So much for the slow rollout.

Cops have been furiously writing tickets since the city speed limit was dropped from 30 mph to 25 mph last year — with summonses skyrocketing by more than 40 percent in the first three months, according to NYPD data obtained by The Post.

On Nov. 6, a day before the policy was put into place, Mayor Bill de Blasio promised to go easy on early enforcement of his speed law to let drivers get used to the new limits.

But rather than mercy, drivers felt the heat as speeding summonses increased by nearly 8,700 between November and January — from 20,486 to 29,179 — over the same period a year earlier.

In November alone, summonses doubled to 13,606 compared to the 6,600 handed out during the same month in 2013, according to the stats.

The number of speeding summonses was already on the rise in 2014 before the city lowered the limit following other Vision Zero initiatives and increased enforcement.

But after the speed limit for most city streets was reduced by 5 mph in early November, the increase was steeper, the stats show.

Speeding-ticket fines vary depending on how much over the limit a driver is going.

Sam Levy, vice president of Sinai Ambulette in Queens, said his fleet of 160 ambulettes has been racking up thousands of dollars in tickets ever since the new speed limit went into effect — even though they barely crack the 30-mph mark.

“It’s been a dramatic increase since the speed limit dropped,” he said at the DMV’s Traffic Violations Bureau center in Jamaica, Queens. “It used to be five tickets was a big week. Now it’s about 20 tickets a week. I’m paying roughly $2,000 a week for these slow speeding tickets.”

Levy, 32, said he recently showed up to the Rockaway Boulevard facility carrying a pile of tickets going back weeks in the hopes of having the hefty fines reduced, but found no sympathy.

“I came here to explain that it’s ruining my business, and they said, ‘Pay,’” according to Levy, who called the mayor’s promise to ease into enforcement a lie.

“[The rollout] was very fast. I noticed an immediate increase in tickets,” he said. “I have to explain to all the customers that we cannot do as many runs per day and we have to travel much slower now. I’m losing customers!”

De Blasio said in November that the new limit was not meant to blindside drivers.

“It will be phased in,” de Blasio said the day before the law went into effect. “We will be doing a lot of public education over the coming months. We’ll be doing a lot of warnings — obviously, enforcement over time.”

Officials also said at the time that cops could use discretion and focus on drivers traveling significantly over the limit.