The track support stiffness measurement and evaluation system for slab tracks proposed in this study enables the calculation of the load–displacement diagram at the various measurement positions. Therefore, it is possible to evaluate the track support stiffness directly on-site without evaluating the spring stiffness of the elastic material through sampling or in situ testing, also enabling the evaluation of the deterioration of the elastic material. In addition, the performance evaluation data for elastic materials obtained through field tests using measurement equipment and software to track support stiffness are integrated and managed on the administrator′s computer. Therefore, the replacement plan is established, and the maintenance history is managed by identifying the replacement time and location of elastic materials. It is possible to evaluate the performance and condition of the elastic material at various points during track inspection and the track support stiffness and durability of the elastic material (spring stiffness variation rate, replacement periods, among others) at the current operating condition.