Unfortunately, the resources were not available for this research to create a highly accurate friction model. However, the model presented is the same as the one commonly used for road vehicles, which has been known to produce very good results. Special concerns for roller coasters are not dealt with by this model, such as the forces on the different sets of wheels. Experiments would need to be performed, requiring access to a roller coaster car and track. Since these facilities were not available, a simplified model will be described as follows.
The model presented here provides the general framework of a friction model, accounting for an aerodynamic term, a force dependent term, and a force independent term. The specific values used in this model are implementation dependent, and may vary with each roller coaster. The model is intended to be complete enough, yet flexible enough, to allow a designer with a knowledge of the appropriate friction coefficients to be able to utilize them.
With the friction model expressed as equation 3.2, the force balance of equation
3.1 can be rewritten as follows.