Why Are Emergency Lights Red and Blue?

Have you ever been riding along with a friend or family member when you suddenly see red and blue flashing lights behind you? A quick glance behind you will tell you what kind of emergency vehicle is approaching.

Is it an ambulance? Perhaps a fire truck? Hopefully it's not a police car about to pull you over for speeding! Regardless of what type of emergency vehicle it is, it's important to pull over to the side of the road, so that it can pass safely to get to its destination as quickly as possible.

Emergency lights serve several important purposes. First, they visuallyconvey the urgency of an emergency vehicle's journey. If an ambulance is heading to the scene of an accident or from an accident scene to a hospital, its emergency lights alert other drivers of its presence, so that they can maneuver out of the way.

At other times, an emergency vehicle may be parked near the scene of an accident or other dangerous location. Emergency lights notify drivers that there is a problem in the area, so that they can detour around it or slow down and take extra precautions while in the area.

Finally, there are those times when you've done something wrong, such as speeding or failing to obey a traffic signal. At these times, emergency lights in your rearview mirror let you know that a police officer wants you to pull over, so that your moving violation can be discussed.

There are many different types of emergency vehicles around the world. The types of emergency lights they use can vary widely from country to country. Emergency lights can even vary widely from state to state and city to city within a country.

For example, in much of the United States, early police cars featured only a single, non-flashing, red emergency light at the front of the car. The choice of red probably resulted from the fact that the color red is associated with stopand warnings in the U.S.

Over time, police cars and other emergency vehicles began to use flashing emergency lights. They also began to add another color: blue. In many areas, flashing red and blue lights are the standard emergency lights on many vehicles, although certain jurisdictions still choose to use other combinations or particular colors for certain types of emergency vehicles.

Since the use of emergency lights can vary greatly from state to state, it's difficult to tell exactly why certain color combinations are chosen. However, there are a few theories about why red and blue lights seem to be the most popular.

For example, while the color red is associated with stop and warning, red emergency lights can get lost in heavy traffic because of the fact that most tail lights are also red. In these situations, blue lights really stand out and help to alert other drivers.

Others point to studies that indicate that red lights may be more visibleduring the day, while blue lights may be more visible at night. Using a combination of flashing red and blue lights thus helps to alert drivers regardless of the time of day.

Finally, some experts believe using both red and blue lights alleviates problems associated with drivers who are colorblind. People who have trouble seeing red often have no trouble seeing blue. Likewise, drivers who can't see blue can nonetheless see red. Using both red and blue lights thus helps to alert all drivers, even those with colorblindness.