An FBI agent goes undercover in the California Highway Patrol as officer Frank "Ponch" Poncherello. Members of the CHP have been robbing cash delivery vehicles and his job is to uncover the perpetrators. At the CHP he is partnered with a 30-something rookie, Jon Baker. Baker is a former professional motorcycle rider with a list of ailments and personal problems who is lucky to be in the CHP. They are very different people and immediately clash.