Why Are Emergency Lights Blue and Red?

Photo by Lawrence Hookham

Originally Posted On: https://week99er.com/new/why-are-emergency-lights-blue-and-red/

It has happened to all of us at one point or another. We have been walking down the street or traveling along in a car or on a bus when suddenly, you see red blue and flashing lights behind you. You know immediately that it is some form of an emergency vehicle, whether it be a police car, an ambulance or first responder, or a fire truck. It does not really matter where you are in the world, blue and red flashing lights are pretty universal as the mark of an emergency vehicle, as well as the distinctive sirens. In the United Kingdom, police lights and sirens are affectionally referred to as ‘blues and twos’ – alluding to the blue flashing lights (which, of course, are now not always blue!) and the distinct two-tone siren (which again, is not always two-toned!).

If you have always wondered why this is the case, this is the article for you, as we explore the answer to the question ‘Why Are Emergency Lights Blue and Red?’  and much more!

There are several different purposes to the lights on an emergency vehicle. Their main objective is to provide a visual signal that the vehicle is there and to convey the urgency of the journey. For example, an ambulance may be heading to the scene of an accident or from an accident scene to a hospital. Its emergency lights will alert other drivers of its presence so that they can move out of the way and let it pass.

At other times, lights may be used to notify other drivers and road users that there is a problem in the area – perhaps, the emergency vehicle is parked near to the scene of an accident or another dangerous location. This will give the other drivers the chance to slow down, take extra precautions in the area or take a detour around it.

A third reason for a police car using flashing blue and red lights to signify that you have done something wrong – perhaps speeding, failing to obey a traffic signal or they suspect that you are driving under the influence of alcohol or illegal narcotics. At these times, seeing emergency lights in your rearview mirror will let you know that a law enforcement officer wants you to pull over and talk to you about what you are doing wrong.

In the early days of emergency vehicles, police cars in many US states simply had a single red light, that did not flash. It is thought that red was chosen because red is generally associated with ‘stop’ and other vital warnings in the United States. However, as time went on, more and more emergency vehicles decided to use flashing lights, and began to add in a second color: blue.

While red lights make most people stop, they can also lose visibility in a line of heavy traffic, as many tail and brake lights are red. By adding in blue lights, the vehicle immediately becomes more visible to other drivers. It is also thought that while red lights may be more apparent during the day and blue lights may be more visible at night. Using a combination of both flashing red and blue lights will help to alert drivers regardless of the time of day. Some experts also believe that using both red and blue lights alleviates problems associated with drivers who are color blind. People who have difficulty seeing red often have little or no trouble seeing the color blue. Likewise, drivers who can’t see blue can nonetheless see red. Using a combination of red and blue lights thus helps to alert all drivers, even those who suffer from color blindness.

How are police cars maintained?

Civilian vehicles are generally measured by mileage. Once they have done a certain number of miles, their value drops or they are required to have certain checks done. However, this is not the case with police cars. They are measured in hours. Law enforcement vehicles can spend a lot of time sitting and idling, which does not add to the mileage but does increase the wear and tear to the vehicle, so the meter on the dashboard records how many hours a police vehicle has been on. Police cars are not usually taken to a standard garage to be serviced and have any repairs done. They are generally done ‘in-house’ by specialist mechanics, in order to reduce the time that they are taken off the road and to make sure they are safe and completely roadworthy. No one wants a cop car to break down in the middle of pursuing a wanted criminal, after all! You can buy ex-police cars in auctions, and while they may be old in terms of hours, they are often very well maintained and can be bought for an excellent price. Many of them come with some great extras –  heavy-duty suspension and beefed-up internals and cooling systems, which often do not get used!

Pretty much all po­lice cars are based on standard production models of civilian vehicles. There are some rare cases where exceptions are made, where military vehicles are converted for use by the police. There are no manufacturers making cars solely for use as law enforcement vehicles. Instead, car manufacturers make special “interceptor” or “police” versions of specific models — usually large sedans. Also, police departments occasionally purchase civilian vehicles that fit their particular needs and customize them for a particular use.

The most common police vehicles in the United States:

• Ford Crown Victoria
• Chevrolet Caprice or Impala
• Dodge Charger

All of these models fit the typical profile of a police car: large sedans with plenty of room in the trunk for equipment, lots of space in the back seat for suspects and a relatively large engine.

The back of a police car is often made of hard plastic so that it can be cleaned up easily and quickly – not surprisingly, they get covered in bodily fluids of some description on a regular basis. They can also be quite cramped. This, to some extent, this is done to suppress people psychologically in the back seat, but it also makes it tougher to gain leverage or momentum if someone tries to launch an attack from behind.

The rear windows of the car nare reinforced with a wire mesh — although they are not usually bulletproof. While they are obviously strong, they can be kicked out by someone if they put enough force behind it. Needless to say, the rear doors of a police car cannot be unlocked from the inside!  In the trunk of a patrol car, officers can store any bulky equipment that they may need at a crime scene. This might include bulletproof vests or other body armor, a shotgun, first aid kit, a portable defibrillator, specialized tools, such as bolt cutters, or other gear specific to that officer’s training and assignment.

Hopefully, this article has given you a bit of an insight into police cars and how they are designed. Next time one goes past you with it’s ‘blues and twos’ going, you will have a better understanding of why, how, and what they are like inside – without having to get inside!