ABSTRACT
The observation that investments in transportation infrastructure (including highways, rail, mass transit, ports and airports) generate accessibility, economic, environmental and social impacts, is hardly news for transportation economists and planners. Numerous studies have documented these impacts and, in general, have classified them as being adverse ones (e.g. air pollution, community displacement) or positive ones (e.g. job creation and economic growth). While it is generally agreed that improved accessibility should be the prime objective of transportation investments (Mohring, 1993), in many cases the presumed capability of a project to generate other positive impacts is regarded as the main motivation for undertaking the investment. Presently, in many countries, the alleged ability of transport infrastructure investment to enhance employment and promote economic development constitutes a major driving force behind governments’ propensity to allocate funds for such purposes.1
