RSA 265:45 Turning Movements and Required Signals.

I. No person shall turn a vehicle at an intersection unless the vehicle is in proper position upon the roadway as required in RSA 265:42, 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.
II. A signal of intention to turn right or left when required shall be given continuously during not less than the last 100 feet traveled by the vehicle before turning.
III. 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