§ 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.