> In my experience, humans respond incredibly poorly to traffic lights being out.

My purely anectodotal experience is that the response is variable and culturally dependent. Americans tend to treat any intersections with a downed stoplight as a multi-way stop. It's slow but people get through. I've experienced other countries where drivers just proceed into the intersection and honk at each other. (Names withheld to protect the innocent.)

It seems a bit like the Marshmallow test but measures collaboration. [0]

[0] https://en.wikipedia.org/wiki/Stanford_marshmallow_experimen...

Where I'm from (a relatively rural country) they just get treated like give way signs you'd have on a country road, the larger road generlly has priority but as it's not clear they'd be more cautious too.

The problem is when one road is busy enough the other doesn’t get a “look in”.

Rural drivers will know to turn right and make a u-turn, but city drivers may not know that trick.

One could argue that it's "cultural", but California state law says this about the situation:

> Traffic Light Not Working

When a traffic light is not working, stop as if the intersection is controlled by STOP signs in all directions. Then proceed cautiously when it is safe to do so.

https://www.dmv.ca.gov/portal/handbook/california-driver-han...