The European Railway Traffic Management system (ERTMS) aims at replacing the different national train control and command systems in Europe and will serve to make rail transport safer. In order to provide insight into safety developments within the European railway system, the present study evaluates ERTMS at both national and international integral level. For this purpose, the international data from European ERTMS implementations is combined with national data obtained from interviews with Dutch ERTMS stakeholders and safety experts. Effects of deregulation, dynamic specifications, interoperability and time drain make that allowing an interoperable railway system by implementing ERTMS appears not to be self-explanatory. Also, without an overarching process, cross-discipline understanding and improved ascribing meaning to data, implementing ERTMS does not mean the railway system will become safer.