Sec. 10. Signals by lights or semaphores.
Red indicates that traffic then moving shall stop and remain
stopped as long as the red signal is shown.
Green indicates that traffic shall then move in the direction of
the signal, and remain in motion as long as the green signal is
given.
Amber indicates that a change is about to be made in the directions
of the movement of traffic. When the amber signal is shown
traffic which has not already entered the intersection including the
crosswalks, shall stop, but, that which has entered the intersection
shall continue to move until the intersection has been entirely
cleared.
When semaphores are not in operation the use of an amber
light indicates need for caution. (Id.)
