The Federal Highway Administration (FHWA) has established measures for State departments of transportation to use for implementing the National Highway Performance Program (NHPP), which includes bridges that carry the National Highway System (NHS). Each State is required to develop an asset management plan to improve or preserve bridge conditions [1] and operation of a bridge management system that includes deterioration forecasting. The objective is to assist bridge owners in prioritizing and efficiently performing maintenance, preservation, and/or re-construction on bridges. Achieving this objective requires the use of bridge inspection data to estimate bridge deterioration over time and to identify bridge work that will maximize service life and returns on investment.

Representative deterioration curves specific to Montana’s climate, operation practices, and bridge design details are required to more accurately perform state-wide investment optimization alternatives. In addition, changes to deterioration trends based on maintenance, rehabilitation, or construction practices should be captured to reflect changes to bridge service life. The integration of the refined deterioration curves for Montana bridges must be compatible with a selected bridge management system.

The overall objective of the research is to develop deterioration curves for bridge elements in Montana. Specific objectives are to 1) Create families of deterioration curves for Montana bridges in different geographic locations using explanatory variables such as traffic volume, climate conditions, and design type, 2) Establish modifications to the deterioration curves to represent ‘performance jumps’ in bridge conditions created after maintenance or rehabilitation activities take place, and 3) Create a process to easily revise and implement the data with MDT’s bridge management software.