The Evolution of Emergency Lights and Sirens

From spare taillights and brass bells to multi-color LEDs and smart sirens

Watching a fire engine blazing down the highway with full lights and sirens is quite a rush, almost awe-inspiring. The wail of an ambulance expresses the urgency of a perilous situation. A police vehicle firing up its complement of lights, especially when viewed from a rearview mirror, can tie your stomach in knots. These warning devices send a message that elicit both an emotional and physical reaction. From their humble beginnings in the late 18th century to the connected, autonomous technologies of today, the history of emergency warning devices is fascinating from both a technical and cultural perspective.

On Foot and By Hoof

Before fire trucks, horses galloped on cobbled streets pulling water pumps on carts behind them. The sirens of the day were the trusty Dalmatians that warned others of the emergency. The famous and distinctive dogs have notoriously loud barks, so they could run out into the street ahead of the fire crew to clear traffic. The alarm was a brass bell mounted on the water pump assembly that echoed the canine’s report.

Police officers also rode horses on occasion, patrolling city streets and keeping watch. They would hitch up a “paddy wagon” if things got especially dicey. More often than not, officers walked their assigned beats for the duration of their shifts. If they spotted trouble, they ran towards it puffing on a whistle to alert by-standers of the danger and to give way.

As motorized transportation grew and evolved, public safety vehicles and emergency response changed dramatically. Then someone got the idea of using specialized lights.

Pedal to the Metal

In the early days, emergency lights were single beacons, usually made from spare taillights. This kept costs down, but options were limited and they did little to convey a sense urgency. As automotive technology continued to advance and roadways started clogging up, lightbars were needed to increase visibility. Lightbars introduced motion to warning lights with rotating lamps. Reflective materials also increased light output. The lighting and warning equipment also took on an aerodynamic shape to improve fuel economy. Form and function steadily improved.

But why are some warning lights blue and who decided what color combinations to use? There are a variety of opinions and theories about when, why and how certain colors became associated with emergency vehicles. As discussed earlier, police cars used to only have red lights for practical reasons. Psychologically, people connect the color red with danger and, in more modern times, are conditioned to stop at a red light. Blue was added in the 1960s, which was a popular emergency color in Europe. Conventional wisdom dictates that the red and blue combination was meant to address color blindness, so everyone could see at least one of the two colors in day and at night. Today, the options and combinations are endless with red, blue, white, amber and occasionally green colors.

Mechanical and electrical sirens have come a long way as well. Invented in the 1700s and originally intended as a musical instrument, the early siren was cumbersome and relied on compressed air to operate. Consequently, the devices were stationery and impractical for use on automobiles. As the need arose for a mobile, hands-free audible warning capability, whistles were attached to exhaust pipes. The whistle was a short-lived solution as the shrill sound was overwhelmingly unpleasant.

Over time, mechanical sirens became smaller and more efficient. In the 1960s electrically powered sirens hit the scene. They were louder and more effective. The new sirens could be customized, giving police, firetrucks and ambulances distinctive audible signatures. Drivers and pedestrians could now hear which kind of vehicle was approaching and react accordingly.

Today and Tomorrow

The evolution of emergency lights and sirens is seemingly random with trial-and-error leading to what we have today. Times have changed with standardization and regulation guiding current and future development. All products must meet stringent federal standards like SAE J845 for optical warning devices and J595 for directional flashing optics. J1849 regulates lighting output, KKK-A-1822 outlines further specifications for ambulances and even states like California issue additional requirements such as Title 13 Article 22 for warning lamps.

It sounds overwhelming but Code 3 has teams of professionals to figure all of that out for you. They ensure all lights and sirens exceed national and international standards. From lightbars to beacons, sirens to backup alarms, quality and visibility are assured.

Considering how much has changed in just the past 30 years, it is safe to say the next 30 will revolutionize public safety. Advancements in sensor technology, smart roadways and vehicle connectivity are already being integrated into warning devices. Code 3 has grown and adapted to these trends over the years. They are now on the cutting edge of innovation, developing emergency systems for the next generation.