Transportation planning.

• Author: Smith, Stephen C.
• Position: Projection Implications on the Economy

The demand for transportation services is based upon the relationship between land use and trip making. A large portion of travel is generated by interactions between population concentrations (as measured by households) which tend to produce trips and employment centers which tend to attract trips. A basic measure of travel demand is vehicle miles of travel (number of vehicles times distance traveled) or VMT. Based on the Indiana Department of Transportation's current population and employment forecasts (2000 to 2030) applied through the statewide travel demand simulation model, we see the total growth in VMT increasing 38 percent over that thirty-year period and truck-related VMT increasing by 85 percent. Freight-related traffic is expected to increase more rapidly than passenger traffic due to the increased dispersion of population and employment, increases in income driving demand for consumer goods and the longer trip lengths associated with the global economy.

The future population projections outline a continuation of recent trends in increased suburbanization and growth of the major metropolitan areas. This is resulting in a shift of travel patterns from the more traditional radial suburban-to-downtown business...