Whenever traffic at an intersection is regulated by the type of signal commonly known as a stop and go signal, the following colors shall indicate the following commands:
Red requires that traffic faced by this color shall stop and remain standing.
Green requires that traffic faced by this color shall move and continue to move, except when stopped for the purpose of avoiding an accident or when stopped at the command of a policeman.
Amber or yellow indicates preparation for a change in the direction of traffic movement.
When a red lens is illuminated by rapid intermittent flashes, drivers of vehicles shall stop before entering the intersection.
When a yellow lens is illuminated with rapid intermittent flashes, drivers of vehicles may proceed into the intersection only with extra caution.