Safety or Marketing? Why we decorate our vehicles the way that we do

What Is Conspicuity? 

Conspicuity is the degree to which a specific object can be easily seen and recognized within its immediate visual context.1 There are two types: search conspicuity and attention conspicuity. The first refers to the ability of a person searching for an object to pick it out from the many objects in the field of vision. Attention conspicuity is the ability of an object to draw the attention of a person who isn't searching for an object.2

Three factors contribute to conspicuity: color, luminescence and form (shape). Little can be done to change a vehicle's shape (which for some is similar to non-emergency commercial vehicles), so improving conspicuity depends on the use of color and luminescence.

We've used color and luminescence, but are we using them correctly? Research has shown that contrasting blocks of color (the larger, the better) enhance conspicuity. Additionally, stripes should be avoided because they have a camouflaging effect.

The British Effort 

Much of the science regarding emergency vehicle conspicuity has come to us from the United Kingdom, where the Police Scientific Development Branch of the Home Office (analogous to the U. S. Department of Justice) conducted extensive research in an effort to develop the best possible marking scheme for law enforcement vehicles. That effort has now expanded to include vehicles of the U.K. fire and ambulance services.

Historically, British law enforcement agencies operated vehicles that were predominantly white, with a low-keyed color scheme. Known as the “jam sandwich,” this scheme offered little in the way of attention-getting effect. As in the U.S., many commercial vehicles in the U.K. sport graphics that use a “beltline” stripe, decreasing the likelihood that a public safety vehicle can be easily distinguished from them.

In October 1995, the Traffic National Motorway Policing sub-committee of the Association of Chief Police Officers of the U.K. determined that the police services needed a standard for marked patrol vehicles. Their determination was that police-patrol cars operating on a multilane or divided highway should be clearly recognizable and should have day and night visibility of 500 meters (about 1,650 feet). They also determined that this minimum distance should apply during such mildly inclement weather as rain or mist, although not necessarily in heavy rain or fog. They defined minimum illumination at night to be “that which is provided by an approaching vehicle with headlights set at the normal dipped position” but didn't include roof lighting on operating police vehicles as part of the definition.1

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London Ambulance Service completed the transition to the Battenburg livery specification, a highly visible marking scheme.

The program's objectives were to develop a scheme that would:

The result of this study was the Battenburg livery specification, a guideline for a highly visible marking scheme for police vehicles. Since its release, police service use has been steadily increasing.

By 2001, 46% of police forces had applied Battenburg to at least three-quarters of their patrol vehicles. A survey in 2003 shows this number to have increased to 76% and suggested this figure would likely climb to at least 85% by the end of 2004.1 The ambulance and fire services soon followed suit, and the visibility difference is significant.

The vehicle conspicuity effort has spread throughout the European Union (EU), where the international cooperative governance body has legislated EU standard ECE104, which requires high-conspicuity markings for all emergency vehicles. The London Ambulance Service, the largest ambulance service in the world, has recently completed the transition to its own Battenburg livery.3 An excellent visualization of the impact of high-conspicuity retro-reflective markings, day and night, can be seen on the Web site for Reflexite Europe, a maker of reflective vehicle and other marking products. (Editor's note: Read about a U.S. organization that uses Reflexite products in “Baldwin EMS” on p. 54.)

U.S. Models 

American emergency vehicle markings are, in large part, a matter of local or corporate discretion. Complex logos, attractive swirls, and multicolor schemes reflect the individual agency's identity. Some agencies rely on tradition, even when the selected color scheme will clearly detract from conspicuity.

The government attempted to standardize ambulance markings in the late 1960s and early 1970s. The triple K ambulance purchasing specification, KKK-A-1922-A, was published and became a requirement for ambulances purchased by agencies receiving federal grant dollars.4

This standard prescribed an essentially white color scheme, with a 12” belt-line stripe in “Omaha orange,” the new “Star of Life” graphic, and the word “AMBULANCE” in reverse lettering on the front. Although it has been documented that the triple K color scheme wasn't based on research or references, many states incorporated those specifications in their state EMS rules.5

The triple K color scheme wasn't attractive; it made ambulances look too familiar—like plumber's vans, delivery trucks or telephone company vehicles—and didn't allow integration of a unique organizational identity. Vigorous arguments occurred at the state level over whether it was acceptable to use “FIRE-MEDIC” in reverse lettering instead of reversed “AMBULANCE” on licensed ambulances operated by fire service agencies. Soon, many states backed away from mandating triple K markings.6 Other paint schemes are now frequently seen on non-federal ambulances, although orange and white is still installed on federal vehicles throughout the country.

In an article entitled “Inattentional Blindness and Conspicuity,” the author discusses the concept of “expectation” as a subconscious mechanism that filters the bombardment of sensory inputs and selects a small percentage of them for full perception and conscious attention.7 The author discusses the role of expectation on the ability of a person to sort out what's relevant and what's not from the huge variety of visual inputs—for example, the ability of an EMT or a paramedic to generally ignore a busy dispatch radio but immediately notice when their unit number is called.

Does the vast variety of ambulance-marking schemes in the community detract from the ability of drivers and pedestrians to recognize an ambulance, focus on it as something different from an ordinary light truck and react appropriately to it? This question was clearly on the mind of the U.K. researchers who made identification of police cars as police vehicles the criteria of their desired marking scheme.

In the past decade, our industry has moved away from a standardized look for vehicles, and the trend is for even greater use of EMS vehicles as corporate billboards. Logos that aren't quickly associated with emergency services—such as soft, corporate color schemes and attractive, flowing graphics—may contribute to the unified corporate image desired by the marketing and public relations staff, but it's at the expense of the safety of responders, patients and community at large.

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Research shows that deliberate use of color and luminosity—such as the chevrons on the back of this vehicle—enhance conspicuity.

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The generally two-toned scheme found in many communities is believed to be even less visible than single-colored vehicles.8 One researcher recommends that all emergency vehicles be outlined with retro-reflective material, stating that incomplete coverage is discouraged because it may contribute to the “camouflage effect.”8, 9

Does Conspicuity Play a Role in EMS Safety? 

Although research addresses visibility, conspicuity and safety in allied disciplines (most notably highway construction and repair), and its benefits all appear to be intuitive, we've found no studies that specifically addressed vehicle conspicuity and safety in the EMS environment.

The U. S. Fire Administration (USFA) is conducting a study of emergency vehicle visibility and conspicuity in cooperation with the International Fire Service Training Association, the National Institute of Justice, and other organizations.10 We believe the EMS industry, through its professional associations, should become actively engaged in this effort.

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The exterior design shown on these vehicles consolidates the factors of conspicuity, using prismatic decaling material and patterns with large blocks of contrasting colors.

In the meantime, we encourage EMS agencies to adopt the best practices used in related industries and to take steps to improve the safety of our personnel and vehicles by improving conspicuity. Some of these best practices are described in the USFA publication “Emergency Vehicle Safety Initiative,” which can be downloaded at www.usfa.dhs.gov/downloads/pdf/publications/fa-272.pdf.

Emerging Trends 

Awareness of the importance of vehicle conspicuity continues to gain momentum across the country. Progressive emergency response agencies are taking steps to incorporate contrasting color, luminescence and safety-oriented designs in their vehicle specifications.

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Montgomery County (Md.) Fire and Rescue Service recently adopted a policy and procedure document addressing vehicle markings and safety graphics for county-owned fire and rescue vehicles. This document prescribes substantial use of retro-reflective materials on emergency response vehicles, including large chevrons of 6″ alternating red and white materials.11 In addition to the usual side and rear markings, the standard prescribes reflective material for the front bumper and inside of each cab door.

The Wake County (N.C.) Department of Public Safety's EMS Division has improved the conspicuity of its emergency vehicles in two phases. The first phase, adopted in 1999, was a new color scheme that abandoned the service's historical non-reflective forest green and white in favor of a reflective blue-and-white design. In 2005, large, high-visibility chevrons of blue and luminescent yellow were added to the rear of ambulances and support vehicles (see photos, p. 46). Reflective panels were also added to the inside of the rear doors of all ambulances. Further efforts to enhance conspicuity, including the adoption of Battenburg-style markings, are under consideration.

LifeNet EMS of Texarkana, Texas, recently changed its color scheme to improve visibility and conspicuity, demonstrating their commitment to vehicle safety. The service moved away from its established teal blue and gray to white vehicles with fully reflective markings, special reflective trim and large, rear chevrons.

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LifeNet EMS of Texarkana moved to white vehicles with fully reflective markings (left)— away from its previous color scheme of teal and gray (right).

Conclusion 

If we truly believe people are our most important asset, we must make every effort to safeguard them. We must provide our workforce with the tools and equipment necessary for them to do their jobs safely. As improvements in automotive sound and insulation technology limit the effectiveness of sirens as emergency-warning devices, and as public perception becomes dulled by the proliferation of flashing-light patterns on everything from construction vehicles to ice cream vendors, we must pay closer attention to the ability of our vehicle graphics to promote safety. We need to do more to break through the inattention of drivers whose focus is everywhere but on other vehicles sharing the road with them.

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This vehicle uses retro-reflective materials for high visibility during the day and at night.

Additional research is needed in this area but, in the meantime, conspicuity—and thus, safety—may be enhanced by adding large blocks of contrasting, reflective, luminescent colors and large, rear chevron patterns to your fleet of emergency vehicles. To compare your agency's vehicle conspicuity to the Crestline High Visibility Emergency Vehicle package (shown on p. 50), go to www.crestlinecoach.com/evcon.

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This vehicle from Austin-Travis County also shows the trend toward rear chevrons for safety.