Driving back to the Twin Cities (Minnesota, US), from a neighboring state, there was a severe rainstorm in process the entire time - near hurricane conditions. As in - there was low visibility due to the heaviness of the rainfall itself, not because of fog or anything.

Relieved to finally reach the outer limits of the cities, suddenly several cars around me had their hazard lights on!

My experience with hazard lights has been that one puts them on if pausing in a lane momentarily (to tell the drivers to go around), things like that. But not to be used while in motion.

I mean, it was easier to see the cars I guess through the heavy rain (vs just headlights/high beams). But since it was impossible to know when the driver in the next lane was going to move into my lane, and in the freeway system people are always changing lanes, I feel like it was negative overall.

Is there some signal or safety-aspect that I am unaware of?

  • 2
    Some places recommend (or require?) them if the speed is significantly slower than the speed limit or the expected speed (though in the described weather conditions the expected speed should probably be much lower); some places also have confusing guidelines on the use of fog lights (and the awareness of fog lights in non-foggy areas is also a problem?).
    – xngtng
    Jan 1, 2023 at 20:31

1 Answer 1


Like xngtng, I had always thought that turning on your hazard lights was permitted when you're driving significantly slower than the speed limit because of weather conditions or your car is breaking down or running out of gas. Or you've stopped somewhere like a no parking/stopping zone or just on a street briefly to do something like answer your phone or look up directions. I learned to drive in Ohio and then lived in California for many years.

I found an article from 2016 in the Atlanta Journal-Constitution newspaper that lists what's permitted in each state. Note: Information may have changed since 2016. I'll excerpt the Minnesota statement.

Minnesota: Hazard lights are not permitted while driving except to indicate a traffic hazard.

Most states have the same requirement--not permitted except for a traffic hazard. What exactly constitutes a 'traffic hazard' is another question.

  • 2
    a 'traffic hazard' would be e.g. complete stop of traffic on a highway
    – Vickel
    Jan 1, 2023 at 20:53
  • 4
    @4dcndn Well, you shouldn't change lanes while having the hazards on, but of course, people never do what they should do on the roads.
    – xngtng
    Jan 1, 2023 at 22:12
  • 3
    In France it is customary (not sure if it’s a legal requirement) that if there’s a sudden slowdown you turn your hazard lights on until the car behind you has slowed down (and turned their hazard lights on). The goal is to avoid pile-ups. Even though the official name of those lights in France is “distress lights” (feux de détresse) they are colloquially called “warning lights”.
    – jcaron
    Jan 1, 2023 at 22:17
  • 4
    @jcaron Same in Germany. People turn on the warning lights if they have to slow down significantly (say <30 km/h outside of a city) or may have come to a complete stop, particularly when reaching the tail of a traffic jam. However, once inside the traffic jam, with cars behind you that are no longer in danger of running into you, you turn it off again.
    – Bergi
    Jan 2, 2023 at 4:39
  • 5
    @Mr47 In the United States, I have never seen a car where the turn signal would override the hazard lights.
    – DoxyLover
    Jan 2, 2023 at 11:08

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