As a queue of cars waits to exit the National Institutes of Health onto Rockville Pike at rush hour, Diane Bolton breezes by on her bicycle.

“I would pay for this commute,” said Bolton, 34, of the District, who is one of about 600 NIH employees, the campus’s bike club estimates, who bike to work at least once a week.

Federal agencies now offer a $20 monthly subsidy to employees who bike to work to encourage commuters to use other forms of transportation.

NIH officials also want employees to cycle to work or participate in other commuting programs aimed at reducing the number of cars coming to campus in anticipation of the merger of the nearby National Naval Medical Center with Walter Reed Army Medical Center in September. The move is expected to bring up to 2,500 new employees to the Bethesda military campus and nearly double annual visits, from 600,000 to 1 million.  

Although Congress approved the subsidy for all federal agencies last year, the program has been slow to start at NIH; the agency began to offer the benefit June 1.

Conditions that the Internal Revenue Service has imposed on those who accept the subsidy has some bikers, including Bolton, passing: To get the $20 each month, employees must give up other federal transportations benefits, such as a parking space or up to $230 a month to pay for public transit fares.

“That parking space is too valuable to be sacrificing,” said Bolton, who has not taken the subsidy. She estimates that she makes the 10-mile ride to work all but four days a month — but on those four days when weather is poor, or she is physically unable to ride, her $80 Metro allowance is invaluable, she said.

Rep. Earl Blumenauer (D-Ore.), who sponsored the legislation, has introduced to Congress a bill that would allow commuters to combine the biking subsidy with other transit benefits.

Thirty-eight NIH employees have signed up for the subsidy — 29 from the agency’s Bethesda headquarters and other locally leased buildings, and nine from out-of-state NIH facilities, said Tom Hayden, NIH’s director for the division of amenities and transportation services. About 18,000 people work at NIH’s Bethesda campus, he said.

“This is going to be part of the solution in how we get folks to the campus,” said Hayden, who added that he hopes to increase program participation by at least 15 percent within the next year.

Getting employees to the campus has become a pressing issue as officials brace for the opening of the Walter Reed National Military Medical Center and construction projects planned for the area begin.

About $165 million in construction projects is planned for the sidewalks, road intersections and Metro access near the Navy Med campus. The earliest of the intersection work is not expected to be complete until 2012.

Local, state and federal officials have warned that construction for these projects will exacerbate the area’s traffic problems. Officials are encouraging people who work in the area or who commute to work via Rockville Pike to seek alternate transportation options.

Spencer Iscove, 54, of Rockville, is among NIH’s bike commuters who plan to sign up for the subsidy. Iscove bikes from his home in Rockville to NIH’s Rockledge Drive building, just south of Interstate 495, he said. The subsidy may not be much, but Iscove said he is certain he can put the money to good use.

“Twenty dollars would definitely pay for illuminating me on the roadways during the year,” he said. “It’s not a lot of money, but it can be used appropriately.”

Iscove is among the bikers who believe that requiring employees to give up their other benefits would deter them from biking.

“They’re going to say, ‘Why bother? I’ll keep driving,’ ” he said.

Perry Skeath also bikes to work almost every day. But the 58-year-old Silver Spring resident has no plans to sign up for the subsidy.

“It’s sort of an all-or-nothing deal,” he said. “A lot of people’s lives, including mine, are not all-or-nothing.”

Despite how much he enjoys his morning ride, Skeath is not interested in risking his safety by biking on ice in the winter, so giving up other transportation options does not make sense, he said.

Although the bike subsidy may not push people to give up their cars, a bike club on campus has converted its fair share of commuters.

The NIH Bicycle Commuter Club, established in 1980, maintains an Internet mailing list and a Web site that helps cyclists sign up for benefits such as Bike Bucks — log 100 miles and get five Bike Bucks, which can be redeemed at select bicycle shops in the Bethesda area and put toward NIH bicycle club jerseys or NIH fitness center membership.

The public forum on the club’s Web site, through which bikers swap route ideas, helped Skeath determine the best way for him to get from his home in Silver Spring to his office. He said he does not consider himself a club member but added that the club’s resources are important to the biking community.

“[The route] makes a huge difference of whether it’s a pleasant ride or a stressful ride,” he said.

The club does not have an official membership. Jenny Haliski, a spokeswoman for the group, said the group considers about 600 people who participate in the e-mail list and bike regularly to work as part of the club.

The group qualifies for funding from the Department of Recreation and Welfare, which oversees campus clubs at NIH, but the club has not applied for or received funding in the past few years because the money cannot be used for consumable items, such as the air pumps the club would like to station around campus, said Bolton, who serves as an officer for the group. In the past, the club has used Recreation and Welfare Department money to purchase signs for events, such as the annual Bike to Work Day, she said.

Club members agreed that the number of people who bike to the Bethesda campus has increased over the years, and that amenities such as locker rooms and bike racks have been improved. As for whether the new subsidy will contribute to that trend, they are less certain.

“It’s a nice gesture,” Bolton said.