Warning: You May Be Using Your Hazard Lights Incorrectly

Living in a congested city like San Francisco exposes me to a lot of creative driving and parking techniques.  But one that’s always irked me is when people double park and put their hazard lights on, as if that somehow makes it legit.  I get that San Francisco is high on cars and low on parking spots.  But blocking traffic so you can run in to get a scone?  Come on! 

I know hazard lights were created to, well, alert other drivers of hazards, but seeing them used for so many other purposes has me confused. 

When is it actually okay to use hazard lights? 

It turns out the answer is more complicated than I thought.  Of course, if you’re parked and need assistance, it’s okay to turn them on.  But what about when you’re driving?  As with most laws, it varies by state. 

In some states, you’re free to drive with your hazards as you see fit.  In others, it’s not permitted at all.  And some states permit it if there’s an emergency or a hazard on the road that you want to make other drivers aware of, like a rockslide. 

One common exception, even in states that don’t otherwise allow hazards, is funeral processions.  Some states also consider bad weather to be cause for hazard lights, but there’s debate as to whether this behavior should be encouraged. 

Should you use your hazards in bad weather? 

Though there’s no definitive right or wrong answer (unless it’s illegal in your state), there are some things to keep in mind.  Your hazards may make you more visible in the rain or snow and alert other drivers that you’re traveling below the speed limit.  But they may also put you at risk. 

In some cars, turn signals are disabled when the hazards are turned on.  And even if they work, it can be hard to distinguish a turn signal from a hazard light.  If drivers can’t anticipate your next move, your accident risk could increase. 

Another issue with using your hazards is that it may cause confusion for other drivers.  Most people expect to see hazards when there is a specific danger to look out for.  If drivers are busy looking for a hazard or slowing down in anticipation of one, it means they may be taking their eyes of the road, as well as disrupting the flow of traffic. 

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About Jessica Guerin

During her time as senior copywriter at Esurance, Jessica wrote about everything from automotive trends to insurance tips to driving dogs (it’s a thing!).  In her free time, you can find Jessica hiking with her dog (who cannot drive), devouring a good mystery, or very slowly learning Spanish. 
View all posts by Jessica Guerin →

Driving down the road with your hazards on for no apparent reason is not legal and there is a lot of people in south Florida who do this.  That is not what the hazards are for, If you are a hazardous driver then gt off the road and leave it to those who know how to drive safe. 

Lynn, After 30 years as an EMT, I have to say that is one of the most ignorant things I've ever heard a nurse say.  It isn't about speed, but delivering emergency care to both the woman and the child.  Not to mention having a distracted driver and a woman in pain sharing a drive is a great recipe for an accident or a bad joke.  You forget about offering pre hospital advice and I'll refrain from badpan and sleeping pill analogies. 

If your Wife is having an Emergency, Call an Ambulance and Meet it someplace close if you think you just HAVE to go now !  Never Drive with your Emergency Flashers on, You are not an Authorized Emergency Vehicle.  Even Ambulances are NOT aloud to Speed to get somewhere, their Lights are so Traffic will Yield to the Ambulance as per the Law.  You are Risking your, your Wifes, and others lives thinking YOU can Transport a Sick or Ill Loved one "Faster" to the Hospital.  Ambulances have Medical Personal that can Begin Treatment, you Can't Ambulances have a Driver and a Separate Medical Attendant, You can NOT do the two things at the Same time. 

I have driven a 18 Wheeler for 42 years.  I turn on my "Hazard Lights" when I am climbing a hill or mountain at 15 mph less than the "Posted Speed Limit" on the road.  I do this with the hope that other drivers will see my "Hazard Lights" and not strike the rear end of my semi-truck.  I do this both day and night.  With so many drivers either texting or talking on their cell phones while driving, I would like to make my semi-truck as visiable as possible to the vehicles approaching from the rear!!! 

I also drive a semi-truck.  Actually it's a Federal Motor Carrier regulation that you must remain in the right lane and use hazards when traveling 25 miles under the speed limit where the flow of traffic is not impaired.  It's not an "unwritten law" or just a courtesy.  In fact it's posted on some interstates in mountain areas.  But needless to say, trucks are governed more by the FMCA than state laws. 

When a truck driver passes a car on the left and wants to get back over in the right lane, is the proper thing for the car to do is flash their lights to tell the truck driver that's it's ok to get back over ? 

I'm with you on this one!  I have also used them in rain where you could NOT see the road very well, as in driving rain.  Did this in AR once only to find once the rain let up I had a couple miles of vehicles following me.  This was the same day Arkadelphia was hit by tornadoes. 

And after being the trucking safety industry for many years, Mike's response is what many drivers do, however, it's wrong.  Hazard lights are for when the vehicle is pulled over.  When climbing a hill drivers like to think they're showing the little cars they are really slow.  If a car driver misses seeing a wall ahead of them 13 feet high and 9 feet wide moving slowly, two small blinking lights are no help.  A common error. 

Here in NYS the Thruway has signs alerting you to put on HAZARDS if you are driving slower than 45mpm.  In Italy, on the autostradas, you put them on when you come upon a back-up that is really serious and you are alerting those behind you that YOU BETTER HIT THE BRAKES NOW!  and be prepared to STOP IMMEDIATELY.  Italy has this habit of building high-speed roads with blind-curves and hills that block your view until it's too late.  Of course, Italian drivers only addd to it by speeding. 
Personally I use the HAZARDS whenever I feel it's needed.  I'll worry about the ticket later if I live. 

Even without low visibility situations like blind turns, it is difficult for drivers to determine whether a car in the distance has its brake lights on because the driver is gently tapping them or has used them to stop.  When traffic stops on the freeway, or at an exit, I turn mine on to let the cars behind me know that I am stopped and they need to start slowing NOW to avoid rear-ending me. 

Those 200-plus car pile ups?  They happen in fog.  The yellow of the hazard lights travels much farther than taillights.  Huge increase in visibility from the rear. If I am driving to conditions in fog those hazards go on immediately because there is always someone coming up from behind driving faster than visibility warrants, either because they know the road better or because they scorn to let weather slow them down. 

I've spent many years living in many countries and this piece reminds me of Germany.  In Germany, where high speeds are common, when cars slow down quickly for whatever reason, they turn on their hazards briefly until approaching cars behind them are aware or they have passed the hazard. 

It has certainly saved my hide from a nasty accident.  I wish this was practiced here in the US. 

I have never lived in Germany although I hope to some day.  I do this out of habit also, seems like common sense.  Also turn them on in school zones or when following a bus dropping kids off.  Having driven commercial vehicles you learn that communication with other drivers is very important.  If you drive a large vehicle that other drivers can't see around or through you need to make those behind you aware of danger ahead.  Of course that doesn't mean they will heed your warning.  Most likely they will just put on their turn signal (or not) and go flying around you only to have to slam on the brakes realizing then that you were trying to tell them something. 

I am certainly appreciative of Truckers/trailer-towing vehicles that use Hazard Lights when crawling up steep +/- mountain passes, such as I-5's "Grapevine" or I-80's Donner Summit, especially in heavy rain, fog or snow.  Sometimes you can't see them (as large as they are) due to sudden heavy downpours, road mist, sudden dips in the road that are filled with mountain runoffs.  Also, I have had to use them late at night on a two-lane mountain road when my car started to lose power and my headlights suddenly died, and there was no space to turnout for miles due to the terraine.  Really, really scarey!!!!!! 

Interstate 5 through the Sacramento Valley and San Juaquin Valley of central California has the TULE FOG that can cut visibility to ZERO in an instant!!!!!  I once was following about a half to 3/4 miles behind a convoy of semi-truck/trailers when they all disapeared into the curtain of Tule Fog.  When I got to that point in the road I suddenly could not see past the hood of my car nor the fog-line at the right side of the lane.  Immidiatly put my HAZARD's on and slowed down until I could safely pull off. 

Laughing at all the lame-brained states that think it's NEVER appropriate.  Seriously?  NEVER?  Somehow I'm sure those laws are ignored by off-duty cops in their personal vehicles, every time they're in a hurry and don't want to obey any other traffic laws either! 

Betty you do not have the right to be the speed police Just stay out of the left lane unless passing, You will only irritate the driver that you are obstructing if you turn on your blinkers and remain at the posted speed Relax and enjoy life without trying to control other drivers! 

Charles, You are Totally Incorrect !  It is NEVER Legal to SPEED !  NEVER !  Because Ten People Speed does not make it Correct, YOU are Breaking the LAW !  Drivers are to Drive AT or below the Posted Speed Limit, and to Keep Right if they are Slower than "Regular" Traffic.  But if Traffic is Driving 75 MPH in a 65 MPH Zone, they ALL are Breaking the Law, not someone who is Driving 64 MPH.  The Selfish Attitude of some Drivers thinking the LEFT Lane is for People to Speed in and Pass Everyone is one of the Major Causes of High way Traffic Fatalities.  What's the Big Hurry?  Why are YOU more important that all the other Drivers?  Yes if you want to drive slower than the Posted Speed Limit, you should avoid the Left Lane, but by no means, or any fraction of the Law, is someone doing Slightly Less than the Posted Speed (LIMIT) Breaking any Law or Rule!  Perhaps you and others should look up the word (LIMIT) in the Dictionary, and try to grasp it's meaning.  The object is to Arrive at your Destination ALIVE, not be the First one to the Morgue.  Somebody Loves you, slow Down and Live longer, enjoy the Ride ! 

As Traffic Officer in CA.  People that put on their hazard lights while parking illegally only makes then easier to spot.  As if it some how gives them permission to park in a red zone or tow away zone.  then they come back to their car perplexed that they have a hefty parking ticket for being lazy and not finding legal parking.  Never fails to amaze me. 

Just happen to use my hazard lights last night in a situation where I could not pull into the driveway because of a 6-8 inches of snow and did not want to get stuck, cause I KNOW I will.  so I was half on road and half in snow to have a somewhat traction to leave after picking up my daughter and it was night time on a side street.  Just wanted other cars to know to be careful and go around me.  Was that illegal?  Just wanted to be safe and not get stuck.  Should be a safety issue to use, not abuse it

You are mistaken, regarding one state: in Delaware it is MANDATORY to use your hazard flashers in a funeral procession.  I was one of the funeral directors who sucessfully got this bill through the Legislature working with the Delaware Funeral Director's Association way back in 1998. 

Hi Gang, I live in Fla? ' n I always click on my Flashers as a warning, when ever I back into,or out of a parking spot, I always try to back in to a parking, cause it seems, when ever I come out of the store, Mall, where ever, There is always a large SUV or Truck parked next to me, if I have to back out, I have to back Half the length of my car til I can see clearly right or left, When I pull in, I can see Ped's, it's much easier to back in, 'n when I leave, it IS MUCH Easier to Drive Straight out, can see left 'n right perfectly.  Stay Safr Kids
Larry