Unit costs for bridge preservation maintenance, improvement actions and user benefits are required for network-level analysis in the Pontis bridge management system (BMS). This report describes the process and results for establishing these values for the Minnesota Department of Transportation (Mn/DOT). Also provided were the transition probabilities for modeling deterioration for the bridge elements. Unit costs for preservation action performed by Mn/DOT maintenance crews were acquired from the Mn/DOT Estimating Unit. Work breakdown for maintenance actions and standard element definitions for converting cost units were developed as needed. Unit costs for preservation actions performed by contract were derived from cost data in the Mn/DOT Work Management System (WMS) warehouse through the Mn/DOT Bridge Maintenance table. Work codes in WMS were mapped to maintenance actions in Pontis. Estimates for bridge widening, raising, strengthening, and replacement costs were defined as were accident cost, vehicle operating cost, and travel time cost for calculating user-cost savings of functional improvement projects. A Windows program was developed to calculate weighted average unit cost for maintenance actions using data available in Mn/DOT's WMS warehouse. The program can be used to review maintenance costs and for on-going update of the Mn/DOT Pontis database.
