A highway patrolman was a police officer whose regular duty was to patrol up and down a highway. In 1930, a highway patrolman in Lee's Summit had apparently stopped a number of cars without proper license tags. According to a statement he made to a New York City newspaper, the most common excuse for motorists driving with out-of-date tags was because they expected to be drafted and didn't want to waste money on licensing a car they wouldn't be able to use. (TOS: "The City on the Edge of Forever" )