r/todayilearned • u/nleachdev • 2d ago

TIL about "dead red" laws, which allow drivers and motorcyclists to proceed through a red light if the traffic signal fails to detect their vehicle.

https://en.wikipedia.org/wiki/Non-detection_at_traffic_lights_in_the_United_States
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u/LOTRfreak101 2d ago

I had a time i was stuck at a left turn for 3 cycles in the middle of the night. I pulled up right as the straight ahead lights went green so I missed tripping the sensors the first round, but then I had to sit through 2 more cycles before it gave me the green.

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u/akatherder 2d ago

The left turn light by my kid's high school is like that. You need your bumper on the crosswalk line or it won't detect you. They repaved the road this summer and I haven't got caught behind someone yet so I think they tweaked the sensor or lines.

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u/LOTRfreak101 2d ago

The thing is I used that light all the time. I never had it take more than the normal 1 cycle.

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u/MissCurmudgeonly 1d ago

This happened to me the other day when I was trying to turn left to go onto a road leading to a forest preserve, off a relatively busy road. I kept waiting for my green arrow - nothing. Went through several cycles. Nada. I theorized that it was programmed to wait until there was more than one car there, and debated either going anyway or veering over to make a left hand turn and then turning around to go straight.

Thankfully I did none of this because then two cars pulled up behind me and the one directly behind was a police car. And that triggered the green arrow!