Okla. Stat. tit. 47, § 47-11-606: Method of giving hand-and-arm signals

All signals herein required given by hand and arm shall be given

from the left side of the vehicle in the following manner and such

signals shall indicate as follows:

1. Left turn. Hand and arm extended horizontally;

2. Right turn. Hand and arm extended upward. A person

operating a bicycle may extend his or her right hand and arm

horizontally to his or her right; and

3. Stop or decrease speed. Hand and arm extended downward. A

person operating a bicycle may extend his or her right hand and arm

downward to his or her right side.