ROAD-RAT - REGIONAL RISK ASSESSMENT TOOL FOR FLOODING, EROSION, AND OVERTOPPING OF COASTAL ROADS

In many places, coastal roads are the first line of infrastructure impacted by coastal processes. Failure mechanisms for coastal roads include, e.g., undermining due to wave erosion, inundation, and erosion due to the weir-flow mechanism (Douglass, 2020). The damage and associated disruption can be either temporary or permanent and are, in principle, caused by the processes of erosion, flooding, and overtopping. The damages and disruptions are often costly and may have long-term effects for local residents, business, and rescue service access. Still, the knowledge about coastal risks on the road infrastructure is limited and risk analyses typically apply simplified approaches where only the still water level is taken into account. In this study, we develop a tool to assess the probability of impact from flooding, storm erosion, and overtopping on coastal roads, taking into account the long- term coastal evolution and the impact of sea level rise.