Capital Bikeshare has expanded from the original 114 stations six years ago to 426 this month. Membership in the past two years has grown from 24,000 to 31,600. This month the system reached nearly 15 million trips. (Sarah L. Voisin/The Washington Post)

When Allie Toomey grew weary of Metro’s chronic delays and service disruptions, she turned to the Capital Bikeshare station a block from her Pentagon City apartment. Now she commutes by bike.

“It is a lot less hassle,” said Toomey, 27, a social media manager at a nonprofit organization in Crystal City. “I am in control of my commute. There is no traffic and no major incidents. But you never know with Metro anymore.”

As Metro service has continued to decline in recent years, the region’s system of 3,700 bikes — and counting — has increasingly become a favorite commuting alternative. Making that possible is the widespread access to the distinctive red bicycles as new stations are added to neighborhoods within the District’s eight wards and areas as far away as Reston, Va., and Shady Grove, Md.

Ridership trends this year suggest growing use of the bike system around Metro’s SafeTrack zones. The massive, year-long maintenance program has meant partial shutdowns, continuous single-tracking and the accompanying delays and crowding. The program has provided bike enthusiasts with an opportunity to promote bike-sharing as an alternative.

[SafeTrack closures: These D.C. Metro lines and stations will be disrupted in the next year]

Transportation officials and biking advocates say SafeTrack also has validated Capital Bikeshare’s value to the region’s transit network.

“People are discovering these other modes besides Metrorail during SafeTrack, and [Capital] Bikeshare is one of them,” D.C. transportation planner Jim Sebastian said. “It has been a real success and a real asset for our transportation system overall. A lot of people have come to rely on it.”

The bike program is so integrated into the region’s transportation system, he said, that not only is it used to get to Metro, but it also has replaced some Metro trips.

Systemwide, the number of trips since the beginning of SafeTrack in June increased about 7 percent compared with June to November 2015 — from 1.7 million trips to more than 1.8 million.

In addition, Capital Bikeshare has sold 186,000 $2 single-fare trips, which were introduced when SafeTrack began. One-day and single-trip fares are also up about 58 percent compared to pre-SafeTrack numbers, Sebastian said. Bikeshare’s busiest week in its history was July 11-17, when 92,441 trips were taken, coinciding with a line segment shutdown between Reagan National Airport and Pentagon City stations, affecting the commutes of thousands of Blue and Yellow line riders in Northern Virginia.

Bike counts in Arlington and Alexandria were up during those early SafeTrack surges. But Bikeshare ridership has been steadily increasing with the system’s growth, too, which has expanded from the original 114 stations six years ago to 426 this month. Membership in the past two years has grown to 31,600 from 24,000. This month, the system reached nearly 15 million trips.

Fifty-eight stations have been added to the system this year, including 31 in the District, which has the largest concentration of bikes and members. And, before the year closes, officials say at least five more stations will debut.

The most significant addition to the system this year was in Fairfax, which joined the regional program with plans to open 15 stations in Reston and 14 in Tysons Corner.

Capital Bikeshare started in the District and Arlington in 2010 and has expanded to Alexandria and Montgomery and Fairfax counties.

[Capital Bikeshare arrives in Fairfax County]

In the District, where a push for more bike infrastructure in recent years has led to a biking renaissance, officials are responding by installing an additional 30 stations next year in neighborhoods across the city.

The District’s portion of the program costs about $7.5 million a year to operate, but the city recovers 80 to 90 percent of the costs through memberships and advertising, Sebastian said.

Other participating jurisdictions recover a smaller percentage of their costs. Still, their officials say they see a big payoff from the program.

“Certainly, Bikeshare is an integral part of the overall multimodal transportation system that ­Alexandria wants to offer to its residents,” said Carrie Sanders, the city’s deputy director for transportation and transit. “It often serves as an important connection between neighborhoods and the Metrorail stations.”

Alexandria installed 14 docking stations this year and will add two more before the end of the year. The city will end the year with twice the number of stations it had last year, and officials say there is money to add 10 stations a year for the next few years.

Montgomery, which joined the system in 2013, added its 58th docking station last week at Sligo Avenue and Carroll Lane in Silver Spring. It was the county’s seventh station to be added this year, and there are plans to add nearly 20 more over the next year, expanding the program’s reach to Wheaton, Shady Grove, White Flint and Twinbrook.

Capital Bikeshare provides a variety of membership options. An annual membership costs $85, but users can also buy a month-long membership for $28. If you’re looking for even less of a commitment, there’s a three-day membership for $17 — or you can pay $8 for a 24-hour pass.

Long-term members get their own key to unlock bikes from docking stations; short-term members get an access code. The first 30 minutes of riding are free; fees accrue until the bike is returned to another station. Throughout the day, Bikeshare employees collect bikes from popular locations, such as downtown, and shuttle them back to neighborhoods for reuse.

In some areas, including Toomey’s neighborhood in Arlington, Capital Bikeshare has become so popular that it’s getting increasingly difficult to find available bikes.

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On the first day of the current SafeTrack “surge” affecting the Red Line, some commuters reported having to visit multiple sites to find bikes or docking stations.

But biking has become the easiest and best commuting option for Toomey. She started to bike more regularly after Metro’s Silver Line opened two years ago and cut train frequency on her regular Blue Line route. Then came SafeTrack, bringing even more dysfunction to the system, she said. She decided to ditch Metro — even for nonwork trips.

“I can take the Metro, but the Bikeshare is so much faster and cheaper — a lot cheaper,” said Toomey, who saves a $2.15 one-way Metro fare with a 12-minute bike ride to work using her annual membership.

“You can just grab a bike and drop it off somewhere. I don’t have to worry about storing a bike or having a bike stolen,” she said. “You don’t have to wait on the Metro.”