The term 'highway truck' can be summarized as a large vehicle used to transport goods on highways. The term is often used interchangeably with the term 'SEMI, ' which is a four-letter word that refers to a tractor-trailer combination. SEMI trucks are typically used for long-distance hauling, and they are designed to carry large loads of cargo. They are also equipped with special features such as air brakes, air suspension, and other safety features.