A generic lateral plane rail passenger truck model with truck frame lateral and yaw motion and wheelset lateral and yaw motion degrees of freedom is developed. The maximum number of independent stiffness elements interconnecting the two wheelsets and the truck frame is identified and the critical speed versus curving performance envelope is obtained for a configuration derived from the general formulation and compared with conventional and radial truck configurations.

The number of independent elements in the stiffness matrices of asymmetric and symmetric rail vehicles represented by a carbody and two trucks are determined and the influence of direct carbody-wheelset interconnections on vehicle stability and curving performance is illustrated.