Orange is a highly visible color that stands out against most backgrounds. For this reason, it is commonly used for traffic signs, safety vests, and other objects that need to be easily seen. In the United States, orange is the standard color for signs and equipment used in construction and maintenance work zones on highways and roads. The use of orange helps drivers see and understand important information to navigate safely through work zones where road conditions may be changing.
History of Orange as a Safety Color
The use of orange as a safety color goes back to the 1930s when the American Railroad Association recommended it as the color for safety flags and signs on railways. In the 1950s, orange became the standard color for signs and barricades used by highway construction crews. The Federal Highway Administration mandated orange as the uniform color for work zone devices in the 1970s.
The visibility and meaning of orange has become ingrained over the last 80+ years of consistent use. Drivers instantly recognize orange as a signal to be cautious and aware of workers, changes in road conditions, detours, and more. The color also stands out in contrast to green highway signs used for directional information.
Advantages of Orange for Work Zone Safety
There are several key reasons why orange is an ideal color for construction signage:
High Visibility
Orange has a long wavelength, meaning it reflects light and contrasts with most backgrounds. This makes it quickly noticeable to drivers amongst other colors. Studies by the U.S. Department of Transportation found orange traffic signs to have the highest visibility level compared to other colors.
Color Contrast
Most roads, vegetation, buildings, and skies appear in cooler, green and blue based colors. Orange offers a strong visual contrast to these backgrounds. The warm tone allows orange signs to stand out and capture attention.
Available Light
Orange maintains reasonably high visibility in both full daylight and at night when illuminated. It outperforms darker colors that can blend into shadows and low light conditions. Fluorescent orange pigments boost nighttime visibility further.
Distance Visibility
The brightness and hue of orange enable it to be detected from a distance. Drivers can see and start reacting to orange signs well before reaching them, giving more time to process and respond.
Quick Recognition
Decades of consistent orange use for road signs and work zones means that orange has strong recognition value. The color is firmly fixed as signifying caution and the need for awareness. This primes drivers to pay closer attention when orange signs are present.
Federal Regulations for Work Zone Orange
To maintain safety and uniformity across states, the federal government regulates the specific hues and luminance levels that qualify as “work zone orange” for signs and equipment.
The Manual on Uniform Traffic Control Devices (MUTCD) issued by the Federal Highway Administration defines work zone orange as having a dominant wavelength between 595 and 605 nanometers and a luminance factor of at least 0.40.
Materials and coatings used for orange signs, cones, barriers, barrels, and more must meet these specifications to comply with national standards. Using dark, faded orange or colors outside the defined wavelength would make signs less visible and recognizable.
Exceptions to Orange as the Work Zone Color
While orange is the nearly universal color for U.S. work zone signs and hazards, there are a few exceptions:
– Red: Used for stop signs, yield signs, flares, barricade tape, and high hazard equipment like cranes.
– Yellow: Used for center line striping in work zones instead of white, which could blend with concrete barriers.
– Green: Used for directional, distance, and informational signs around work zones.
– Blue: Used for designated parking and disabled parking signs in work zones.
– White: Used for speed limit and exit signs around work zones.
So while orange dominates work zones, other colors serve specialized purposes, working in conjunction with orange signs.
Use of Orange for Work Zones Worldwide
The United States is not alone in adopting orange as the visual cue for road construction safety. Here are some examples of orange sign usage in other countries:
Canada
Orange is the standard color for temporary work zone signs, cones, barriers, and fencing. Permanent construction signs contain orange but in contrast with white and black lettering.
United Kingdom
The UK also uses orange as the primary color for temporary signs and barriers in construction zones. Additionally, workers wear high-visibility orange vests. Permanent construction signs have black lettering on an orange background.
Germany
Germany follows European norms EN 471 and EN 1150 for work zone safety colors. Orange is required for all temporary signage relating to roadworks. Orange jackets are mandatory for workers on motorways.
China
China’s standard GB3847 specifies a similar fluorescent orange shade for road construction signage as used in the US and Canada. Orange cones, barricades, and vests are ubiquitous at Chinese work zones.
Australia
In Australia and New Zealand, fluorescent orange is specified for work zone signs under standard AS1344. Orange high-visibility vests are also required for road workers.
So while some localized variations exist, orange has been globally adopted as the visual cue to warn drivers to slow down and be cautious around road construction projects.
Psychological Impact of Orange
Why has orange become so ubiquitous for work zone warnings rather than other colors? Research on color psychology helps explain the inherent ability of orange to grab attention and convey hazard warnings.
Key psychological associations people have with orange include:
– Energy – Orange conveys excitement, enthusiasm, and vibrancy
– Warning – Orange is strongly linked to communicating dangers and hazards
– Attention – Orange is impossible to ignore in the peripheral field of vision
– Youth – Orange evokes feelings of fun, creativity, and impulse
Orange is energetic enough to stand out but not so aggressive as to feel overly alarming. The balance of vibrance, warning, and urgency makes orange perfectly suited for getting drivers to pay attention and proceed cautiously.
Improving Work Zone Safety
While orange signs are the first line of warning about construction zones, additional measures can help improve driver awareness and reduce accidents in work zones:
– Fluorescent orange colors and reflective coatings improve sign visibility at night.
– Larger signs and lettering provide more advanced notice to drivers.
– Sequential messaging signs prepare drivers for changing conditions ahead.
– More signs placed at shorter intervals creates redundancy.
– Bright orange barrels and channelizers provide visual lane separation.
– Flashing arrow panels guide drivers safely through lane shifts.
– Automated flagger devices are an alternative to using workers for directing traffic.
– Rumble strips audibly alert drivers of a work zone ahead.
– Radar speed signs encourage drivers to slow down.
– Police enforcement can deter speeding in work zones.
Conclusion
Orange has proven itself as the universal color for warning drivers about construction, maintenance, and utility work zones on roadways. Its visibility against varied backgrounds, inherent attention-getting properties, and decades of established precedent solidify orange as the standard color for signs, barricades, barrels, and other devices used to guide motorists safely through work zones. Compliance with federal color and luminance requirements ensures driver recognition across all states. Orange works hand in hand with other colors and a range of traffic control measures to reduce risks for both drivers and workers in construction zones.