A garbage truck in 1986
A garbage truck was a type of truck that was used in late 20th century Earth that was operated by garbagemen, and designed to haul trash to a disposal site.
In 1986 San Francisco, these trucks were owned and operated by the San Francisco Department of Sanitation. (Star Trek IV: The Voyage Home)
At some point, garbage vehicles that were automated and capable of flight became common on Earth. In the alternate reality of the year 2259; Spock pursued Khan in San Francisco, and he tried to escape by jumping on top of flying garbage trucks called garbage barges. (Star Trek Into Darkness)