The Weakest Link: A Model of the Decline of Surface Transportation Networks

This study explores the economic mechanisms behind the decline of a surface transportation network, based on the assumption that the decline phase is a spontaneous process driven by decentralized decisions of individual travelers and privatized links. A simulation model is developed with a degeneration process by which the weakest link is removed iteratively from the network. Experiments reveal how the economic efficiency of a network evolves during the degeneration process and suggest an 'optimal' degenerated network could be derived during the decline phase in terms of maximizing total social welfare. Keywords: decline, transportation network, degeneration, welfare, accessibility