Using circuity as a network efficiency measure: the example of Paris

Abstract

Circuity, also called as the detour index or the route factor, is the ratio of the network distance between two points to the Euclidean or ‘as-the-crow-flies’ distance. This study aims to present a simple yet effective procedure to assess the transport network efficiency in and between different parts of an urban area using circuity and concentering partitioning. As an example, the road network of the city of Paris and its vicinity is examined using planar network data from OpenStreetMap. The variation in circuity levels is analyzed by quantifying the physical structure of the street network through the use of graph theory-based topological indices. The findings reveal that the beta index, or the average number of edges per node, and the order of a node, or the number of edges connecting to a node, plan a more important role in having more direct routes with less circuity in a road network. It is concluded that that the priorities in city planning affect the efficiency of transportation and the efficiency of the network can be assessed by a simple yet effective procedure based on circuity to guide policymaking.