Characterizing Metro Networks: State, Form, and Structure

Document Type

Journal Article

Publication Date


Subject Area

land use - planning, ridership - commuting, mode - rail, mode - subway/metro


Strategies, Strategic planning, Rapid transit, Rail transit, Priorities, Objectives, Networks, Heavy rail transit, Graph theory, Goals


This paper seeks to characterize the network feature of metro systems by adapting various concepts of graph theory to define three characteristics of transit networks: state, form and structure. State measures the complexity of a network. Form investigates the link between metro systems and the built environment, distinguishing networks oriented towards regional accessibility, local coverage or regional coverage. Structure examines the intrinsic properties of current networks. The three characteristics are also linked to transit line type and land-use. The method presented is this paper is particularly useful at the strategic planning phase as it offers information on current and planned systems, which can then be used towards setting a vision, defining new targets and making decision between various scenarios. It can also be used to compare existing systems and identify paths of development.