Underground space in metro area: constituent, influencing factors and improving strategies of the spatial vitality

Nowadays, the shortage of available urban land and the booming construction of urban subway are driving the rapid development of Underground Space in the Metro Area (USIMA) which is an important constituent in the compact development of cities. Spatial vitality, as one of the most important evaluation indicators for the layout of such metro-related underground space, is closely related to spatial efficiency. Therefore, taking Shanghai People’s Square Metro Station (SPSMS) as a case study, this paper investigated the variable factors of the spatial vitality in USIMA by using methods of space syntax, field investigation, and pedestrian counting. Results revealed that the spatial vitality of USIMA is comprehensively affected by related variables, including accessibility and visibility of spatial configuration, degree of functional mixture, layout of station hall as well as entrances/exits, and the organization of business forms. Finally, improvement suggestions and discussions are put forward from the aspects of entrance/exit layout, spatial organization, and functional distribution, to provide reference for future planning, design and optimization of USIMA with effective vitality.