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History of Road Work Signs

June 17, 2019

The paving of roads existed long before cars or the industrial revolution. In fact, the earliest roads as well as traffic signs began appearing in Ancient Rome. Connecting towns with roads for horseback and carts helped the development of commerce and travel. Here’s a look at how road work signs have evolved.

Early Traffic Signs

Once bicycles and automobiles became popular in the late 19th century, which sped up transporting goods and passengers, signs were posted by local officials to regulate traffic. The first standards for road signs were set in the early 1900s by the Congress of International Touring Organizations in Paris. When the American Automobile Association was launched in 1902, its mission was to place navigation signs on roads to help travelers avoid getting lost.

Rise of Warning Signs

By the 1920s when middle class Americans were first able to afford cars, standardization of signs began to develop among in different regions of the United States. Various sign shapes communicated specific messages such as white diamond signs with black lettering, which alerted drivers to proceed with caution. Rectangular shapes conveyed direction and regulations.

An early guide for sign standardization was called the Manual of Markers and Signs, published by the State of Minnesota in the early 1920s. More manuals came out that decade about standards and traffic control devices, published by the American Association of State Highway and Transportation Officials (AASHTO) and the National Conference on Street and Highway Safety (NCSHS). It was the AASHTO that recommended in 1924 all warning signs have yellow backgrounds with black lettering.

When MUTCD Took Over

The Manual on Uniform Traffic Control Devices (MUTCD) was first published in 1935 during the Great Depression. This manual introduced three traffic sign categories: regulatory, warning and guide signs. A revised manual in 1939 called for illuminated signs with white reflectors so that they would have greater visibility both day and night.

In 1954 a new edition of the MUTCD introduced the yellow triangle-shaped Yield sign with black letters. Symbols on signs began to proliferate following the manual’s 1961 edition, which called for larger signs. This edition also emphasized the development of construction warning signs, which at first could be black or yellow.

Construction Signs Shift to Orange

The first orange signs warning about construction and work zones started appearing on roads after the 1971 MUTCD edition. Symbols depicting workers and flaggers were introduced to construction signs following the 1978 manual. Since then orange has remained the standard color for road work signs, along with yellow caution signs. Retro-reflectivity became a requirement for all signs on all public roads by the U.S. Department of Transportation and Related Agencies Appropriation Act of 1992.

The Men at Work sign became very prominent starting in 1968 to the point that it inspired the name of a popular 80’s band from Australia that rose to worldwide fame.

But after Cynthia Good, CEO/Editor of woman’s magazine Pink in Atlanta, complained Men at Work signs excluded female outdoor professionals, city officials agreed to repaint all signs to say “Workers” or “Workers Ahead” in 2008. The Arizona Department of Transportation’s Manual of Approved Signs also no longer uses gender-specific road work signs. It turns out MUTCD has banned Men at Work signage nationally since 1988.


Contemporary road work continue to help save lives and influence drivers to slow down in work zones. Contact Zumar at our Arizona, Washington or California location to learn more about how a wide range of signs can benefit your community.

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