This European Standard specifies the requirements for the homologation of track geometry quality parameters as measured by various measuring devices fitted on track recording vehicles. These measuring devices are described in Part 2 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. Parts 3 and 4 give a description of measuring devices complying partially with this Part 1 according to the specificities of respectively track construction and maintenance machines, and manual and lightweight devices.