Transportation is a complex system:
A number of cold weather American states are reporting their dismay at finding out that LED traffic lights are so energy efficient that they do not produce enough excess heat to dissipate any snow that covers them.
Oops. Maybe we can go back to these.
I knew that some northern cities were experiencing this for some time. What complicates matters is that the energy bill passed during George W. Bush’s time required that all traffic signals only have bulbs which met certain energy use criteria. LED are the only lights which meet this criteria.
Now, any roadway user who approaches a dark or inoperating signal is supposed to treat it like an all-way stop. I would suspect that is the case here as well. Additional options given to jurisdictions now include marking the edge of the back plate of a traffic signal head with a reflective yellow border. This will help identify a traffic signal location and whether or not it is operating.