From railways to greenways: a complex index for supporting policymaking and planning. A case study in Piedmont (Italy)

Since the 1960s, a significant percentage of railway networks have been closed all over the world. This represents a heritage that can be used to provide new features to local communities with regard to sustainable development and landscape regeneration processes. Disused railways can be converted into greenways which are only dedicated to not motorized users and people with reduced mobility. Greenways can also be utilized for leisure, tourism and commuting. The growing interest and social demand for greenways face an obstacle in the form of scarce public funds. Accordingly, decision-makers and land-use planners need to assess the potential benefits and costs for local communities as well as the attractiveness for users. In this paper, we aim to provide a transferable working tool able to support decision-making and land-use planning processes related to the conversion of disused railway lines into greenways in mixed urban-rural contexts. We tested the developed methodology in Piedmont (Italy), a region with almost 600 km of abandoned railway lines and over 200 disused stations. We used a Geographic Information System (GIS) to carry out the spatial data analysis and an analytic hierarchy process (AHP) for integrating the preferences of stakeholders. We defined the Greenway Suitability Index (GSI), a synthetic global index able to take into account and synthetize the characteristics and current conditions of the disused railway networks and the territorial and social contexts (“Natural elements,” “Historical-Cultural resources,” “Traditional food and local wine”, “Landscape or Scenery,” “Accessibility,” and “Population”). Decision-makers can use the GSI to prioritize and concentrate the investments on the sections with the highest score. We defined four scenarios based on the desired prevalent use of the future greenways - namely, touristic versus recreational/daily travel. We then calculated the GSI for each of them in order to verify how the priorities can change in relation to the objectives. The successful application demonstrated that the methodology can be used to calculate a sort of “priority score” considering the stakeholder’s preferences and allowing for the land-use decision-makers to concentrate their investments in a hierarchal way.