The District is building a bike lane on L Street Northwest that will eliminate 150 parking spaces and require a whole new set of rules for both motorists and cyclists.
The new lane, which the District Department of Transportation started installing late Monday, will be on the left side of the one-way street and will require motorists turning left to yield to bicycles.
The new configuration, a first for D.C., will create "mixing zones" at intersections that cars and bikes will have to navigate.
The bike lanes between those zones will be separated from traffic by white posts and will be painted green near intersections to make it easier for motorists to remember to check for cyclists, officials said.
Special boxes will also be painted on the roadway near crosswalks for cyclists wishing to turn right. Those cyclists would use the boxes to get to the right side of the road while traffic is stopped at a red light.
"This whole area is going to have to take a lot of communication -- manners, even," DDOT planner Jim Sebastian said Tuesday.
City officials said they're expanding bike lanes in hopes of reducing congestion. District officials aim to have 5 miles of bike lanes by the end of the year, including the lane on L Street.
The District is one of six U.S. cities getting technical and public-relations support from the Green Lane Project, a nonprofit funded by bike manufacturers that helps cities expand cycling lanes.
The organization flew District transportation officials to the Netherlands and New York to study how bike lanes there worked.
"Cities like Washington, D.C., are leading the way in figuring this out," said Green Lane Project Director Martha Roskowski.
Roskowski said the lanes help uneasy bike riders feel safe.
"The No. 1 reason people don't ride bikes is safety. They feel scared. They are worried they're going to get hit by a car," she said.
DDOT is also designing a bike lane for M Street NW, which officials plan to install next year. The M Street lane will also be using "mixing zones," officials said.