The CROSSMOBY project addresses the challenge of improving capacity in sustainable mobility planning and providing cross-border public transport links based on a strong institutional cooperation approach to achieve concrete results for citizens in the Programme area, including in terms of reducing transport emissions. The main objective of the project is to set up new sustainable cross-border transport services and to improve mobility planning within the whole area. The expected substantial changes will take the form of testing new rail passenger services and a new approach to mobility planning, based on the existing PUMS methodology applied to a limited number of pilot projects. The main outputs of the project are the reactivation of cross-border rail passenger services and a cross-border strategic action plan on sustainable mobility, which contribute to making CROSSMOBY an original and new project, since there have never been previous projects in the Italy-Slovenia cooperation programmes that have led to similar results. In addition, in order to address the lack of sustainable mobility options and to improve accessibility across borders, cross-border cooperation proves to be necessary where the competent authorities and other organisations in Italy and Slovenia are able to develop services in a coordinated manner.