During the severe weather season, it is not unusual to have power outages due to high wind or lightning strikes. Traffic signals throughout the city rely on electricity to function. If a traffic signal is in an area of a power outage, it will go dark.
If you approach a traffic signal without power, remember that the rules of right-of-way still apply. You should:
Slow down and prepare to stop.
Determine who has the right-of-way to proceed through the intersection.
If there is a lot of traffic at the intersection, it will naturally begin to function as a four-way stop. Remember that vehicles have the right-of-way in the order in which they arrive regardless of which road they arrive from. If two vehicles arrive at the intersection at approximately the same time, the vehicle on the left must yield to the vehicle on the right, and left turns must yield to oncoming traffic.
Always assume that other drivers may react unpredictably or that they may not even slow down when driving through an uncontrolled intersection. Drive defensively, even if it means waiting beyond "your turn" to proceed through the intersection safely.