Measuring territorial cohesion impacts of High-Speed Rail at different planning levels

The conflict of efficiency vs. cohesion objectives is of particular interest in the transport planning field. If the only objective was the maximization of economic growth, the 'most efficient' policy would attempt to concentrate the economic activity in several strong regional centres and interconnect them with a high quality transport network, such as High-Speed Rail (HSR). However, this policy would have a negative impact on territorial cohesion, as it would lead to more polarized spatial development patterns. Aware of these polarisation risks of HSR, transport policy documents at different administrative levels -from the local to the European scale- are increasingly demanding the inclusion of cohesion impacts in HSR assessment methodologies. However, there is no consensus on how these impacts should be measured. In addition, it is important to define the planning level at which cohesion effects are measured, as it may occur that simultaneously e.g. both a positive effect at the regional level and a negative effects at the national level would take place. Recent publications on this topic have highlighted the methodological advantages of spatial analysis to address these cohesion issues. In particular, accessibility analysis has special strengths to define how transport and development impacts are distributed across geographical areas or population groups, therefore including compatibility with cohesion objectives. In this context, this research work presents a methodology in which impacts on territorial cohesion of HSR investments are assessed using an accessibility approach. Cohesion impacts are assessed at different planning levels: local, regional, corridor and national levels, from the combination of graphical and statistical analyses, supported by a Geographical Information System (GIS). Hence, the influence of the planning level is assessed.