The new dedicated bike lane on L Street NW in the District is almost open for business, meanwhile causing confusion and consternation. (Matt McClain/For The Washington Post)

Some see it as the tyranny of the two-wheelers, an encroachment that will make city traffic more miserable than ever. For others it is salvation from the risk of becoming a hood ornament.

It depends on where you sit: in a bucket seat or on a bicycle seat.

The latest in that 21st-century urban addition — the dedicated bike lane — is almost open for business on L Street NW in the District. Even before the final signs, markings and white bollards were in place — and days before the official ribbon-cutting — the new lane was causing confusion and consternation.

The lane, which will provide a vital link to a growing network, is wider than most bike lanes, encouraging cars to drive down it and delivery trucks to squeeze in beside the curb. It takes the entire left lane between New Hampshire Avenue and 12th Street, a stretch where every block has one or more underground parking garages that require cars to cross the bike lane.

This week, cars were pulling into the lane to make left turns, and cars pulling out of garages were rolling down them, too. A Heineken beer truck sneaked in to unload at a bar near 18th Street, and other delivery vans made use of it too.

Sharing the bike lane on L Street

Not to worry, said John Lisle, spokesman for the District Department of Transportation. Additional bike symbols on the pavement, signs going up this week and white bollards placed in the middle of the lane will help cyclists and drivers to go where they belong.

That’s the whole point of dedicated bike lanes.

The only tricky part on L Street, where all traffic is one-way in an eastbound direction, comes when cars want to turn left. They will cross over the bike lane at a designated place about 100 yards from the corner and drive between the bike lane and the curb until they reach the corner. Their path may be blocked by cyclists who plan to turn left too, but cyclists who are going straight will stay to the driver’s right in the bike lane.

“It’s going to take a period of adjustment, just like the 15th Street [bike] lane did,” Lisle said.

The District plans to have up to 80 miles of bike lanes when the system is complete, perhaps cementing its recent designation as one of the most bike-friendly cities in the country.

The notion of a bikes-only lane on city streets was the natural outgrowth of two things. One was a big jump in the number of people riding their bikes in urban settings, where a generation or two ago the only people on bikes were children and those who couldn’t afford a car, the bus or the subway. The other was a steady increase in urban traffic congestion.

Drivers and cyclists coexist in harmony most of the time, but when they collide what would have been a minor fender-bender between a couple of cars often yields a serious injury when a cyclist meets an SUV, even at slow speed.

Cyclists can confound and infuriate drivers when they don’t obey required traffic rules or practice common-sense safety.

Keeping the two apart where possible seemed a desirable goal. Cycling advocates say that while drivers may get squeezed, creating a dedicated bike lane encourages more people to ride — and that may mean fewer cars on the road.

New York Mayor Michael Bloomberg has championed the bike lanes, adding 250 miles of them despite protests from cabbies and U.S. Sen. Charles Schumer, who reportedly was unhappy when a bike lane appeared across the street from his home in Brooklyn.

When Gabe Klein, the District’s former transportation chief, took charge of Chicago’s Department of Transportation, he continued what he first launched in Washington. The Windy City has plans for 100 miles of bike lanes.

All of this energy for bike lanes in the U.S. is chuckled at by Europeans, who have been using bike lanes for decades. They say they’re more apt to take note when a street lacks a bike lane than when it has one.

Some cities have a long-standing tradition. In Copenhagen, 37 percent of commuters get to work or school on bikes during all but the most bitter weeks of winter. In Sweden, 17 percent of people say bikes are their primary way of getting about. Towns in the Netherlands reportedly are thinking about building heated bike lanes that would melt ice and snow so that cyclists could pedal through the winter.

Cycling in the Washington region has gotten a double boost in the last couple of years with the arrival of Capital Bikeshare, which provides almost 1,700 bikes on a per-ride basis to 18,000 annual members and more than 200,000 less regular riders, and expansion of the bike lane system.

The new L Street lane is an eastbound-only bike lane. One block to the north, a westbound lane is to be created on M Street next year. The two lanes will provide the crosstown links to several north-south routes.

“They’re pretty efficient,” said Gary Jocher, who may benefit from the new and planned additions more than any other single rider. He is the bicycle delivery man for Domino’s Pizza on L Street.

He said he first found the new L Street lane confusing, but “once they color it in, it will make a difference.”

The lane is marked with emerald green paint and set off from the adjacent traffic lane by short white bollard posts. The L Street lane intersects with the 15th Street bike lane, which is a major north-south bike artery.

Lisle said new parking for delivery trucks has been provided on L Street or adjoining streets so that businesses don’t suffer. And he said the new bike lane’s width — almost 12 feet — was twice as big as some other lanes for a reason.

“There are going to be so many cyclists in the city that we wanted to give them room so they could pass the slowpokes,” he said.

In the District, cyclists have the same rights as the drivers of motor vehicles and the same obligation to obey traffic laws, such as stopping at stop signs and stop lights. Drivers are required to maintain a three-foot distance from cyclists.

In the downtown area, cyclists are not allowed to ride on the sidewalk.

Bruce Majors, who this week lost a bid to unseat D.C. Del. Eleanor Holmes Norton (D) from her seat in the U.S. House, pedaled down the new bike lane Thursday on his way to the Grooming Lounge at 1745 L St.

“Hunting for a parking space makes me crazy,” he said, explaining why he chose to cycle on a chilly, windy afternoon. “It’s hard if you have a lot of stops to make.”

The bike lane was “a little bit confusing until they put the lines down,” he said, adding that when there’s no one on the sidewalk he sometimes rides there to escape “noisy and aggressive drivers.”

“I’d rather startle someone than be dead,” Majors said.