The MAP 21 infrastructure funding bill incorporates risk-based decision making to increase the effectiveness of how existing assets are managed. As part of the Federal Highway Administration’s (FHWA) Long-Term Bridge Performance (LTBP) research program the firm has been tasked with developing a data-driven performance index based on reliable, quantifiable data that incorporates our increasing awareness of how bridges actually perform and the risks of their dis-utility and failure. While this index may have subjective components like those associated with current bridge condition assessment, as the LTBP program expands its field data collection efforts, it is expected that this index will become increasingly objective in nature.
The Long-Term Bridge Performance Research Index is being developed as a part of the Long-Term Bridge Performance Program that represents each of the performance categories recognized by the FHWA Performance Primer, namely Functionality, Serviceability, Condition, Durability, System Integrity, Resilience, as well as “importance or essentiality” of the bridge. The Index will be applicable to the most common highway bridges in the NBI database, and will be a data-driven tool that includes heuristic knowledge and objectively measured performance characteristics. It will gradually minimize its reliance on subjective metric determinations as LTBP data becomes available. We have evaluated the sensitivity of the Research Index mathematical model employing readily available bridge condition data and based on this work, protocols will be developed for State DOTs to continue the validation of the Index.