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Proper use of hazard lights

When are you supposed to use hazard lights? I was under the impression the answer was:

Any time there is a unique limitation to your vehicle’s operation that may pose a hazard to other motorists.

It has come to my attention that the State of Florida (and perhaps others) have, as law:

Only when parked.

This flummoxed me! I was reminded of the advantages of hazard operation this night: I was transporting a 1"X4’X8’ Glass table top, with matching glass-and-brass legs…a real Boogie Nights setup. I was following the new owner thereof, slowly, as he served as “pilot car,” making especially careful turns (well clamped to the “A” frame, but ya never know…)

So, some FnF wannabe slides in between the two vehicles and acts a fool…until deciding to ZOOM around and make the right turn 1/8 mile onward. This is a PERFECT example where both of us “should have” used hazards: not only would it have communicated a “unique limitation to vehicle operation…”, it would have identified us as a convoy, probably saving FnF, and us, some stress.

Additional cases where I’ve used hazards: transporting passenger in open pickup (unique limitation of 35MPH, regardless of PSL), ascending a hill, heavy and slow. Heck my state has AS LAW to use hazards <40 MPH (written when the PSL was 55…so realsitically, use 'em @ PSL-15.)

Finally, USPS delivery drivers are REQUIRED to run with flashers on while delivering, meaning that they cannot comply with both federal and FL state laws simultaneously?!?

What say you? When can you use hazards? When do you? When should you?

Only when stopped is the correct answer here in Colorado. I instructed school bus drivers here and flashers were to be used when stopped on a road or at a rail road crossing.

I use hazard warning flashers every time I’m in or come upon any situation that would not normally be expected by other drivers and might be hazardous. That includes coming upon the rear end of a long line of stopped or barely-moving traffic… I like to warn the guy that comes up behind me that there might be a bad situation… just in case he’s tired, or has had a few beers, or is busy trying to upload his address to his car’s computer. That includes the ladies too. Just today one young woman drifted across the lines into my lane. I beeped, looked over, and she was texting. If I’d not been paying attention I’d be in some ER somewhere.

I would rather use my flashers one time too many than one time too few. I prefer to err on the side of safety.

I should probably clarify too that in NH the roads are full of curves, trees, and visual obstructions. Drivers come up on things very quickly. When, after driving for three years in North Dakota, I finally came home, I almost had to learn to drive all over again. In ND you can see things 16 miles before you come upon them. In NH you can see things 16 milliseconds before you come upon them. It’s a whole different driving environment.

Yeah I’m with the same mountainbike. When stopped or when coming upon something hazardous to warn others about. Particularly in snow or rain where either cars have slowed to a crawl on the freeway, or there has been an accident, emergency vehicles, etc. If I run across a herd of deer, I’ll throw the flashers on. Sometimes just flashing your brakes provides a warning enough so just depends.

Those laws must have some reason for being, but it isn’t obvious. I haven’t seen anyone driving with them on except in the sort of unusual situations some of you described, where they would be very helpful to other drivers. I appreciate the warning, even if lawmakers don’t.

Courtesy of The AAA, here is a summary of regulations, listed by state, regarding the use of hazard warning lights:

While my state is one of those that prohibits the use of these warning lights “while driving”, I have used them many times over the years on highways, in order to give traffic in back of me an extra bit of notification that there is an accident or other stoppage ahead, and to slow down NOW.

On the topic of hazard warning flashers, I believe that there is a certain percentage of the population that isn’t even aware that their cars have this feature. Several times each week, I will see cars parked on the shoulder of high-speed expressways–sometimes perilously close to traffic–with just a directional signal flashing. If these people perceived that they should turn on some kind of warning light, shouldn’t they understand that the 4-way flashers are much more appropriate in that type of situation than the directional signal? We can never get into the thought processes of other people, but I tend to think that these dim bulbs don’t even know that their vehicle has hazard flashers, or perhaps they never learned where the switch is located, or perhaps they have a thought process similar to the person whom I describe in the next paragraph.

Back in the early '90s, I was helping to “jockey” somebody else’s two cars around in Manhattan, and because I had to double-park for a couple of minutes, I activated the hazard flashers on this guy’s Chevy Celebrity. When he returned to his car, he threw an “almost” fit when he saw that I had activated his hazard flashers. In discussing the issue with him, it turned out that he believed this to be a “one-time” feature, sort of like a road flare, I guess. In other words, he thought that because I had activated this hazard flashers, he would never be able to use them again. Yes–some people really are that dense.

While my state is one of those that prohibits the use of these warning lights "while driving"

I bet if you got stopped for using your hazards while driving to communicate a danger to other drivers, you could challenge it on constitutional grounds. Freedom of speech, and all that.

It’s been done before (successfully) with flashing headlights to warn of speed traps.

According to that AAA list, about 12 states prohibit use while driving, the rest are split about evenly between allowing it or allowing it if there’s an emergency or traffic hazard. No consistency…

I checked the link and my state allows driving with emergency flashers unless otherwise posted. I have never seen this posted. Why would it be?

I have seen more than one Youtube video of Japanese drivers giving ‘one flash’ of the hazard lights to indicate ‘Thank you for letting me merge ahead of you in your lane.’

VDCdriver - Very helpful link, but it didn’t go into enough detail. Here in NY you are required to use you hazards under 40 on the interstate, Pennsylvania it is also required under 40 on the interstate and under 25 on the state highways ( I found out by getting a written warning for that ). Also in PA I stopped to see if a disabled tractor trailer on a very long 4 lane bridge needed any assistance and we both had to talk a trooper out of giving us a ticket for stopping on a bridge.
The trooper was of the opinion that the other driver should have coasted off the bridge before he stopped. He only let us go when I pointed out the bridge was going uphill.

I use my emergency blinkers (hazard lights) whenever I pull off the road for an emergency of some sort. I also use them when driving slower than usual or when it’s foggy. I could care less how a state words their “proper” use.

The only thing I’d caution about using them while driving is that its very hard at night, or in snow or fog, to judge where the heck a vehicle is with the flashing lights. I have seen trucks that have trailer lighting problems going down the road mile after mile with the flashers on. You’re looking at the flashers and waiting to come upon them but they just keep staying off in the distance. When conditions are bad, I don’t like people indiscriminately flashing their brakes or putting the flashers without a clear and present danger up ahead.

Funny this subject comes up today.

Yesterday I was hauling a car to my shop about 45 miles away. It was a misty, wet day and because I was in the Milwaukee area for half the trip…during rush hour…I decided it would be best that I leave the emergency flashers on, on the car that was on the tow dolly.
I was concerned that someone would be in a rush and not see the rear end of the car being towed.

People are impatient though, because I had no less than four cars pass me using the bike lanes or “right turn only” lanes. And I was able to keep up with traffic pretty good too.
I was a nervous wreck until I got out of the city.

I’ll admit though that all of this frustration was my own doing. I left the shop with the dolly about noon and would have had the car loaded and on the road by 1:30, but there was a hitch.
I got 15 blocks away from the car to tow, and recalled that I forgot to load the bag with the tire straps in it. So back to the shop, grab the straps and back to the car and I was loaded and on the road by 3:30. I couldn’t believe I had forgotten the straps.


I’m with missileman on this issue. I’ll use then whenever I feel it’s necessary for safety and I don’t care what the “rules” are.
I had a throttle cable break on my motorcycle long ago and was stuck with an idling engine. I was able to limp home by turning up the idle speed adjustment to a fast idle. This allowed me to go 20-30 mph on the shoulder of the highway. This was one of the situations I turned on the emergency flashers.
If you have a good reason for using them, it would take a real Barney Fife on a power trip to ticket you for using them even if it is technically not legal.

I’m in the same camp as missileman and B.L.E.
I have used my hazard lights in potentially dangerous on-road situations at various times over the years, and I will continue to use them.

Yes, my state (NJ) does prohibit hazard flasher use except when parked, but the probability of getting ticketed for using them as I do is probably extremely low, and as B.L.E. implied a cop would likely only take out his ticket book for this “offense” if he was really desperate for meeting his quota.

People tend to fear being penalized for “offenses” that are rarely–if ever–enforced. A good example of this is the statute in NJ which says that only gas station attendants are allowed to pump gas. For the nervous nellies who tell me that it is “illegal” to pump your own gas in NJ, I always give them this challenge:

Find even one instance of somebody being…detained…ticketed…or arrested for pumping his own gas in NJ.

Clearly they can’t find even one instance, because it has never happened. Yet, the vast majority of NJ drivers cower in their cars like mindless sheep while gas attendants decide how much gas to force into their tank and dribble down the side of their fender. I refuse to be one of those sheep.

@VDCdriver … Oregon has this law as well and I was threatened with arrest if I didn’t stop pumping gas into my rental car. I let the attendant take over but I highly doubt that I would have been arrested. Since I was on vacation…I let the attendant have his way.

@missileman–I can’t speak to the statutes in Oregon, but the one in NJ pertaining to gas pumping by attendants does not specify any penalty for pumping your own gas. It merely states that the process is supposed to be done by station attendants.

Not only has nobody ever stopped me from doing my own gas pumping, most of the time the attendants thank me for doing it. At the Costco station–which is where I buy 95% of my gas nowadays ($2.55 per gallon yesterday!)–I wave my receipt in the general direction of the nearest attendant, and he almost always shouts something like…Thanks, you’re good to go.

I pumped all of my gas in NJ when I was attending the NCO Academy at McGuire AFB. It may have had something to do with station being on the base. I can’t speak to the statutes of Oregon either because I was just on vacation there. I try not to “rock the boat” if I don’t have to.