BALTIMORE — If you are traveling the roads of western Howard County, Md., some pleasant morning, there's a chance you'll spot a bicyclist who seems to be going rather fast for the amount of exertion he's putting into his pedaling.

Meet Daniel Rowell, an intrepid commuter who regularly makes the roughly 22-mile journey from his North Laurel, Md., home to his Sykesville, Md., workplace aboard his $8,000 Optibike — a hybrid electric bicycle that supplements pedal power with a battery-driven engine.

Rowell is one of a small band of long-distance commuters who regularly leave cars at home and hop aboard electric bikes. It's a choice that draws scorn from some bicyclists though it is almost as effective in reducing carbon emissions.

"The purists don't like it," he said. "They think you're cheating. I tell them I'm not in a race."

Electric bikes are still a novelty in the United States, with a few hundred thousand on the streets and their numbers "poking along," said Frank Jamerson, a spokesman for the Light Electric Vehicle Association. In Asia, he said, there are more than 120 million electric bikes on the road, and they are selling in Europe at a rate of 1 million a year.

"The only thing that will change America is when gasoline goes to $10 a gallon," he said.

Under Maryland law, electric bikes face a combination of regulations. They're classified as mopeds and must follow the same rules of the road as bicycles, said Motor Vehicle Administration spokeswoman Karen Coyle. But unlike conventional bicyclists, their adult operators are required to carry a driver's license, while those younger than 16 need a moped permit, Coyle said.

Rowell, a 46-year-old father of five, says riding the hybrid bike lets him combine commuting with exercise — but not so much that he shows up at the office sweaty and exhausted. Meanwhile, he figures he's saving about $2,000 a year on gasoline and auto maintenance.

"I do it more for the idea behind it. It's a new technology. It's a fun technology," he said.

He estimates that it takes about an hour to bike each way to his job as an electrical engineer with Northrop Grumman — a commute that takes about a half-hour by car. Top speed on a flat stretch of road with full battery power is about 34 mph, though the average cruising speed is 25 mph to 30 mph and can drop to 10 mph to 12 mph going up a steep hill.

With a new lithium battery, the bike can go about 40 miles without recharging, but after two years of depletion, it now powers him for about 33 miles, Rowell said. When he gets to work, he lets it recharge for the ride home. He said his employer is so supportive, it installed an outlet near the company bike rack.

A light rain won't keep him off the road, Rowell said, though he carefully checks the weather radar before leaving work to avoid storm cells. He leaves the bike home in winter, so in a few weeks, he expects to take a break until mid-March. In all, he said, he's probably made 150 one-way commuting trips this year.

Rowell said he's been commuting by electric bike since 2006, starting with a model bought on eBay for $700. Two years ago, he traded up to the Optibike — made by a Colorado company that bills itself as the Ferrari of the electric bike industry. He said the Optibike is more powerful than his previous bike, reaches a higher speed and holds a charge longer.

If he wants to get to work as fast as possible, Rowell said, he'll use busy Route 32 north of Clarksville, Md. For a more pleasant ride he uses a combination of country roads through the rolling hills of western Howard County.

One recent morning, Rowell turned over his bike to a reporter for the five-mile leg of his commute between Highland and Dayton along Highland and Ten Oaks roads. Any concern that the ride would be so motorized it would provide no exercise was soon dispelled. The bike is engineered to encourage the rider to pedal, though there is no need to stand to power the vehicle up steep hills. Even an out-of-shape novice was able to reach speeds as high as 27 mph, though the average was closer to 18 mph to 20 mph, and get a moderate workout in the process.

Craig Taber, marketing director for Optibike, said the bike is designed to deliver exercise as well as transportation.

"You're encouraged to pedal all the time," he said. "You're pedaling the same as a regular bike, only going a lot faster."

Taber said the Boulder-based company has sold about 600 bikes since it was founded in 2005 — operating out of a garage until it moved into its current manufacturing facility. But he said Optibike believes it can ramp up its production 10-fold over the next year to 18 months without sacrificing the quality that fetches prices from $6,000 to $13,000 per bike — all sold directly by the company and not through a dealer network.

Taber said more than half the company's customers are long-distance commuters who appreciate the technological strides made in electric bikes in recent years.

"We actually designed the bike for people like Dan," Taber said. "What Dan's doing wouldn't have been possible four years ago."

Rowell now serves as the Maryland "ambassador" for the company, and would receive a commission if his demonstration of the product led to a sale. He says he hasn't collected any money yet.

Taber said a significant number of its customers are couples who want to ride together for recreation but who are not equally athletic. He said the company has some celebrity customers, notably Dallas Cowboys DeMarcus Ware, who uses it as part of his conditioning program.

Riding an electric bike — even one as expensive as the Optibike — is still looked down upon by some bicyclists, Taber said. Like Rowell, he's heard the charge that he is "cheating," but he rejects the contention that the hybrids are luring people away from bikes.

"The Optibike isn't replacing a bicycle. It's replacing a car," he said.

Carol Silldorff, executive director of Bike Maryland (formerly One Less Car), said her group doesn't buy into the negative stereotype,

"Bike Maryland thinks they're a great idea for people who might want to go a bit faster or have an extra hilly ride," she said. "It can still be a lot of exercise."

But Silldorff has resisted the temptation to try out the technology. "I'm worried that if I try one I won't stick with this old woman-powered one I'm used to."

While the Optibike provides a high-end ride, its riders are no less vulnerable to traffic than low-tech bicyclists.

Rowell takes all the precautions recommended for bicyclists — helmet, fluorescent sign on the rear, powerful front and back lights — but he still knows there's an element of risk.

"You have to be on your game when you're out there. I'm two feet away from dying," he said. "I'm a Christian and pray for my safety every ride."

Electric bike riders are also subject to the same unpredictable misfortune that any bicyclist faces. The first day Rowell had an appointment to meet with a reporter, he showed up an hour late in one of the family cars.

His Optibike ran over a nail, and he had to ask his wife to pick him up.