The Relative Index of Metropolisation of the Territory: Quantifying spatial reorganisation driven by land-based transport
提出了领土大都市化相对指数（RIMT），通过旅行时间和Delaunay三角剖分量化陆基交通网络引起的功能紧凑性，案例显示理论紧凑值达72.2%至98.2%，为规划者和政策制定者提供评估工具。
• RIMT quantifies the functional territorial compaction induced by transport networks. • Unbiased methodology uses Delaunay triangulation for objective, reproducible results. • Findings align with Tobler’s First Law, linking proximity and interaction. • A spatial metric that enriches the socio-economic assessment of land-based transport. • Applicability demonstrated across historical, consolidated, and prospective (Hyperloop) networks. The evolution of transport networks and modes drives dynamics of spatial reorganisation that facilitate the process known as territorial metropolisation, understood as the progressive integration of fragmented territories into operationally connected systems. The reduction of effective distances induced by transport infrastructures leads to improvements in mobility and accessibility which, from a functional perspective, translate into a theoretical compaction of territory and an increase in the intensity of socio-economic interactions. Despite its conceptual and empirical relevance, to date there has been a lack of a precise and objective quantitative measure capable of systematically characterising this functional compaction and reinforcing its significance as a key element of spatial reorganisation and, more broadly, of territorial metropolisation . This article presents the Relative Index of Metropolisation of the Territory (RIMT), a methodology designed to quantify this compaction induced by land-based transport infrastructures. The index is based on travel times between nodes and geometric techniques easily implementable in GIS environments, yielding a replicable, comparable measure free from parametrisation bias. The utility and scope of the RIMT are illustrated through four case studies: the road network in southern Michigan, the Haramain High-Speed Railway in Saudi Arabia, the Shinkansen network in Japan, and a prospective exercise concerning a Hyperloop network in Europe. The results show significant theoretical compaction of the connected surface (with values ranging from 72.2% to 98.2%), consistent with Tobler’s First Law of Geography, which links proximity to greater socio-economic interaction. The RIMT is proposed as a complementary resource to established territorial assessment tools, providing an explicit spatial dimension that enriches the analysis of the socio-economic impacts associated with land-based transport networks, and offering an additional tool for planners, policymakers and funding bodies.