CBS New York reports the grass-roots effort is aimed at slowing down traffic and reducing pedestrian tragedies. The group behind the campaign said ten communities in four boroughs put up over 100 signs over the weekend.
"Twenty (mph) is ideal for saving lives. If you're hit by a car going 30-mph you have a 50 percent chance of dying. If you're hit by a car going 20-mph you have a 95 percent chance of surviving," anti-speeding campaigner Keegan Stephan said.
He said citizens decided they couldn't wait for the city to act.
"We mapped out where communities had applied for Slow Zones and were rejected or were still waiting for groundbreaking on their projects," Stephan told the station.
The Department of Transportation told CBS New York it is committed to making the streets safer, wih a statement that said: "DOT is committed to installing additional slow zones and working...to lower New York City's speed limit and make our streets safer for everyone using them."
As a rule the city takes down unauthorized signs.The NYPD did not immediately respond to inquiries by CBS New York about the legality of the self-made speed limit signs.