A. The signals herein required shall be given either by means of the hand and arm outside the left side of the vehicle, or by a signal lamp or signal device which will convey an intelligible warning to other traffic approaching from the front or rear; but 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 must be given by such lamp or device.
B. Hand and arm signals shall indicate as follows:
1. Left turn: Hand and arm extended horizontally;
2. Right turn: Hand and arm extended upward;
3. Stop or decrease speed: Hand and arm extended downward;
4. Reentering moving traffic lane from parked position: Hand and arm extended horizontally;
5. Changing lanes: Same as subsections B1 and B2 of this section, depending on direction of change.
C. The opening of a door of a vehicle shall not constitute a signal as required by this title. (Prior code title 46, art. 11 § 199)