Method for Ranking Relative Importance of Structures to Virginia’s Roadway Network

Abstract

In 2011, the Structure and Bridge Division of the Virginia Department of Transportation (DOT) requested assistance from the Virginia Transportation Research Council to develop a structure scoring tool that would rank the relative importance of Virginia DOT–maintained structures to the highway network and to the economy of Virginia. The new score was intentionally based exclusively on data related to the structure’s role in the highway system and is unrelated to structure condition or age. The new tool produces a structure score dubbed the “importance factor” (IF) for all open structures in the Virginia DOT’s current inventory database. IF scores are based on current data in the structure inventory database, supplemented by geopositional data that identify schools, hospitals, and fire or rescue stations within 3 mi of each eligible structure. The IF score adds the critical dimension of the structure’s role in the connectivity of the highway system and the economy of Virginia to other structure scoring tools that measure condition and age factors. IF scores are relative rankings of eligible Virginia DOT–maintained structures and have no standalone value. The scores may be updated each time a structure inventory database is refreshed. The staff of the Virginia DOT’s Structure and Bridge Division has incorporated this method into a multiobjective prioritization formula for Virginia structures in response to requirements related to a “state of good repair” in the Moving Ahead for Progress in the 21st Century Act. The new formula incorporates independent, normalized, dimensionless variables that address functionality, risk, importance, condition (health index), and cost-effectiveness. This method fulfills the importance component.