ASSESSING SOCIAL COSTS FOR TRANSPORT ROUTE LOCATION.

Failure to include social and environmental costs in route location procedures has resulted in transportation routes receiving intense criticism. A mathematical statement of social costs within the overall transportation cost framework is formulated and considered operable for a study area, with subregions having approximately equal social costs per unit length. Actual social costs of nine variables are measured from field inventories of proposed California State Highway 52 in southwestern San Diego County. The nine variables are reduced to a set of three uncorrelated dimensions which, to a large degree, explain social costs. These dimensions are recreational, residential, and biotic. Composite factor scores are used to determine the lowest social cost route alignment and these scores are mapped.