§ 12-28. Hand and mechanical signals.

(a)

No person shall stop or suddenly decrease the speed of or 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 and then only after the giving of an appropriate signal in the manner provided herein.

(b)

An operator or driver when stopping, or when checking the speed of his vehicle, if the movement of other vehicles may reasonably be affected by such checking of speed, shall extend his arm at an angle below horizontal so that the same may be seen in the rear of his vehicle.

(c)

An operator or driver intending to turn his vehicle to the right shall extend his arm at an angle above horizontal so that the same may be seen in front of and in the rear of his vehicle, and shall slow down and approach the intersecting highway as near as practicable to the right side of the highway along which he is proceeding before turning.

(d)

An operator or driver intending to turn his vehicle to the left shall extend his arm in a horizontal position so that the same may be seen in the rear of his vehicle, and shall slow down and approach the intersecting highway so that the left side of his vehicle shall be as near as practicable to the center line of the highway along which he is proceeding before turning.

(e)

The signals herein required shall be given either by means of the hand and arm or by a signal light or signal device in good mechanical condition of a type approved by the state highway patrol; however, when a vehicle is so constructed or loaded that a hand-and-arm signal would not be visible both to the front and rear of such vehicle then such signals shall be given by such light or device. A vehicle shall be considered as so constructed or loaded that a hand-and-arm signal would not be visible both to the front and rear when the distance from the center of the top of the steering post to the left outside limit of the body, cab or load exceeds 24 inches, or when the distance from the center of the top of the steering post to the rear limit of the body or load thereon exceeds 14 feet, which limit of 14 feet shall apply to single vehicles or combinations of vehicles. The provisions of this subsection shall not apply to any trailer which does not interfere with a clear view of the hand signals of the operator or of the signaling device upon the vehicle pulling said trailer; provided further that the provisions of this section as far as mechanical devices on vehicles so constructed that a hand-and-arm signal would not be visible both to the front and rear of such vehicle as above provided shall only be applicable to new vehicles registered within the state after the first day of January, 1954.

State law reference

For similar provisions, see RSMo 304.019.