The controversial car ban on a one-mile stretch of Manhattan’s 14th Street went into effect Thursday — proving to be a real pain in the gas for motorists.

The change along the typically busy crosstown route between Third and Ninth avenues prohibits car drivers from the stretch between 6 a.m. and 10 p.m., forcing them to veer off into side streets in an effort to give city buses a clear path.

“I’m angry,” said William Mabry, 63, owner of a plumbing company, as he tried to make his way to First Avenue and East 64th Street from Brooklyn. “Now, I have to make a detour … I’m late now.”

An Uber driver who was called to a home on 14th Street was forced to pick the passenger up around the corner.

“My client is upset,” the cabbie said. “I’m not the angry one, but someone is angry with me.”

Another motorist whose son goes to school just blocks away from 14th Street said he had trouble getting his child there.

“I have been circling around,” said the motorist, who would only identify himself as Willie. “It doesn’t make me feel comfortable. I might have to drop him off and let him walk.”

Bus drivers, however, raved that the change was working out great for them.

“I like this,” said a driver of an M14A bus. “I move [the bus] faster because I don’t have to deal with the heavy traffic that I’m used to seeing.”

Commuters were also happy.

“It took 20 minutes,” said a woman who got on a bus at Avenue D and East 10th Street and got off at Seventh Avenue. “Normally it would take more than a half-hour.”

The strip of 14th Street will remain limited to buses, large trucks and vehicles making local deliveries or pickups and drop-offs from 6 a.m. to 10 p.m. daily for 18 months.

Under the rules, any other drivers who use the strip are required to take the next available right turn or be slapped with violations and fines, thanks to automated bus lane enforcement cameras. Left turns from 14th Street are also prohibited.

The city, however, says those fines won’t be issued until Dec. 2, following a 60-day warning period.

Still, on Thursday some cars ignored the ban along the strip where NYPD traffic agents were deployed.

“Most of them do turn, but some slipped by,” one traffic agent said. “What are you going to do? I can’t stop them.”

The launch of the car ban was delayed more than three months due to a lawsuit brought by a local block association concerned about gridlock on side streets.

Residents remained skeptical Thursday.

“It’s going to push all the traffic onto 15th Street and 13th Street and it’s tough enough there trying to find parking,” said one neighbor, who only identified himself as Jeff. “I’m not happy … I don’t think it was a good idea, but we will see.”