What is sustainable transport infrastructure?

Abstract

Paper presented at the 32nd Annual Southern African Transport Conference 8-11 July 2013 "Transport and Sustainable Infrastructure", CSIR International Convention Centre, Pretoria, South Africa.

This paper commences with a review of economic growth theory noting the key role of technology, deployed via appropriately regulated institutions. It applies these insights to the transport infrastructure sector in order to answer the question: how can transport technologies, or modes, be deployed most sustainably in terms of their contribution to economic growth and prosperity? Sections follow which explore how transport technologies and the institutional forms by which they are delivered, differ in terms of the efficiency with which they are able to transmit economic value. Reference is made to time series data comparing rail and paved roads investment in South Africa from 1875-2005 to GDP data showing that the economic impact of rail investment has declined relative to that of road from about 1930, despite protection of the rail sector. This GDP impact differential is explained in terms of the positive economic externalities of road transport technology relative to rail technology. The externalities include: ability to elicit viable economic activity: at smaller scales, in a wider range of locations, and in support of more efficient manufacturing technologies, than rail transport could sustain. The role of institutional form in the procurement and delivery of transport infrastructure is then considered, noting how reforms in the rail sector in different parts of the world have generally occurred in order to redeploy rail transport technology to sectors in which it can continue to transmit economic value efficiently. It is reported that when such reform has been resisted, the economic role of rail becomes increasingly unsustainable. Finally, a definition of a sustainable transport infrastructure strategy is offered as one in which each transport infrastructure technology, or mode, is used where its technological strengths can be effectively deployed, and requiring institutional forms that are mandated to ensure that positive externalities are optimised and negative externalities minimised.