Green Mobility Infrastructures. A landscape approach for roundabouts’ gardens applied to an Italian case study

The paper presents a multi-criteria method for unitary projects related to open spaces along urban road networks, with a focus on green spaces at roundabout intersections, considering them as integral part of broader landscape systems, and therefore as an opportunity for the construction of green infrastructures. The sprawl of road networks and the evolution of their types have gradually created a remarkable repertoire of new categories of open spaces, which, despite their often small size and residual nature, collectively can no longer be neglected. Innovative urban planning can transform these residual spaces into a distinctive feature of the city. Within this framework, we present a case-study on green spaces inside and adjacent to urban roundabouts in the City of Imola (Bologna), in the Emilia Romagna Region (Italy). They have been conceived as gardens, in order to enhance cultural values and foster a responsible use of environmental resources. The novelty of work lies in the holistic and cross-scale approach. Our proposal is based on a combination of multiple design issues (scenic values, landscape ecology, socio-economic sustainability) and specific characters of the context, with the aim of fulfilling aesthetic and functional requirements at the landscape level. The study defines spatial composition criteria, vegetation abacus and maintenance plans, articulated according to the various systems we identified and the following greening categories: Wild Flowers areas, Urban Groves, Rain Gardens, and Dry Gardens. We provide planning and design tools as guidance for further exploration. Concepts and guidelines we define enrich the discussion on mobility-related green spaces and integrate the few indications and instances on landscaping at roundabouts reported in the literature.