Tracing rail transformation: the case of passenger services in Slovenia from 1975 to 2015

In the 1990s, Slovenia was part and neighbor of a series of disruptive events, undergoing a change from member state of a diverse socialist federation to a small, independent market economy country. These comprehensive changes were followed (or accompanied by) partially dramatic changes in the transport regime. In order to trace the change of the passenger railway service a method for the analysis and characterization of the timetable offer in public transport is developed and applied to ten timetable years between 1975 and 2015 on the main lines between Ljubljana, Maribor and Zagreb. This method is based on a cluster analysis of origin–destination relations with the three variables of daily direct connections, the number of trains with synchronized intervals as well as the overall regularity of travel times. In general, an overall increase of the quality of the rail service supply is shown, focusing on the decades from 1975 to the end of the 1990s. From 2000 to 2015 relatively little changes were identified. While a very dense offer was developed in regional traffic within the wider urban areas of Ljubljana, Celje and Maribor, the direct cross-border inter-city connections to/from Zagreb have been increasingly neglected. The example of the connection between Ljubljana and Maribor demonstrates the development towards a supply-oriented integral timetable until the 1990s. Thereafter, the timetable was thinned out and gradually developed with a demand-driven principle, where a higher train density was offered to Ljubljana in the morning and to Maribor in the afternoon.