Where does the US DOT or MDDOT number go on the vehicle?
Either the US DOT number or the MDDOT number must be displayed as specified in the Federal Motor Carrier Safety Regulations part 390.21(c): (1) appear on both sides of the self-propelled commercial motor vehicle (CMV); (2) be in letters that contrast sharply in color with the background on which the letters are placed; (3) be readily legible, during daylight hours, from a distance of 50 feet while the CMV is stationary (lettering should be a minimum of 2 inches to meet this requirement); and (4) be kept and maintained in a manner that retains the legibility.
