What's a turn signal?
Chapter 90: Section 14B. Uniform stopping and turning signals on ways.
Section 14B. Every person operating a motor vehicle, before stopping said vehicle or making any turning movement which would affect the operation of any other vehicle, shall give a plainly visible signal by activating the brake lights or directional lights or signal as provided on said vehicle; and in the event electrical or mechanical signals are not operating or not provided on the vehicle, a plainly visible signal by means of the hand and arm shall be made. Hand and arm signals shall be made as follows:-
1. An intention to turn to the left shall be indicated by hand and arm extended horizontally.
2. An intention to turn to the right shall be indicated by hand and arm extended upward.
3. An intention to stop or decrease speed shall be indicated by hand and arm extended downward.
Whoever violates any provision of this section shall be punished by a fine of not less than twenty-five dollars for each offense.