There has long been a recognition that efficient transport plays a key role in supporting a dynamic economy and a high quality of life. However, traffic increases along with population and income, and traffic congestion and accidents are negative results of this increase, as is environmental damage. There has been a need for a methodology to evaluate user, nonuser benefits and the environmental impacts of transportation investments and policies through rational, objective scientific analysis.

This research aims to develop a methodology, termed the Transportation/Development Methodology, for evaluating transportation policies and projects, and also, to clarify the relationships between transportation investment and economic productivity. Transportation/Development Methodology, or TDM, conceptualizes the role of transportation in a broad socioeconomic and environmental context and enables scenario analysis.

In addition to the development of the TDM, this research comprises a critique and discussion of the primary methodologies used for evaluating transportation effects. In both transportation and development management, policy processes tend to proceed in nearly total isolation from ongoing planning activities in estimating impacts induced by transportation investments and policies. To overcome that imbalance for current models, TDM uses a system dynamics approach and adopts concepts from other methodologies, such as Input-Output analysis, the Lowry Model, and the Urban Transportation Planning Process (UTPP).

Finally, this research demonstrates the TDM by applying it in an analysis of a “real-life” situation, the Interstate 81 corridor, which goes through six states of the United States as a backbone of both passenger and freight transport. Development scenarios for improving regional economies, as well as for giving better service and reducing congestion, are analyzed by the TDM im order to evaluate their effectiveness. Application of the TDM to the I-81 corridor generates significant conclusions that would not have been possible using existing methodologies.