Profiling structurally deficient bridges in the United States: Sampling bridge performance data for qualitative trends

Long-term bridge performance data available in the NBI database was used to identify statistical trends between several qualitative and quantitative performance criteria that correlate to higher or lower prevalences of structural deficiency in US bridges. An internet-based resource which compiles and inventories all bridge inspection data for all bridges, nationwide into a single, interfaced LTBP database "Bridge Portal". The approach is to extract data on bridge material, climate, span length, average daily traffic volume, and ownership for structurally deficient bridges and to compare and correlate the sampled data from the total bridge population nationwide. A method is designed to process this data through several normalization and adjustment filters that correct for sample size and account for structural age, which is the final parameter. The advantage of this approach is that it separates deficiency from basic structural and material assumptions and includes other relevant factors that might not otherwise have been considered or previously explored in such detail. Analysis results and implications of these results to the present and future conditions of the United States' bridge infrastructure network are presented.