How Wide Is a Semitruck?

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The width of a semitruck or semitrailer varies depending on the cargo and manufacturer. Department of Transportation regulations limit the width to 102 inches — except in Hawaii, where the maximum width is 108 inches. U.S. federal regulations correspond to international standards, which limit width to 2.6 meters.

The width regulations exclude mirrors and certain safety equipment. The regulations do not apply to all commercial vehicles, such as farm equipment, military vehicles and road construction vehicles. There is no federal length limit for semitrucks, but there is a minimum length limit such that no state may impose a limit lower than the federal minimum. As of 2014, that limit is 48 feet, and some states have a limit as long as 59 feet.