In the paper data formats and tools supporting syntactic and semantic validation of data sets in the railway domain are presented. A description of the XML format with its defining grammar as base for languages of railway data and an explanation of the Schematron language for semantic rule modelling
will be given. Building upon that description a process for the validation of railway data is introduced, which was designed with the aim of increasing the data quality in planning, simulation and operation applications. The process of rule definition begins with a rule formulated in a natural language. It is proposed, to include formal rules in the language’s grammar if possible. All other rules should be written in Schematron language enabling a cascade of transformation steps to produce a human readable output. This process is demonstrated with the example of signalling systems in the PlanPro data format developed by the German railway infrastructure manager Deutsche Bahn Netz AG. In a case study it is shown which time saving effects can be achieved in the checking process of a signalling planning in a medium size station.