Abstract
This report contains an account of wind tunnel tests carried out in the transport engineering division of TRRL to illustrate the more important aerodynamic features of heavy goods vehicles. Basic parameters such as trailer height, tractor-trailer gap size and leading edge radii are discussed, together with the differences between several popular vehicle configurations. A brief mention is made of full scale vehicle tests being undertaken at TRRL, together with wind tunnel correlation work. The report concludes with an outline of proposals for the next round of wind tunnel tests, concentrating on drag reduction techniques. (Author/publisher)