This European Prestandard specifies the track alignment design parameters, the rules and the values that shall be used to determine the maximum operating speed for both new and existing lines. Alternatively, for a given specified speed, it defines the track alignment design parameters either for a new line or an upgraded line. The track alignment designer is free to specify the values most appropriate for the various parameters, when considering safety, geographical, engineering, historical and economic constraints. These values are defined in the contract document. However, the choice should be such that the selected values are no worse than the maximum (or minimum) limiting values for the safety-related parameters. Whenever necessary, the track alignment designer should take into account any specific requirements of the appropriate national standards. The designer should endeavour to use the recommended limiting values specified in this European Prestandard and avoid unnecessary use of the maximum (or minimum) limiting values. This European Prestandard applies to main lines with track gauges 1435 mm and wider with mixed or dedicated passenger traffic, running at operating speeds between 80 km/h and 300 km/h. Annex F (informative) describes the conversion rules which can be applied for tracks with gauges wider than 1435 mm. Annex G has a normative character and is applied for corresponding specific national conditions. However, the values and conditions stated for this speed range can also be applied to lines where operating speeds are less than 80 km/h, but in this case, more or less restrictive values may need to be used and should be defined in the contract.