Probabilistic risk assessment of hurricane-induced debris impacts on coastal transportation infrastructure

Hurricanes pose a significant challenge to the resilience of coastal communities, causing not only direct physical, social, and economic impacts but also indirect or cascading effects. Among these, debris-related impacts can cause structural damage from debris collisions and disrupt essential services by blocking roadways, thereby slowing the recovery of other infrastructures. As a result, it is essential to better understand and model debris and its uncertain impacts on coastal communities in the face of storm hazards. This paper puts forward a methodology to probabilistically evaluate hurricane-induced debris and its impacts on community-scale transportation infrastructure. Selected features of the proposed methodology are showcased using testbed community data and input models relevant to the Galveston region in Texas, USA. The findings highlight the need to account for debris impacts when assessing transportation network resilience metrics in coastal areas. Without this consideration, the impacts of such events, including equitable access to emergency facilities, could be underestimated. The results reveal that when debris and roadway damages are considered together, connectivity loss to emergency facilities could increase from 2% to 17% under a representative 500-year storm event.