Pennsylvania Laws on Traffic Control Signals

Traffic Lights

Constitutional Statue 3112 of Pennsylvania law describes the function of traffic signals and mandates the correct behavior for each type of signal. The general rule is that traffic signals may only use green, yellow, and red lights, except for special pedestrian signals that have a word legend, which are the "walk" and "don't walk" crossing lights.

Green Lights

Vehicles facing a green light may proceed through the intersection or make a left-turn unless prohibited by a sign. Vehicles making a turn must yield to other vehicles or pedestrians in the intersection or crosswalk.

Yellow Lights

Traffic facing a steady yellow light are warned that a red light is following. Pedestrians facing a yellow light are advised that there is not enough time to cross the intersection before a red light, and may not start to cross the road.

Red Lights

Traffic facing a steady red light must stop at the designated line. If there is none, than a vehicle must stop before the crosswalk. If a crosswalk isn't present, a vehicle must stop before entering the intersection. Until the light changes, traffic must remain in the designated area. Unless there is a sign prohibiting it, vehicles may make a right turn on a red light at a two-way intersection, or a left-turn leaving a one-way and entering another one-way road.

Malfunctioning Traffic Signals

If a signal is malfunctioning and displays a green or yellow light, vehicles may proceed with caution. If the signal is red or unlit, then the vehicle must stop and follow the rules as if there were a stop sign at the intersection.

References

• Oncle: Traffic-Control Signals - 75 Pa. Cons. Stat. § 3112