At the beginning of the song, a "Kenworth pulling logs", driven by Rubber Duck, is the "front door" (the leader) of three semi-trailer trucks (tractor and semi-trailer) when he realizes they have a convoy. Following the Rubber Duck is an unnamed trucker in a "cab-over Pete with a reefer on" (a refrigerated trailer hauled by a Peterbilt truck configured with the cab over the engine), while Pig Pen brings up the rear (the "back door") in a "'Jimmy' haulin' hogs" (a truck powered by a two-stroke Detroit Diesel engine (A.K.A. Screamin' Jimmy) with a livestock semi-trailer loaded with live pigs).