A tourist trolley, also called a road trolley, is a rubber-tired bus (usually diesel fueled, sometimes compressed natural gas), which is made to resemble an old-style streetcar or tram. The name refers to the American English usage of the word trolley to mean an electric streetcar. As these vehicles are not actually trolleys, and to avoid confusion with trolley buses, the American Public Transportation Association (APTA) refers to them as "trolley-replica buses".