab leads to some lonely times, Davis admits. Those are the times, he said, when he thinks about his two children and grandchild, his wife and their plans to own a "dream house" some day.

"But it can be such a smooth job - no lights, no traffic, no pressure.

"Think of it. You have one man hauling so many passengers. I thought I was doing a marvelous job in carrying 50 on a bus, but now I've got 1,000 people behind me. It makes me feel pretty good."