No abstract

The AASHTO Pontis bridge management system has been used to support network-level and project-level decision making on the condition and functional obsolescence of bridges. State departments of transportation often develop bridge inspection data collection methods, deterioration models, cost models, and other preservation analysis capabilities to comply with the requirements of the federal Government Accounting Standards Board. The bridge health index (BHI) in the Pontis bridge management system has been used in the evaluation of the condition of bridges and elements at the project and network levels. This paper investigates three issues in the computation of the BHI: the effects of using linear and nonlinear scales for the condition state weights when computing the element health index (EHI); the application of amplification weights to EHI values to emphasize bridge elements in bad condition; and the development of element weights based on element replacement costs, element long-term costs, element vulnerability to hazard risks, and a combination of these measures. Historical condition data from element-based inspection were used to evaluate these effects at the network level.

No abstract

The importance of bridges to mobility in transportation is well known. However, the identification of bridges that influence the mobility of senior members of communities has not been evaluated. This is imperative because of human frailties associated with aging. In this paper, senior community resilience is assessed through accessibility of seniors to hospitals after bridge damage caused by hurricane events using Pinellas County in the Tampa Bay area as case study. The paper presents: (i) exposure probabilities for hurricane events at bridge locations; (ii) bridge damage state functions and damage state rating assignments using historical data from the National Bridge Inventory database; (iii) identification of bridges at risk of hurricane-induced damage; (iv) bridges identified as serving areas (census districts) with dense population of aging people; and (v) estimated effects of bridge closures on mobility and resilience of the aged population, based on accessibility to hospitals by using congested and free-flow travel times obtained from traffic assignment modeling. Findings showed that: (i) 66 bridges prone to hurricane-induced damage were observed to affect 140 selected aging population areas; (ii) bridge closures resulted in about 15% and 75% increase in free-flow and congested travel times, respectively; (iii) complete loss of accessibility to hospitals for some aging-dense zones; and (iv) resilience indexes of 0.94 and 0.81 were computed for free-flow and congested travel times, respectively. These results highlight significant loss in senior accessibility to hospitals and emphasize the need for policy discussions on the capabilities of highway bridges for efficient senior mobility.