Bridge Engineering Center

About the research

The Moving Ahead for Progress in the 21st Century Act (MAP-21) of 2012 requires states to develop and implement a transportation asset management plan (TAMP) for their respective portions of the National Highway System (NHS). Life-cycle cost and risk management analyses must be included in a state’s TAMP. As defined in the 1998 Transportation Equity Act for the 21st Century (TEA-21), life-cycle cost analysis (LCCA) is “a process for evaluating the total economic worth of a usable project segment by analyzing initial costs and discounted future costs, such as maintenance, user costs, and reconstruction, rehabilitation, restoring, and resurfacing costs, over the life of the project segment.”

The main objective of this research project was to develop a LCCA tool for Iowa’s bridges based on survival analysis of condition ratings. This tool was designed to cover the most common types of bridges in Iowa while integrating historical data from maintenance crews, contractors, and past inspections into the predictive models that account for the costs of maintenance and repair during a bridge’s service life.

The tool developed in this project provides a user friendly way to evaluate and compare maintenance costs for bridge decks over the lifetime of a bridge. With this information, transportation investment decisions can be made in consideration of all of the maintenance costs incurred during the period over which the maintenance alternatives are being compared.