An experimental investigation of combination vehicle aerodynamics, pertinent to crosswind and truck-induced disturbances, was performed. This was accomplished via 1/10 scale model wind tunnel measurements performed on 6 trailers and 4 tow vehicles, and various combinations thereof. For some tests, a non-metric tractor trailer model was placed in the flow field near the combination vehicle model. A large data base of aerodynamic characteristics was generated comprising 6 force and moment coefficients as a function of crosswind angle. The effects of airspeed, articulation angle, trailer and tow vehicle shape, surface roughness, and truck proximity were quantified. Preliminary results suggested some design and development guidelines for manufacturers, and ranges of crosswind sensitivity for various vehicle shape features.