Transportation Networks and Least-Cost Paths

Abstract

Abstract This chapter presents an overview of methods for reconstructing past transportation networks based on least-cost path (LCP) computations and different network models. After outlining the methodology for creating an LCP connecting two locations, several network models for linking a larger set of destinations by LCPs are introduced, most of these are derived from straight-line networks. LCP methods for detecting travel arteries with limited or no knowledge of the sites to be connected are presented as well. For instance, a least-cost hub-and-spoke network can be generated if only the hub location is known. Several models are tested in a hilly study region, east of Cologne, Germany, where the nodes are medieval settlements with a church or chapel located close to well-known old long-distance trade routes. The performance indicators of the network models are derived by calculating the lengths of LCP sections coinciding roughly with the known ancient routes. For the models applied, closeness as well as betweenness centrality of the nodes are computed, and the results are compared to the hubs in the known network.