Cherry Truckers(1976)

On their way to a convention in San Francisco, a group of female truckers work their way in and out of most every motel bed they run across. They haul a pretty hefty sexual payload, and they like to turn themselves loose on any lucky hitchhiker they pass by. As these gorgeous ladies of trucking cross America, they find themselves being drawn slowly into a sensual and kinky game of cat-and-mouse that threatens to run them right off course if they don't watch out.