You pull up to a four-way stop, and the light is red. No big deal. You take this opportunity to change the radio station, pick a poppy seed out of your teeth from your morning bagel, and wait. And wait. And wait. You've been here through half of a song already. Oh no, you realize. The light is stuck on red.
Can you go through? Can you turn right? Can you turn left, which is really the way you need to go? There are cars behind you now. Can they rat you out or will they go along with your lawbreaking ways? Most importantly, what's the safe move and is it the same as the legal move?
So many questions! If the lights are working properly in the other direction and cross traffic is still flowing in front of you, then the electromagnetic sensors embedded in the pavement most likely haven't recognized your car at the light. Those sensors often extend back a bit to detect when multiple cars are waiting, so if you're the only car at the light, that could be the issue. Usually you can see the lines in the pavement where the sensors are located. If you are the only car at the light, back up and drive over the sensors again. Engineers say it's worth a try, at least.
If that doesn't work and you decide you've waited long enough (and you're sure there aren't any other vehicles around), you can chance it and run the red light. But be aware: If you decide to be this daring, you can be pulled over and cited by an officer. If that happens, your best chance is to explain what happened; the officer may check out the light himself and see that you're correct. Or he may find that you were impatient and write up that ticket anyway.
However, if cross traffic isn't flowing either, both lights are probably malfunctioning. But in this case, it's more likely that the lights will be flashing — or completely dark. And then you should treat it as a four-way stop.
But what if you're on a two-wheeled vehicle? Motorcycles and mopeds run across this problem far more often, as sensors are usually set to detect four-wheeled, 2-ton (1.8-metric ton) vehicles. You've got a couple of choices here. You can look for the loops embedded in the road and roll back and forth over them and try to trigger the light's sensor. Or you can sit and hope that a heavier, easy-to-detect car comes up behind you and does it.
Those loops are electromagnetic, so strapping a powerful magnet to the underside of your motorcycle or moped might help trip those sensors. Maybe. Of course if you find it's the same light that's getting you stuck every time you ride to work, find another route with stoplights that are less persnickety.