The paper describes analytical work aimed at providing understanding of and alleviating problems associated with the running of heavy rail vehicle traffic on curved track. Such problems include wheel and rail wear, track structure fatigue or damage, and reduction in track carrying capacity due to high maintenance. An analysis is provided concerning the steady state behaviour of rail vehicles on curved track, subject to operational factors such as operating speed, traction or braking, and coupler forces. A mathematical model is used which considers non-linear rolling friction characteristics on the wheel treads and on the flanges. The bogie model can represent different design configurations and takes account of detailed features present in actual bogies. Model results are compared to field test results obtained on a six-axle freight locomotive. The model is inexpensive to run and can be used in a variety of applications such as the design of vehicles, the comparison of different designs, the investigation of operational problems and the design of field test procedures. The model can also be used to support research in the areas of wheel-rail wear mechanisms, and fuel consumption due to curve rolling resistance.