State law says New York City can lower speeds on streets within a 1/4 mile of school. That's 55% of city's streets -- including 3/4 of those in Manhattan and more than 2/3 of those in Brooklyn and The Bronx.  WNYC/Transportation Nation mapped the streets near public schools, as momentum builds for a law to restrict driving speeds to 20 mph in parts of the city.

UPDATE: Since this article was published, WNYC has added private and parochial schools to the map, increasing the miles of streets calculated within 1/4 mile of a school. Read the updated story.

Just two weeks ago, the City Council heard emotional testimony from a Brooklyn family that lost their twelve-year old son, Sammy Cohen Eckstein, after being struck by a car on Prospect Park West.

Council members — some of them reeling from recent pedestrian fatalities in their districts — are considering legislation that would lower the speed limit in some residential neighborhoods to 20 miles per hour. One big stumbling block: such a move would require the approval of the state legislature. (New York's vehicle traffic law states that no city or town can establish a speed limit of less then 25 miles per hour.)

But there is a loophole.

Kate Slevin, an assistant commissioner with the New York City Department of Transportation, explained to the council that the city does have some autonomy. "We can do 15-24 miles per hour within a quarter mile of a school," she said, promising to get that data to the council.  The city DOT has yet to furnish such a map, so WNYC's data news team mapped those areas.

Here's the upshot: 55 percent of all New York City streets are within a quarter mile of a school. In Manhattan, that number climbs to 75 percent. Seventy-one percent of Brooklyn's streets are in a school zone. In the Bronx, it's 64 percent; in Queens, 48 percent; and in Staten Island, 28 percent of all streets are in a school zone.

Councilman Jimmy Vacca, who chairs the transportation committee, called that data "very significant" and said he'd push legislation in the council to limit speeds in those areas.

The idea is gaining acceptance — even from some people who normally bristle when it comes to regulation.

"I'm not concerned about that. I'm not concerned at all about that," said Michael Woloz of the Metropolitan Taxicab Board of Trade. He said the 5,200 medallion owners he speaks for are in favor of lowering the speed limit — because they don't think it will lead to a ticket blitz. "I have never heard of a taxi driver getting gratuitously ticketed for speeding on side streets."  

A spokesman for Mayor-elect Bill de Blasio says, in general, he supports lower speed limits. But the council isn't waiting. 

Vacca says he'd like to bring a bill to the full council for a vote even before the new mayor is sworn in.

Of course, enforcement counts. 

At the City Council hearing two weeks ago Gary Eckstein said even after the death of his 12-year-old son his wife can prove cars still speed down his Brooklyn street.

"Just yesterday morning," he said, "Amy used a borrowed radar gun to clock the speed of vehicles traveling in front of our home on Prospect Park West, where Sammy was killed...In the span of approximately 15 minutes, 25 vehicles — many of them large commercial vehicles — exceeded the 30 mile per hour limit." 

Mayor-Elect de Blasio has said he would be committed to stepping up enforcement.