The 1954 15-page supplement to the 1948 Manual on Uniform Traffic Control Devices (MUTCD) included 47 revisions and a brief description of each. The 1954 manual represented the shift from using mainly regulatory and warning signs on interstate highways to including guide signs. This manual also adopted the use of white letters on green background for Interstate highways.
The North American road sign colors normally have these meanings:
* green with white letters for informational signs, such as directions, distances, and places
* brown with white for signs to parks, historic sites, ski areas, forests, and campgrounds
* blue with white for rest areas, food, gasoline or petrol, and lodging
* white with red or black letters for regulatory signs, such as speed limits or parking
* yellow with black letters and symbols for warning signs, such as curves and school zones
* orange with black letters for temporary traffic control zones and detours