How Emergency Vehicle Lights are Used

Warning lights on emergency vehicles signal to other motorists to clear a path for the fast-moving first responders. Law enforcement also use light signals to instruct a vehicle to pull over.  Other colors and variations of lights may indicate construction and slow-moving utility vehicles. To understand more about the colors and use of emergency lights, here is a list of generally mandated colors and uses of emergency lighting.

The general color code for emergency lights

While the stipulations vary from country to country, the list below provides an overview of emergency light color usage in the United States:

• Red: Forward facing red lights are virtually always present on emergency vehicles such as fire trucks, ambulances, and police cars.
• Blue: The color blue is most often used by law enforcement. A few other organizations are permitted to use blue lights to include tow trucks or other utility vehicles in states such as New Mexico and Texas.
• Amber/Yellow: Non-emergency vehicles used for construction, road maintenance, funeral escorts, and car towing make the most use of yellow or amber warning lights. Vehicle which stop frequently or must travel slowly may use this color warning light.
• White: Each state may mandate the use of this optional color warning light in different ways. In some states, white light is only permitted for use on first responder emergency vehicles. Typically, white light must be used in conjunction with other color lights, particularly when installed in a light bar.
• Green: While green light is used in some states by volunteer firefighters, paramedics, and a few other agencies, this color has been most commonly associated with Homeland Security following the terror attacks on 9/11. Homeland Security vehicles will patrol a given area with green lights illuminated to increase visibility.

How do different emergency vehicles use their warning lights?

Below are three main emergency organizations and their general use of emergency lights:

• Police Officers: Solid red, solid blue, or a combination of the two distinguish law enforcement officers on the road. Some officers use amber or white lights; however, these lights are generally configured to face the rear of the vehicle. These amber lights are often in the shape of an arrow. Some states allow for “special police,” (typically humane society agents who work security positions for universities, hospitals, etc.), to use the same colored lights as authorized state police. “Special police” receive specific permissions from state law enforcement.

• Firefighters and EMS: Red and white lights tend to illuminate from fire trucks (and other firefighting entities’ cars such as the fire chief’s vehicle), ambulances, and other emergency medical transports. Like with police cars, most optional colors on these emergency vehicles face the rear. One of the few exceptions include fire trucks in Chicago where green lights are installed on the starboard side as a part of nautical tradition.

• Volunteers: Many states permit the use of emergency lights on the vehicles of EMS and firefighter volunteers. However, each state stipulates the specific use and color of emergency lights for volunteers so as not to confuse other motorists. It is important to know the laws of each individual state prior to purchasing expensive lighting equipment.

Warning lights exist for your safety

For the safety of all motorists, it is important to understand what different lights signify and who is permitted to use them. The color code helps other drivers understand what fast or slow-moving vehicle is before or behind them so they know how to react conscientiously. Verify the laws in your state if you wish to install emergency lights on your vehicle to be certain you are upholding the law and using your lights safely.