Mayor Bloomberg joined Transportation Commissioner Janette Sadik-Khan and NYPD Chief of Transportation James Tuller outside a Crown Heights high school this morning to announce the impending launch of the city’s first automated speed enforcement program. Cameras issuing fines for drivers who exceed the speed limit by 10 mph or more will begin operating on September 9, when students head back to school, though for the first few weeks the program will only send violators warnings.

Speeding was the leading cause of traffic deaths in NYC last year, contributing to 81 fatal crashes. Still, the state law enabling automated enforcement of the speed limit — which passed after several previous attempts had died in Albany — includes several restrictions. The city has just 20 cameras to work with, and they can only be placed within a quarter-mile of schools. They can’t be operated at times when classes or after-school activities are not in session. On the plus side, the city will be able to move the cameras to different locations, providing some flexibility that should help reduce egregious speeding on a greater share of NYC’s 6,000-mile street network.

To prevent motorists from selectively slowing down near known camera locations, the city is not disclosing the locations of these enforcement cameras. However, the site of today’s press event — W.E.B. DuBois High School on Eastern Parkway and Bedford Avenue — is “a candidate to receive speed camera technology nearby due to a high crash rate in its vicinity,” according to a press release from the mayor’s office.

“Keeping streets safe for motorists, cyclists, and pedestrians is one of the most important public safety challenges any government faces,” Bloomberg said in the announcement. “Our streets are the safest they have ever been, due in large part to our enforcement efforts and innovative traffic engineering that have brought traffic fatalities to record lows. Curbing speeding around schools will help us continue to make our City’s streets safer for everyone.”

The cameras will start monitoring speeds on the first day of the school year, September 9, but the mayor’s office says the $50 fines for violators won’t start until a few weeks later:

DOT will begin the five-year program with a combination of fixed and mobile cameras at unspecified locations, which will be determined based upon factors such as crash and injury data, rates of speed and road geometry. During the initial weeks of the program and in order to send a message to speeders, DOT will only issue warning notices to motorists found on camera to be speeding in excess of 10 or more miles above the posted speed limit before eventually issuing $50 fines for the offense. Violations would be issued to the vehicle owner and will be adjudicated by the New York Parking Violations Bureau.