A Definitive Guide to Using Your Hazard Lights

Richard McCuistian, ASE Certified Master Automobile Technician

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on October 4th, 2024

Reading Time: 6 minutes
Summary
  • Activating the hazard warning lights causes the left and right turn signal to blink at the same time until they’re turned off.
  • It is necessary to turn your hazard flasher while you’re loading and unloading passengers, during a roadside emergency, or as a way of warning other drivers of upcoming road obstructions.
  • You shouldn’t turn on your hazard lights when driving in bad weather conditions because it won’t help other drivers know when you intend to switch lanes.
  • Hazard lights are powered by your car’s battery, which means they can drain the battery if used for too long. Because of this, it’s a good idea to only use your hazard lights for one to two hours.
  • If the vehicle in front of you has its hazard lights on, slow down and back away. Try to give them more space while staying alert just in case they suddenly stop or move to another lane.

You’ve probably used your vehicle’s hazard lights once or twice, maybe because of a flat tire or you’ve parked somewhere you’re not supposed to.

It’s easy to activate the hazard lights一all you have to do is press the button with a red triangle on it.

But does that mean you should use them as much as you like?

What are Hazard Warning Lights?

Activating the hazard warning flasher causes the left and right turn signal lights to blink at the same time.

In some vehicles, the hazard flasher has other functions, such as having dash indicators for the hazard system and audio signals indicating that the flasher is operating.

car hazard warning lights button red triangle activated
It’s easy to activate the hazard lights一all you have to do is press the button with a red triangle on it.
car hazard warning lights button red triangle activated

Hazard lights are also called parallel or variable-load flashers because of a resistor parallel with the contacts that provides a control load and steady flash rate.

What Are Car Hazard Lights For?

Hazard warning flashers alert other drivers that your vehicle is a temporary obstruction on the road and that they should be careful about getting close to your car.

When Should You Use Hazard Lights?

You can activate hazard lights anytime, but there are specific circumstances that make their operation legal. Here are the most common ones.

You Have a Flat Tire

It’s acceptable to have your hazard flashers on while you’re on the side of the road, changing a flat tire.

Your Car Has Broken Down

Another valid reason to have your hazard lights on is when your car has broken down, and you’re waiting for someone to assist you in towing your vehicle to the nearest repair shop.

A bad alternator, coolant leaks, and lack of gasoline are some of the most common reasons that could cause your vehicle to break down while you’re out on the road.

Another valid reason to have your hazard lights on is when your car has broken down, and you’re waiting for someone to assist you in towing your vehicle to the nearest repair shop.

Make sure your vehicle is free from any issues before going out for a long drive.

An Officer Pulled You Over

Flashing your hazard lights is a way of acknowledging a law enforcement officer’s signal while you’re driving. It also lets other drivers know you’re about to pull over to a location where you’re not causing any traffic.

Your Vehicle Is Part of a Funeral Procession

Although it’s not considered an emergency, a funeral procession is a common situation where drivers use their hazard lights.

It’s usually done by the last vehicle of the procession, notifying other drivers that traffic can resume once the vehicle has passed.

You’re Loading or Unloading Passengers

Picking up and dropping off your kid to school are some situations where it’s advisable to use hazard flashers, provided that you’re in the designated loading and unloading zone.

You’re Warning Other Drivers to Slow Down

Hazard lights can also be used to notify other drivers to slow down because of certain road obstructions, such as fallen trees, car accidents, live wires, and a landslide.

Legitimate Emergencies

There are emergencies where can activate your hazard lights, such as transporting a person with health issues when an ambulance is unavailable.

Under this circumstance, you’ll need to create a safe exit from traffic, and using your hazard lights can let other drivers know that you have an emergency.

When Not to Use Hazard Lights

Some drivers use their hazard lights even when they’re not supposed to. Below are some circumstances where you shouldn’t use hazard flashers.

You’re Parked Illegally

Don’t use hazard lights to get out of a potential parking ticket, as they tend to act more like a beacon to attract law enforcement officers.

Driving Under Inclement Weather Conditions

Hazard flashers can do more harm than good when you’re driving in bad weather conditions. Because both signal lights are blinking at the same time, other drivers won’t be able to tell which lane you’re about to go to.

Hazard flashers can do more harm than good when you’re driving in bad weather conditions.

When driving during a heavy storm or blizzard, it’s best to use your headlights and tail lights instead until the weather clears up.

Driving In Heavy Traffic

Using your hazard lights won’t get you out of heavy traffic. It’ll only confuse the drivers behind you because you won’t be able to use other turn signals.

State Laws and Regulations on the Use of Hazard Flashers

Laws regarding the use of hazard lights can vary per state. Some states allow drivers to use them while the vehicle is in transit, while others don’t, and several states permit the use of hazard lights but only during emergencies.

Improper use of hazard lights can even cause the driver to face charges. For example, if a crash is caused by a vehicle that had its hazard lights turned on, the driver can be held liable for the victim’s injuries and other damages.

States that permit the use of hazard lights while driving States that prohibit the use of hazard lights while driving States that permit the use of hazard lights during emergencies
Alabama Alaska Arizona
Connecticut Florida Arkansas
Georgia Hawaii California
Kentucky Illinois Colorado
Michigan Kansas Delaware
Mississippi Louisiana Idaho
Missouri Massachusetts Illinois
Nebraska Nevada Iowa
New Hampshire New Mexico Minnesota
New Jersey Rhode Island Maine
New York Tennessee Maryland
North Carolina Wyoming Montana
North Dakota Puerto Rico Ohio
Oregon Oklahoma
Pennsylvania Virginia
South Carolina Washington
South Dakota West Virginia
Texas Wisconsin
Utah
Vermont

How Long Can You Leave Hazard Lights on in a Car?

Hazard warning lights should only be used when the vehicle is stationary. As you change your tire or address other pressing issues with your vehicle, you should keep your hazard lights on. Only turn them off once you’ve resolved the issue and no longer pose a hazard to other drivers.

If you’re driving, you should only turn your hazard lights on momentarily. Five seconds should be enough for other drivers to notice.

Do Hazard Lights Drain Your Battery?

Hazard lights are powered by your car’s battery, which means they can drain the battery if used for too long. The amount of time it’ll take before they completely kill your battery will depend on several other factors, such as the age of your car battery. Some car batteries will die after a few hours of having the hazard light on, while others can last overnight. Because of this, it’s a good idea to only use your hazard lights for one to two hours.

What To Do if Someone Has Their Hazard Lights On

If the vehicle in front of you has its hazard lights on, slow down and back away. Try to give them more space while staying alert just in case they suddenly stop or move to another lane.

If the vehicle has stopped in the middle of the road and is holding up traffic, consider calling the police for help. They can help the driver pull over safely and guide motorists to get traffic moving again.

How Much Do Hazard Lights Cost?

The exact price of hazard warning flashers can vary depending on several factors, such as your vehicle’s year, make, and model. In general, however, you can expect them to cost anywhere from $10 to $130.

Key Takeaways

Don’t use hazard lights carelessly. They’re not meant to get you out of tickets and heavy traffic.

Improper use of hazard lights can create even more traffic because they can confuse other drivers. In some cases, you might even be held liable for certain accidents.

So use hazard lights only for emergencies and to alert other drivers to steer clear of your path.

Lastly, it pays to understand state regulations regarding the use of hazard flashers to avoid any problems with law enforcement.

Where to Get New Signal Lights for Your Vehicle

The hazard lights are used to communicate with other drivers, making them a crucial component to maintain safety out on the road. So, if your signal lights are starting to dim, it’s in your best interest to look for high-quality replacements as soon as you can. Thankfully, CarParts.com has an array of selections for you to choose from!

Our website makes it easy for you to find lights that fit. We designed it so everything’s as user-friendly as possible. This means everything you’ll ever need is one click away, and you can even use your mobile devices to check out our catalog. Not only that, but we have a built-in vehicle selector that lets you input your car’s year, make, and model to only show lights that fit your ride’s specifications.

Our delivery process is equally as trouble-free since we have warehouses strategically located across the country. This means you can expect your order to arrive in as early as two business days.

Don’t run the risk of causing accidents by driving with faulty signal lights. Shop and get the best deals on automotive lights today!

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician