Projects relating to public cross-border passenger transport infrastructures and their modes of operation were a major focus, highlighting the significant role played by institutional players at all stages - the planning, construction and operation of transport systems. A further aim was to pinpoint the interactions between the projects under investigation and other projects or modes of transport, particularly road transport, and the modalities of their integration in overall transport policy in the region concerned, wherever such a policy exists.

Indeed, there is no such thing as a public transport policy on the one hand, and a private one on the other. Instead, there exists an overall policy in which various projects and modes of transport interconnect and interact with each other. Several projects centred on five Swiss border regions were examined in this perspective. They are characterised by a given spatial organisation (urban or rural context, high or low density of population and jobs, etc.), a set of problems relative to transport (link-up to a major international railroad main line, volume and nature of transboundary traffic, etc.) and different habits of co-operation (length and intensity of transboundary relations).