Work conducted within REORIENT, a Sixth Framework project for the European Commission (EC), is described. One objective of REORIENT was to explain the status of transformation of the European railway sector into a functionally integrated, interoperable system. The status of interoperability within and between 11 countries in a corridor stretching from Greece to the Nordic countries was assessed, and conditions in the countries that appear to be barriers to achieving interoperability were identified. Barriers were defined as shortcomings in conditions that would facilitate the implementation of requirements presumed by the EC to lead to seamless international freight transport (implementation conditions). The primary data source for the analysis was a set of interviews with the major actors and stakeholders associated with each country's rail freight system. The qualitative information from the interviews was translated into numeric scores, which were subjected to statistical analysis. The objective of the statistical analysis was to provide an assessment of the relationships between the requirements and the implementation conditions. The statistical analysis involved both the identification of relevant relationships and an assessment of the strength of these relationships. A Barrier Significance Score (BSS) was computed for each country and for each implementation condition. These scores were used to assess the relative importance of barriers across the studied countries and to identify the most critical barriers to be removed in order to improve interoperability. Very large differences in BSSs were found between countries. In general, there are fewer barriers in Nordic countries and more barriers in the south.