A cyclist was hit by a taxicab making a U-turn on Pennsylvania Avenue NW in of the Wilson Building last November.

Officials from three D.C. government agencies took to a very visible stretch of Pennsylvania Avenue NW today to warn motorists—especially cab drivers—that not only is it not cool to make a U-turn through the cycle track in the middle of the roadway, doing so will now come with a fine.

After complaints and demonstrations from the city’s biking population late last year, Mayor Vince Gray signed emergency legislation that makes pulling a U-turn through the bike lanes punishable by a $100 fine. The action today taken by the Metropolitan Police Department, District Department of Transportation, and D.C. Taxicab Commission wasn’t a punitive measure, but was meant to be a strong show of force that cutting across bike lanes and potentially imperiling oncoming cyclists is now illegal at all times.

On the block of Pennsylvania Avenue outside the John A. Wilson Building, police officers, traffic control officers, and taxicab inspectors passed out fliers to passing drivers, letting them know that their days of swooping through the clearly marked cycle tracks are over, or, at least, should be over. Of the 14 bike crashes on Pennsylvania Avenue NW in 2010 and 2011, 11 involved cars making U-turns, according to a DDOT statement.

“A one-day event to educate folks is a good first step,” Shane Farthing, the executive director of the Washington Area Bicyclist Association, said. “How is this going to become a long-term priority?”

At midday, the thoroughfare was sparsely filled, and the skeleton of the D.C. government’s inaugural parade reviewing stand still jutting out into the right-most lane made 180-degree turns seem implausible. But officials passed out the fliers to whoever was rolling by, whether on four wheels or two.

“The next step is to let people know the law has changed,” Farthing said. “As long as it has a deterrent effect we want to see it broadly enforced.”