Mayor Lori Lightfoot wasn’t kidding when she talked about “pushing, pushing, pushing” Police Superintendent Eddie Johnson to make “tough decisions” that he has “not been called upon to do before.”

On Friday, the mayor did it for the superintendent she inherited.

Lightfoot announced plans to re-open two detective areas shuttered by former Mayor Rahm Emanuel and merge the administrative functions of the Chicago Police Department, the Chicago Fire Department, and the Office of Emergency Management and Communications into a new Office of Public Safety Administration at police headquarters in Bronzeville.

The immediate impact will be to “re-direct 151 sworn officers and 11 uniformed fire personnel from headquarters” to Chicago neighborhoods, officials said.

Emanuel balanced his first budget by eliminating more than 1,400 police vacancies, reducing police and detective areas from five to three, and closing three district police stations: Wood, Belmont and Prairie.

When homicides and other violent crime spiked, Emanuel was forced to rely on runaway overtime before reversing field and embarking on a two-year plan to hire more than 1,000 additional officers.

Lightfoot now plans to re-open two detective areas: the Harrison Area on the West Side and the Grand Central Area on the Near Northwest Side.

The goal is to boost Chicago’s dismal but improving homicide clearance rate by increasing “collaboration” between detectives and patrol officers, decreasing travel times to let detectives spend more time “in the field” and reducing skyrocketing overtime.

“It was a failed experiment ... Three areas was just too much geography to cover — both for patrol and for detectives,” Lightfoot’s chief of staff Maurice Classen, the police department’s former director of strategy, said of Emanuel’s decision to close the two detective areas.

“We need to put more detectives out in the areas, in the districts so they can have more connection with front line officers, more connection with cases. That also decreases the amount of travel that it takes to get to [crime] scenes. Not only will it lead to ... less exhaustion. It’ll decrease overtime.”

Former Mayor Jane Byrne once created an Office of Public Safety to move one police superintendent out of the way to make way for another she preferred.

Lightfoot’s new Office of Public Safety Administration is not about politics. It’s about efficiency, cost-cutting and putting more officers on the street.

Roughly 280 civilian employees in the finance, human resources, information technology and logistics divisions will come together at the new office at 35th and Michigan.

No civilian personnel will lose their jobs. But the consolidation is expected to generate “savings over time” by replacing sworn officers with civilians and by reducing overtime expected to top $200 million this year for the three departments.

Virtually every Chicago mayor talks about moving police officers from desk jobs to the street. None has managed to pull it off, acknowledged Budget Director Susie Park, CPD’s former deputy chief of finance and administration.

“What makes this different is that we are creating a separate agency for this to actually succeed ... That allows us to focus on hiring those civilians,” Park said.

“The last round we went through, we hired the people. We have officers back on the street. And then they make their way back in.”

The changes announced Friday are the “first down payment” toward “moving people back to the street,” Classen said. The next step is to eliminate some of the roughly 135 specialized units and move those officers back to the districts.

“We’re hoping to get another couple hundred [officers] from that,” he said.

Classen refused to identify specialized units on the chopping block, saying the mayor’s office is still “auditing where people are.”

But, he said, “There are places across the department that we’re gonna be looking at that we think can actually be moved back to the street. You’ll hear more about that in the coming weeks.”

Classen noted the New York Police Department created so many specialized units that Police Commissioner James O’Neill remembers there being “a homicide where only one car showed up” when he served as a precinct commander.

“There’s nothing wrong with having specialized units. [But] we don’t have enough people on the street,” Classen said.

The press release distributed by the mayor’s office quoted Johnson as saying he “welcomes” the change.

Classen underscored the point.

“The superintendent has always said that he’s a neighborhood police guy. He’s a community policing guy. He wants people back in the districts,” the chief of staff said.

“As we’ve gone through this staffing surge, his feeling has been, we’ve got more people in the department. But we’re not getting enough back to the districts. He’s in support of anything that gets people back to the districts.”