Why Red Is the Worst Color for Your Ambulance

Red is historically the color of choice for U.S. fire trucks and many ambulances—so much so that there’s even a popular color known as “fire engine red.” Yet red is arguably the worst choice when it comes to making emergency vehicles visible to passing motorists because “the human eye is red-blind at night,” says Stephen Solomon, OD, licensed optometrist and veteran volunteer firefighter.

Adding black chevrons and trim to the red doesn’t help the situation. “In fact, you cannot camouflage a vehicle better than to paint it red and black,” says Solomon, an expert in emergency vehicle visibility. “Red and black is completely absorbed into the background due to the way people see it, so you’ve made the vehicle practically invisible.”

In contrast, vehicles that are painted lime-yellow are optimally visible to motorists in all lighting conditions. This is because “the human eye is exquisitely sensitive to seeing that color, day and night,” says Solomon. “It is the part of the color range that is the brightest and the best attention-getter all around. So if you want your ambulances to be seen, lime-yellow is what they should be wearing.”

Backed by Science

According to Solomon, the debate over lime-yellow versus red emergency vehicles and their vulnerability to being hit by passing motorists was resolved decades ago. A 1984 study across nine fire departments in five cities showed average accident rates of 15.3/100,000 runs for lime-yellow fire apparatus, versus 31.9/100,000 runs for apparatus painted red. “In other words, red fire trucks are twice as likely to be hit as the lime-yellow ones are,” he says.

Solomon followed up on this research in 1995 with a paper entitled “Influence of Color in Fire Vehicle Accidents,” which he cowrote with systems safety engineer James G. King and published in the Journal of Safety Research. Their research expanded beyond the 1984 study to include total moving multivehicle accidents including fire pumpers that were either red or lime-yellow (both with white upper cabs) and equipped with emergency lights and sirens. The results were conclusive: “The superior visibility of lime-yellow color yields an earlier awareness of the fire pumper’s presence by the civilian driver and results in a lower accident rate.”

In 2009 FEMA’s “Emergency Vehicle Visibility and Conspicuity Study” came to the same conclusion. “Fluorescent colors (especially fluorescent yellow-green and orange) offer higher visibility during daylight hours,” said the FEMA report.

Life EMS Ambulance in Grand Rapids, Mich., uses a mix of green-yellow checkerboarding and white uppers on its ambulances to maximize visibility.

“Initially we started with the color green for branding, with no science behind it,” says President Mark Meijer. “We now use the checkerboarding and rear yellow-green chevrons to catch drivers’ attention, and it works. Although we don’t have firm accident statistics at hand, the public regularly tells us that our ambulances are more visible to them than other emergency vehicles.”

Retroreflective Surfaces Also Help

In its 2009 report FEMA emphasized the importance of retroreflective materials on emergency vehicles to boost visibility, in addition to visible color schemes and flashing emergency lights.

“Retroreflective materials are defined as those that (re)direct incoming light back to the viewer, such as the driver of a vehicle approaching a roadside incident scene,” the FEMA report explained. These can be used to outline vehicles using stripes and other shapes, letters, and logos, all of which allow motorists to figure out what type of vehicles are either approaching them or parked on the roadside. Retroreflective material is functional during the hours of darkness.”

Like lime-yellow body paint, “The increased use of retroreflective materials holds great promise for enhancing the conspicuity of emergency vehicles,” the FEMA report concluded. Better yet, “Using high-efficiency retroreflective material can improve conspicuity while reducing the amount of vehicle surface area requiring treatment.” To deliver maximum vehicle visibility, FEMA recommends outlining vehicle boundaries with “contour markings” using retroreflective material and concentrating retroreflective materials lower on emergency vehicles “to optimize interaction with approaching vehicles’ headlamps.”

“I am a very powerful supporter of retroreflective material because it is so brilliant at night,” agrees Solomon. “The best chevron combination is fluorescent lime-green/yellow alternating with red.” Adds Meijer, “It helps to ensure that our ambulances can be seen at night, even if they don’t have their emergency lights on.”

Why Does Red Persist?

Given that decades of research have proven the superiority of lime-green over red in making emergency vehicles more visible to passing motorists—thus reducing the number of accidents and resulting first responder/public injuries and fatalities—one has to wonder why anyone uses red anymore.

It’s a question Solomon has asked time and again, and for which he has yet to receive a compelling answer. Based on what people in emergency response have told him, red persists solely due to tradition and the fact that those in charge want their vehicles to be red, no matter what the science says.

“People use red on fire trucks and ambulances like they use wallpaper in their dining room,” Solomon says. “It’s a matter of being pretty,” rather than the safety of first responders and drivers approaching their vehicles. Until those in charge pay attention to the science, the poor visibility associated with red emergency vehicles and the unnecessarily higher cost in human injuries, lives, and damage to expensive equipment due to collisions may unfortunately continue.

James Careless is a freelance writer and frequent contributor to EMS World.