New York Laws
Article 28 - Turning and Starting and Signals on Stopping and Turning
1165 - Method of Giving Hand-and-Arm Signals.

ยง 1165. 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.

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