Urban and regional economic impacts of transportation investment: A critical assessment and proposed methodology

Macro-level studies of the effect of transportation infrastructure investment on regional economic growth have shown positive relationships between the level of public investment and the rate of private capital formation, employment, and output growth. At a microlevel, however, it is not quite clear how to model and measure the effects of an additional investment in a transportation facility like a highway or rail link on local economic growth. This issue is further exacerbated by the fact that negative environmental externalities from infrastructure expansion are mainly experienced at the urban and regional level and thus strongly affect their economic well being. Given these realities, this paper examines the critical issues involved in analyzing the economic effects of local infrastructure investments and then proceeds to propose a model which shows analytically the impact of changes in accessibility, caused by infrastructure expansion, on location and output decisions, and on the use of labor by production firms.