The dynamic behavior and ride quality of railway vehicles are influenced by track quality. Monitoring riding comfort and safety is a major task of the Austrian Federal Railway’s Infrastructure Division. The track testing and recording car EM 250 provides a proven measuring instrument for modern track maintenance. Equipped with an inertial measuring system and an optical track gauge measuring system, the track testing and recording car can measure the track alignment and rail profiles at speeds of up to 220 km/h. The measurements, taken every 25 cm, provide binary data files that can be processed offline. Track quality parameters are measured as functions of vehicle acceleration and are stored in a database from which they can be easily retrieved from any computer in the company. The Bureau for Applied Mechanics and Mathematics was commissioned by the Austrian Federal Railways to develop the SIMULAT program for analyzing rolling stock dynamics. In developing the model, special consideration was given to the exact mathematical description of all elements affecting vehicle dynamics. Using an optical measuring system, the track testing and recording car determines the rail cross section on the basis of readings at individual points. The simulation program links the curve with the track data, allowing the analysis of the impact of worn profiles on running stability. For the simulation, the line layout and the track geometry deviations excite the model of track and vehicle. In a followup phase, the vector of generalized degrees of freedom is evaluated, and the results are displayed with a visualization program. The simulation results were compared with data recorded during a test run and showed satisfactory correspondence.