WASHINGTON – Safety devices meant to put an end to illegal U-turns on Pennsylvania Avenue have frustrated some of the very people they’re meant to protect.

The devices, called “zebras” are raised black and white bumps that run along a one block stretch of the Pennsylvania Avenue bike lanes. But many bike advocates are upset with the installation.

Ryan Sigworth, a D.C. resident, urban planner and blogger, says the zebras were improperly installed.

“The manufacturing recommendations on the separation is 8.2 feet,” but, Sigworth continues, “they’re actually spaced on 15-foot separations.”

Sigworth says this is a problem because cars can easily slip between the zebras and continue to make those illegal U-turns. In a photo that accompanies Sigworth’s post on the Greater Greater Washington website, there’s a photo showing an SUV crossing the bike lanes on the very block — between 12th and 13th streets — where the Zebras were installed.

Erik Kugler, one of the owners of Bicycle Space, a D.C. bike shop, is equally frustrated.

“It’s a half-hearted measure at best,” Kugler says. He doesn’t understand why the zebras were spaced so far apart.

Jim Sebastian, the bicycle program coordinator at the D.C. Department of Transportation confirms that the spacing does not conform to the manufacturer’s recommendations, but says there’s a reason for that.

“We spaced them the way we did to match up with the striping” of the bike lanes says Sebastian.

“We’re trying to meet some aesthetics as well.”

Indeed, one of the factors that led to the choice of the zebras is their low profile. They don’t interfere with the street view to the U.S. Capitol.

Sebastian says the installation is being tested. Traffic counts were done before the installation and will be done during the testing period.

“They’re centered on these spaces between the lines. If it does prevent U-turns, then why would we decrease the spacing? We’ll see if they go down and we’ll add more if we need to.”

D.C. resident Cathy Mims says she’s aware that cyclists have been hit by cars making illegal U-turns right through the cycle track.

“Even though they put up No U-Turn signs, people still make U-turns, so now they can’t. So I think it’s a good thing.”

But another D.C. resident who didn’t give her name, complained about road conditions in general.

Referring to the Zebras, she said, “they don’t need anymore bumps in the street.”

Instead she said road crews need to put their attention elsewhere.

“They need to work on these craters and potholes” that dot the city’s streets said the resident.

A pedicab operator who identified himself as Alex said of the zebras, “they’re probably going to help, but I’d hate to see a cyclist who’s not aware of them come flying through here really fast and wipe out on one of them.”

Several cyclists didn’t notice the black and white safety devices. Harry, a cyclist from Fort Belvoir, who declined to give his full name, said even without the zebras, safety on the Pennsylvania Avenue cycle track has actually improved.

“It used to be you were taking your life in your hands on Pennsylvania Avenue, but the word’s gotten out: more people are comfortable with bikers,” said Harry, who added that it makes cyclists use the road better too.

” I see more bikers obeying the stop signs, stopping for the lights.”

Adam Bridge noticed the zebras and thinks they’re pretty nice.

But, he explained, “I don’t feel unsafe riding here. I think the bike track down Pennsylvania [Avenue] is a great idea.”

Bob McKeon, Deputy Chief Counsel at the D.C. Office of Tax and Revenue, echoes Bridge’s sentiment: He doesn’t feel unsafe using the lanes without the Zebras, but says they may be a good addition.

Of the bike lanes McKeon says, “It’s the best ride in town. I don’t think you get more of a picturesque ride than going down Pennsylvania Avenue in the middle of the road.”

WTOP’s Kate Ryan contributed to this report.