Many automobiles use their front and rear signal lights to create hazard lights in a distinctive lighting pattern which can be used to alert other drivers to a problem. Typically, hazard lights run on the same circuit as regular lights, although they are controlled with a separate switch. Knowing how and when to use hazard lights can be useful in an emergency situation, although you should also be equipped with highway flares.

Hazard lights are actuated with a small switch located near the steering column. Usually it is in a separate area, so that the lights cannot be turned on accidentally by an unwitting hand. In many cars, the switch has a small triangular icon on it, and it is often red or orange, to make it more visible in emergencies. The two most common types of hazard light switches are tabs which need to be pulled, and buttons which are pressed.

When the switch is activated, all of the turn signals on the vehicle will simultaneously illuminate and start flashing in a rhythmic pattern. This pattern is highly visible and very unique, so that drivers will not confuse it with turn signals or approaching headlights. As a general rule, if you see a vehicle with hazard lights on up ahead, you should slow down until you know what the problem it.

Most commonly, hazard lights are used on a disabled car which has been pulled to the side of the road. Especially at night, they increase the visibility of the car so that it will not be hit. It also alerts drivers to the fact that there is a problem of some kind, and some drivers use hazard lights to ask for help, usually in combination with leaving the hood up. Responders to an accident scene may also use their hazard lights to warn drivers about unusual conditions up ahead, and to help clear a lane for the accident.

Driving should never be done with the hazard lights alone, as this can be highly dangerous. Hazard lights should also not be used to warn oncoming traffic about approaching hazards. A much better choice is flashing your headlights or lightly tapping your horn. Using hazard lights may distract or confuse the oncoming driver, while flashing your lights is generally interpreted as a sign to slow down and be cautious. Hazard lights can also be used to check whether or not your signals are using when your car is in a parked and safe position, such as your driveway. Turn the key to the “accessory” stage and turn the hazard lights on so that you can walk all the way around your car and make sure that no bulbs need to be replaced.