At present, different cargo types with varied dimensions exceeding vehicles maximum permissible dimensions are transported by road transport, and thus, their operation can significantly influence road traffic safety across Europe. Slovakia applies Government Regulation No. 349/2009, which also regulates a maximum permissible dimensions of vehicle categories. This paper deals with cargo the whose dimensions of which exceed the dimensions of the semi-trailer. The paper describes circle of vehicle maneuverability, which states that each vehicle must be able to maneuver in the inner circle as the minimum criterion and must be capable of maneuvering in the outer circle as the maximum criterion. The paper also describes the influence of the truck's fifth wheel axle position on the articulated vehicle total length, which affects the maximum cargo permissible length in the rearward direction. The next part of the paper is about impact of the fifth wheel position to the minimum width of the road lane in depending on wheelbases size of tractor. Within this research study, for the purpose of verifying the theoretical calculations, series of measurements confirming these calculations were performed.