2010 New York Code
VAT - Vehicle & Traffic
Title 7 - RULES OF THE ROAD
Article 28 - (1160 - 1166) TURNING AND STARTING AND SIGNALS ON STOPPING AND TURNING
1163 - Turning movements and required signals.

§ 1163. Turning  movements  and  required signals. (a) No person shall
  turn a vehicle at an  intersection  unless  the  vehicle  is  in  proper
  position  upon  the roadway as required in section eleven hundred sixty,
  or turn a vehicle to enter a private road or driveway, or otherwise turn
  a vehicle from a direct course or move right  or  left  upon  a  roadway
  unless  and  until  such movement can be made with reasonable safety. No
  person shall so turn any vehicle without giving an appropriate signal in
  the manner hereinafter provided.
    (b) A signal of intention to turn right or left when required shall be
  given continuously during not  less  than  the  last  one  hundred  feet
  traveled by the vehicle before turning.
    (c)  No  person shall stop or suddenly decrease the speed of a vehicle
  without first giving an appropriate signal in the manner provided herein
  to the driver of any vehicle immediately  to  the  rear  when  there  is
  opportunity to give such signal.
    (d)  The  signals  provided  for  in section eleven hundred sixty-four
  shall be used to indicate an intention to turn, change lanes,  or  start
  from  a  parked position and not be flashed on one side only on a parked
  or disabled vehicle, or flashed as a courtesy or  "do  pass"  signal  to
  operators of other vehicles approaching from the rear.
    (e)  The  driver  of  a  vehicle equipped with simultaneously flashing
  signals as provided for  in  subdivision  eighteen-a  of  section  three
  hundred  seventy-five shall use such signals when the vehicle is stopped
  or disabled on a public highway, except when such vehicle is stopped  in
  compliance  with  a  traffic-control  device or when legally parked. The
  driver of a vehicle so equipped may use such signals whenever  necessary
  to warn the operators of following vehicles of the presence of a traffic
  hazard ahead of the signaling vehicle, or to warn the operators of other
  vehicles  that  the  signaling  vehicle  may itself constitute a traffic
  hazard, taking into account traffic and highway  conditions.  No  person
  shall use such signals for any other purpose.