This European Standard defines the minimum requirements for the quality levels of track geometry, and specifies the safety related limits for each parameter as defined in EN 13848-1. This standard covers the following topics: - description of quality levels; - relative importance of parameters; - immediate action limit; - considerations on other quality levels. This European Standard applies to high-speed and conventional plain line of 1 435 mm and wider gauge railways provided that the vehicles operated on those lines comply with EN 14363 and other vehicle safety standards. For lines covered by the high speed infrastructure TSI, the requirements stated in the HS INS TSI prevail. Any track geometry parameter not covered by the HS INS TSI needs to be compliant with this European Standard.