This study was prompted by the impending prioritization of Washington State Department of Transportation (WSDOT) highway mobility projects for the 1997-1999 biennium. The ranking procedure that was analyzed and refined in the study is based on a methodology called "Technique for Order Preference by Similarity to Ideal Solution," commonly known as TOPSIS; it is the final step in WSDOT's current process for prioritizing proposed projects.
The report used the WSDOT programming method as a case study of one flexible framework for assessing projects related to all highway modes. Rank order sensitivity to estimate errors and to various categorical weight distributions was investigated. Furthermore, direct comparisons were made between the WSDOT priority programming method, a WSDOT systems planning method, and a Puget Sound Regional Council project prioritization method. The goals of the report were to inform the policy making debate over assigning subjective category weights and selecting pertinent categories of criteria, and to investigate the range of acceptable error in project performance predictions. In so doing, the reliability and adequacy of the WSDOT ranking methodology was also assessed.