This two-part article reports on the renewal and adaptation of the fixed railway track in the heavily frequented underground train station at Zurich Airport. The fixed track built in 1980 had reached the service duration predicted by the system provider and was showing damage. In order for the platforms to meet the requirements for people with disabilities, the track geometry had to be adapted in sections by lowering. For this reason, a simple exchange of the sleeper blocks was not possible and a special solution was required. With the use of the Ultra-High-Performance Fiber Reinforced Cement-bound composite building material UHPFRC, a sustainable and economical solution was found for a project in which a traditional solution would have been time-consuming and costly. In addition, it was found within the scope of this project that the use of UHPFRC with significantly improved mechanical properties increases the service duration of the fixed railway track. With the use of UHPFRC, the service duration of the fixed railway track becomes equal to the one of the whole train station, which further improves economic efficiency.