low poly big truck, Everyone who works in transport every day comes across the colloquial description of a road set (tractor + semi-trailer) as a TIR. This term has become so deeply entrenched in everyday speech that it will probably no longer be treated as erroneous by linguists at any moment. It is worth remembering, however, that the word TIR means something completely different. It is an abbreviation derived from the name of the customs convention, from the French Transport International Routier.