Recent legislative and regulatory actions require major investment analyses of transportation projects prior to construction. These analyses must respect the intermodal consequences of proposed actions. The most commonly applied transportation investment analysis methods apply to specific modes and funding circumstances. The lack of a comprehensive investment evaluation methodology impedes advancement of intermodal and multi-modal transportation system development. Benefit-cost analysis may offer the best opportunity for fairly assessing the investment worthiness of transportation projects with multi- and intermodal impacts. Initial investigation of the feasibility of the benefit-cost approach finds it superior to the two most popular current methods, the Federal Transit Administration's cost effectiveness index, and the American Association of State Highway and Transportation Officials' user benefit analysis. Major technical hurdles to implementation of benefit-cost analysis are modal limitations in travel forecasting and development of cost factors for environmental impacts. A subsequent phase of this study will compare the benefit-cost approach to other methods by applying the various techniques to five transportation alternatives in the Oklahoma City region.