When I do this song, semi-comically, I point out the problems brought about by privatisation of the railways: the fact that no bill of lading, or other documentation is required to identify the cargo, the word of the driver, whose interest is in avoiding toills, is accepted by tollbooth man and tollbooth man can't tell difference between cattle truck and bulk ore wagon...
Still a damn good song tho'

RtS
(I may be right....)