The transition effect between different track-foundation systems is examined from the point of view of energy that is produced during the passage of load. Analytical solution is given. A model of beam on elastic foundation with damping is used as the base model. It is developed into a model composed of two parts that represent the track-subgrade system with an abrupt change in mechanical parameters: bending stiffness, foundation stiffness, damping, and mass. Several calculations are carried out including examples of comparative calculations with the Finite Difference Model and the Finite Element Model. Transient rail deflections and energy are determined, which may serve to estimate the rate of track-subgrade deterioration.