The main objectives of the tram track design process are the rational use of urban traffic areas, while ensuring a safe and comfortable ride and long exploitation life. Generally, the guidelines for the design and maintenance of tram tracks in Zagreb, as a special group of track structures, have been developed based on engineering practices and experiences gained in the design and maintenance of railway systems. According to these guidelines, an important parameter in determining the needs for rehabilitation of tram tracks is the track gauge. The paper describes the examination of the impact of traffic volume, horizontal geometry design and incorporated elements of track superstructure on the increase in gauge divergence as decisive factor for the track reconstruction. The study is based on ten–year follow–up of changes of the tram tracks gauge. By classification and analysis of data collected by gauge measuring at more than 7 km of Zagreb tram tracks the impact of the route design and traffic volume on the process of track degradation is defined.

tram track, gauge measurement, horizontal geometry, superstructure, traffic volume