The District has already established a foundation for bicycles to be a major mode of transportation expected to absorb new commuters.

Experts agree that the District's bike share program is a national model, and although the city may still have a long way to go before it reaches its 25 percent target for the share of commutes made by bike on foot, D.C. is already ahead of many American cities. Data from 2011 show a higher percentage of residents commuted by bike in the District than in Chicago, New York or Austin, Texas.

As the District continues to grow by about 1,100 residents a month, the city hopes bike travel can absorb some of that added congestion.

"Having these choices means we're going to be a city that continues to grow without being utterly paralyzed," said Harriet Tregoning, director of the D.C. Office of Planning.

Jeff Miller, head of the Alliance for Biking & Walking, said creating a more complete system of protected bike lanes -- which separates bicyclists from drivers using curbs or other objects more substantial than white paint on pavement -- is a necessary next step.

Recently, a vehicle lane on 15th Street was converted into a protected bike lane, and on L Street, a lane used for traffic during rush hour and parking during off-hours was converted into a protected bike lane. A new protected bike lane on M Street is in the works.

The mayor's Sustainable DC Plan proposes that the city double the number of bike lanes, growing them from 56 miles to 100 miles.

"If we can get more people on bikes, it's going to free up and make the street system better for people who drive," said Martha Roskowski, director of the bike advocacy group Green Lane Project.

- Eric P. Newcomer