Optimizing System-Level Bridge Maintenance, Rehabilitation, and Replacement Decisions

摘要

An Optimum Budget Forecasting and Allocation System (OPBRIDGE), considering owner costs and user costs, was developed to determine the optimum improvement action and time for each individual bridge in a system under various levels of service goals and funding constraints over an analysis horizon. A bridge manager enters analysis horizon, minimum performance requirements, and policies as well as granted budget, maximum allowable budget, or unlimited budget for each year in the horizon. A granted or limited budget can be entered either as a total available or as distributed by line item to maintenance, rehabilitation, and replacement activities. OPBRIDGE extracts data from the bridge database and the cost and parameter file, and then optimizes decisions for every year in the analysis horizon using a 0-1 integer-linear programming formulation. At the end of every year, OPBRIDGE ages bridges one year and predicts condition ratings, ADT, etc. This allows the system to continue the analysis in the next year. Finally, OPBRIDGE produces detailed bridge-by-bridge output showing recommended current and future major actions, county-by-county output showing costs of major actions and budget required for each county, and tabular and graphical outputs showing the future performance level of the bridge system over the horizon.