Construction and work-zone signs in the United States are orange. The color alerts drivers that temporary road conditions, workers, lane shifts, or equipment may be ahead.
Orange is part of the United States’ standardized traffic-sign color system, whose designs are set out in the Manual on Uniform Traffic Control Devices. Temporary warning signs may announce road work, a closed lane, a detour, a flagger, or workers operating near moving traffic. Orange helps distinguish these temporary conditions from permanent warnings, which are commonly yellow, and from regulatory instructions, which are often white, black, or red.
A frequent mistake is assuming every construction sign is yellow because both colors warn drivers. In the US, yellow is the general warning color, while orange identifies temporary traffic-control situations associated with construction, maintenance, or utility work. Work-zone signs may be mounted on portable stands, attached to barricades, or displayed alongside cones and channelizing devices.