PRIORITY PROGRAMMING FOR CONGESTED TRANSPORTATION NETWORKS. FINAL REPORT

A method for priority programming of interdependent alternatives in congested highway networks has been developed. Alternatives are considered interdependent if their benefits or costs are affected by other alternatives considered. A traffic assignment model is proposed for evaluating the network level impacts of various combinations of projects at different times. A graphical representation approach was developed to find the optimal solution for selecting and scheduling the projects. This approach is applicable in circumstances where traffic demand may be quite sensitive to changes in the network. By this representation, it is also relatively easy to identify the opportunity costs of making various decisions regarding the choice, sequence, and timing of possible projects. Visual presentations may be provided to support the decision making process. This methodology was demonstrated for the highway network of Calvert County, Maryland. Using several hypothetical improvement projects, the procedure assesses the existence of interdependencies and then applies the selection and scheduling method (i.e., graphical search algorithm) to each group of interrelated projects. The proposed methodology is shown to determine the best possible program. Several refinements are suggested to improve the proposed method.