Gas prices may have risen steadily all year, but Steve David's 40-mile round-trip commute from Randallstown to downtown Baltimore has only been getting cheaper.

For the past year, the 45-year-old physical therapist has been traveling to his Mount Vernon office atop a two-wheeled electric chariot powered by a two-horsepower engine.

The Segway has been on the market for more than six years. And while police and security officers can be easily spotted cruising along on the scooters, Segway commuters remain a rare sight. Especially ones who go from suburb to city.

"Some mornings it's a little chilly, but it's relaxing," said David, who grew up in Baltimore after emigrating with his mother from Trinidad three decades ago. "Even the days when it rains I've used it."

David's wife, Kristi, and their three sons surprised David with the $5,000 Segway on his birthday last May after enduring weeks of his not-so-subtle hints, such as repeatedly leaving the computer logged on to Segway's home page.

David wanted the device because he could no longer bear burning gas by driving downtown. He began taking the subway, but driving his car to the Owings Mills Metro station seemed like a waste.

The Segway is "pricey in the initial outlay, but it's much cheaper than a car, including operation and management," David said. At the time his wife bought it, "gas prices were inching up and I worked downtown. I figured it would be a good way to get into town and to get around town without looking for parking."

On a typical morning, David's Segway is plugged into an outlet in the kitchen just like the toaster, refrigerator and other appliances. He packs food and other items into a bag hanging from the handlebar rising from a U-shaped platform held aloft by two wheels. He steps on and leans forward to start rolling along his hallway, steering right out the front door.

He zips along neighborhood streets and busy roads, waving at familiar faces and curious onlookers alike. As traffic near the Owings Mills subway stop races by or comes to a standstill, David maintains the same steady pace, the picture of perfect posture as he leans forward. It takes him 20 to 30 minutes to get to the station.

A 2002 state law devised specifically for the Segway does not allow David to go faster than 15 mph, but there is no worry of a speeding ticket because the device does not exceed 12.5 mph. The Maryland General Assembly, like many other states, passed rules six years ago that equated the Segway to a pedestrian rather than a vehicle.

According to Maryland law, he must ride on the sidewalk if there is one, and he is not allowed on roads with speed limits higher than 30 mph. Riders are not allowed to listen to music with earplugs in both ears, which is why David often listens through one ear.

His wife has worried that he might be hit by a car or run into a pedestrian because the Segway is so quiet. But she has another reason to worry: Her husband's first test run of a Segway at a downtown rental office resulted in a lost leg - of a mannequin.

"My husband ran it over," she said. "By the time he finished with the dummy, it didn't have a leg."

David said he has only fallen off the device once, when he hit an unexpected bump.

Dick Segar, owner of Segway of Annapolis, the only dealer in the state, said accidents are rare.

"You're no more exposed to accidents than any pedestrian would be," Segar said. "Probably less, since you're taller and more visible."

But he added that he believes the extra height warrants the use of a helmet. Segar has scraped his head on a street sign, tree branches and the tops of doorways.

Segar said he has recently seen more people inquiring about buying a Segway to commute to work, especially people who live in cities.

A Segway Inc. spokeswoman said some large dealers across the nation have seen 20 percent to 50 percent sales increases in the last year due to gas prices. Segar, whose core customers are companies and government agencies, said he has seen a surge of interest from commuters.

"Just this year alone, the inquiries and sales for commuting purposes have increased dramatically because of gas prices," he said.

Two years ago, he sold one Segway to a Washington commuter. In the past six weeks, he said, he has sold four for commuting purposes and one to a student who wanted to use it to get around at college.

"They've given up the second car, the parking spot," Segar said. "And they've gotten some good foul weather gear."

David rides his Segway about five miles to the subway stop and never steps off to take the elevator up to the train platform. He gets off at the State Center subway stop near downtown and travels the last mile to St. Paul and Biddle streets by Segway, cruising along the sidewalks outside the Meyerhoff Symphony.

Recently, a Maryland Transit Administration officer told him he had to walk the Segway to the tracks. Other days, David says he is allowed to ride it anywhere.

David's desire to preserve the environment has guaranteed that at least one other person will do the same: his son, Turrel. Like most 15-year-olds, the Chesapeake High School student is obsessed with cars. But his obsession centers on an electric car called the Aptera, which he wants to buy. He said his father has inspired him to be more "green."

"To show enough initiative to care about your planet enough to go out and buy something that will not use gas and deplete oxygen - that's what makes my dad so cool," he said.

doug.donovan@baltsun.com