Had an interesting drive home yesterday afternoon. Ended up on Sorrento Valley Blvd/Calle Cristobal heading east from Vista Sorrento Parkway to Camino Ruiz using 10.5, and it happened that every single traffic light on this road was off (meaning no flashing red - just off). Was a good test for FSD and also got it on GoPro (might post it sometime if I ever pull it off). There were 10 opportunities to test the behavior (10 intersections with traffic lights out).
I was driving away from the sun with the sun low in the sky at 4PM. So some of the traffic lights were well illuminated. Some were in shade.
For the traffic lights that were illuminated by the sun, usually the perception detected them as yellow, and just slowed down way in advance like the light was yellow. A tap on the accelerator seemed to override that and allowed me to proceed to the stop line. I did have to override at that point because then it would tend to go through as I recall.
There was one well illuminated light that seemed to be perceived as green. No evidence of slowing, so had to disengage for that. It just figured it was green.
For the non-illuminated shaded lights, the car seemed to recognize them (or map them) and saw they were out. For those lights, the car came to a stop pretty reliably. However, it did not treat the intersection as a four-way stop. It just stopped. And then I had to proceed manually (accelerator input was enough to get it going again, so not actually a need to disengage and re-engage).
I'll review the footage and see whether there is anything else interesting. One person had crashed off the road into a wall at an intersection. I'm not sure whether it had anything to do with the lights being out. FSD did better than that, I guess? Though it would have crashed without me at the wheel on that "green" light, I suspect (or at least put others at risk - obviously people were generally proceeding with caution, so they probably would've seen the FSD Tesla bombing for the 4-way stop intersection at 40mph if I had let it go).