D.C.'s newest major bike lane on L Street NW is causing confusion for drivers and frustration for bikers, as truckers and commuters park in the lanes because they don't know they're not supposed to, or they don't care.

Parked trucks and cars frequently block the L street bike path, which was opened last fall and replaced 150 parking spaces on the north side of the street.

The parked vehicles force cyclists to move into speeding traffic and discourage riders from using the lane, said Shane Farthing, president of the Washington Area Bicyclist Association, who rode the lane Thursday night only to find two cars in the way.

"It's a common problem, and there are some enforcement problems and design issues," he said. "I think it's a big deal."

The problem is much worse in the L Street lane than it is on other bike lanes, Farthing said.

There's no official count on how many cars are breaking the rules by parking in the bike lane, but Jay Corbalis, who created the blog "Who's blocking the L Street bike lane today?" says readers send him two or three photos of parked cars in the lane every day, and that he sees four or five vehicles park there on the block near his workplace every day. Many of those are delivery trucks; some are police vehicles.

"I ride my bike to work each day and use the L Street bike lane and just noticed there were a lot of cars parked in there at times, and I just wanted a venue to chronicle that phenomenon," Corbalis said.

The D.C. Department of Transportation is planning to add more white posts along the lane once snow season is over to discourage cars from entering, said bike lanes coordinator Mike Goodno. The posts are 20 feet apart, creating plenty of room for cars to wedge between them.

"We have been sending our traffic control officers out there on occasion to do some enforcement. Unfortunately, it hasn't been as consistent as we would like since they have other duties," he said. "We continue to see the problem."

By early summer the District may add a curb to the bike lane, Goodno said. And a bike lane planned for M Street may also have a curb and will be narrower to keep cars out, he said.