This Part of this European Standard specifies the requirements for the homologation of track geometry quality parameters as measured by various measuring devices. These measuring devices are described in Parts 2, 3, 4 of the standard. This European Standard applies to all track geometry parameters including track gauge, longitudinal level, alignment, cross level (cant / superelevation) and twist. It defines each parameter and specifies the requirements for measurement, the analysis methods and the presentation of results.