Senior Community Resilience with a Focus on Critical Transportation Infrastructures: An Accessibility-Based Approach to Healthcare

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.