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:
Whoever violates any provision of this section shall be punished by a fine of not less than twenty-five dollars for each offense.
Mass. Gen. Laws ch. 90, § 14B