This paper proposed a unified model including yaw and roll dynamics for any axle or articulation configuration of buses by using a reconfigurable approach. First, all the possible existing configurations of buses are introduced, including the axle/articulation configuration, powertrain configuration, and active chassis control configuration. Consequently, the research is motivated by a key question: how can we develop a unified model that is inclusive and configurable to all of the above bus configurations? To develop the model, three layers of the modeling process are presented step by step. The magic formula and vertical load transfer are discussed to formulate the tyre model. It is noted that the case of the articulated bus is presented in an independent section but how it is included and unified in a general form is also explained. Finally, a modeling validation of axle or articulation configuration cases is performed and the comparative results to high-fidelity models show the feasibility, efficiency, and convenience of the reconfigurable approach. As the crucial feature, the resulting model can be potentially applied to model-based controller design in any buses without reformulating the model. This will greatly benefit the vehicle dynamics control and also future autonomous buses. Although the focus of this paper is buses, the proposed approach actually covers any multi-axle/articulated vehicles, like trucks, tractor-trailers.