The dynamic analysis models of the vehicle-track coupling systems discussed in previous chapters all face the challenge of truncated boundary effects on the solutions. To address this issue, this chapter presents a finite element method in a moving frame of reference (FEMFR) for the dynamic analysis of the vehicle-track coupling systems. A three-layer continuous beam model is developed for the slab track, and the mass, damping, and stiffness matrices of the slab track element in a moving frame of reference are derived. The vehicle is modeled as a 26-degree-of-freedom (DOF) element. This approach effectively eliminates the influence of truncated boundaries on the computational results while improving both accuracy and efficiency. The main advantage of this method is that, unlike conventional finite element method (FEM), the moving vehicle always acts at a fixed point in the numerical model. This eliminates the need to track the contact point relative to individual elements. Furthermore, the vehicle remains within the computational domain throughout the simulation, and never runs out of the truncated model. As an application example, dynamic analysis of high-speed train and slab track coupling system is carried out.