WNYC has done a true public service and determined the approximate locations of many of the city’s controversial speed cameras. The cameras issue tickets to drivers going more than 10 MPH over the speed limit. In 2014, they generated a revenue of over $23 million in fines.

About half of the city’s 51 secret cameras, which are by-law required to be within a quarter-mile of a school, are mounted on NYPD vehicles. But the rest of them are posted at busy intersections or spots where vehicles are known to speed. Using ticketing data, WNYC mapped the locations that have “ticketed consistently as recently as January.” You can see them in the map below. The “inactive” site denotes either a mobile camera or a fixed-location camera that is no longer in operation.

If you’re driving in the city, here are the places to be the most careful:

The city is collecting a lot of ticket revenue. The most prolific camera was on the Shore Parkway in Coney Island, right off the Belt Parkway. It issued more than $2.75 million in tickets last year — 55,000 of them, at $50 a pop. That’s 100 times the tickets officers in that area’s 60th precinct wrote by hand.

The three top-ticketing cameras were all just off major roadways: the Long Island Expressway, the Belt Parkway and the Staten Island Expressway. All were in places where pedestrians don’t cross, because there’s nothing to cross to. The roads have fences on one side, blocking off the highways.

The cameras ticket almost three times as many drivers than officers do. However, they are also making crossings safer:

If the goal is getting people to slow down, the cameras seem to be working. According to WNYC’s analysis, the number of speeding tickets issued by each camera fell steadily over time.

Crashes dropped, too. In areas where we located installed cameras, there were 13 percent fewer collisions from September through December last year, compared to the same period in 2013.

Thanks to this map, however, you might be able to save $50 and still help keep the city safe.

(Photo: ‘Nino” Eugene La Pia)