A Review on Emergency Vehicle Warning Systems

A Review on Emergency Vehicle Warning Systems

Emergency response vehicles use siren and lights while on the road to prevent a collision. Markings, as well as visual and audible warning devices, are crucial to reduce the risk of accidents and negotiate the flow of traffic effectively. It’s important to understand the features of these warning systems to implement guidelines for emergency situations properly.

Visual Warning Devices

Studies show that more than 90% of motor vehicle drivers’ sensory input is obtained through visual cues. Therefore, visual warning systems like tow truck LED strobe light bars play a critical role in alerting drivers of an approaching emergency vehicle. Driver alertness, conspicuity, visibility, and field dependence are also considered when determining whether an object is perceived appropriately.

Flashing lights have been proven to be the most effective solution to gaining attention. While this is generally accepted, some authorities believe that all lights from the same side should flash in unison to outline the shape of the vehicle. The established colors for warning lights are white, green, yellow, and red.

Audible Signals

Field studies reveal that reaction time to visual warnings improve significantly when accommodated with loud auditory signals. Emergency vehicles have always used sirens and other audible warnings. In fact, most state laws require these devices on their runs. These should include a wide frequency and sufficient power to overcome the noise in a high-traffic road.


Some emergency vehicles — ambulances, in particular — have the same configuration as commercial cars. This is why markings and colors are important, as they allow motorists to differentiate emergency cars easily from other vehicles. In a 1984 study, it was reported that collision rates for fire trucks using lime yellow color scheme were significantly lower than those who use traditional red.

These facts only prove that warning devices must be carefully reviewed down to the smallest details. When properly implemented, they can reduce traffic accidents and save lives.