It’s the first day of summer and the likelihood of severe weather—and associated power outages—becomes more prevalent.
That's why safety officials are reminding residents that traffic signals rely on the same electrical grid for power, and therefore it is not uncommon for traffic signals to go dark when the power goes out.
Heavy rains or lightning strikes can also damage the electrical circuitry of traffic signals, causing them to malfunction and go into flashing mode.
When traffic lights go dark—and/or flashing red—drivers sometimes make mistakes, to put it diplomatically.
Here are a few rules county officials say can prevent a crash:
- Signals flashing all red lights: When drivers approach a signal light that is flashing red, they must come to a complete stop. Always make sure that it is safe to proceed before entering an intersection, as the crossing traffic may not be required to stop.
- Signal flashing red and yellow lights: There is no need to come to a stop when approaching a flashing yellow light, but be alert for drivers entering and proceed with caution. Follow the same rules as any two-way stop intersection, including yielding to oncoming traffic when turning left, and yielding to pedestrians in crosswalks.
- Signal lights all dark: When a traffic signal is completely unlit and no stop signs are present, and the signal lights are not wrapped in cloth or other material, the intersection legally becomes an uncontrolled intersection. As with any uncontrolled intersection, the rules of right-of-way still apply.
If approaching a signal system without power and the lights are not covered with cloth:
- Reduce speed and prepare to stop
- Vehicles have right of way in the order in which they arrive
- When arriving at the same time, the vehicle on the left must yield
Proceeding on a solid red light is always illegal and can lead to a serious crash. Be alert, and make sure that the light is still flashing red and that it is safe to enter before entering the intersection.
During power outages, Hennepin County often receives requests to install temporary stop signs at signalized intersections that are without electrical power.
During widespread power outages, this problem becomes magnified because of the number of intersections affected. Also, when power is restored, a conflict could exist between the stop sign and the green indication of the traffic signal system unless the controller has been reset to the “red flash” mode.
Setting the controller to red flash mode prolongs the traffic problem because the signal cannot resume normal operations when power is restored, and taking a traffic signal out of red flash mode carries numerous risks to traffic safety.
Who to Contact When Stoplights Go Out
To report a signal malfunction, contact the highway department responsible for the signals.
For signals on state highways in Hennepin County, contact the Minnesota Department of Transportation at 651-234-7500.
For signals on county roads, contact Hennepin County Public Works at (612) 596-0300
If the malfunction is an emergency, dial 911.