Methods Used to Evaluate Highway Improvements

Abstract

This study provides information to state‐level planners for rational decision‐making regarding the enhancement of the analytical process for setting highway improvement priorities. Arizona's analytical procedure, a sufficiency rating scheme typically used by many states, is reviewed in light of the current problems facing decision‐makers. Four computerized alternative analytical techniques representing the state‐of‐the‐art are also reviewed. Sufficiency rating techniques are found to supply inadequate information regarding project benefits and the attainment of the improvement program objectives. Also, sufficiency ratings and utility functions are considered technically unsupportable because of their subjective base. Option‐evaluation techniques are found to supply valuable information regarding the user benefits generated by highway improvements. However, these techniques are limited in their scope of application and cannot incorporate all of the various project types or program goals into the improvement priority process. What is needed is a method which can evaluate the trade‐offs between various types of improvement projects on a comprehensive objective basis and evaluate improvement priorities against the multiple constraints and objectives which exist.