Abstract
During the railway track life, its operational quality is represented by the key information on the extent and method of its degradation, applying indicators which were appropriately selected, surveyed and evaluated within the diagnostic activities. The paper describes methods and procedures of experimental verification, i. e. obtaining and evaluating operational quality indicators, representing design parameters and determining its quality. Determining the dependence of the values of different quality indicators on time or place of measurement allows to construct models of structure behaviour over its lifetime and to predict the time and place when and where the permissible boundary values of the qualitative indicators can occur. The paper presents the models prepared for monitored experimental sections in the Slovak Railways (ŽSR) network.