Analysis of Interregional Commuters Traffic Delay Induced by Shoreline Protection of Different Areas of the San Francisco Bay Area

The effects of global climate change are already observed in coastal communities, and one of the key impacts of climate change is sea level rise (SLR). Such increases in sea level are expected to have large impacts on transportation infrastructure and result in region-wide commute disruption. Studies and adaptation strategies in coastal areas will allow decision-makers to take better actions against SLR. The present paper uses the San Francisco Bay Area as a case study. The study quantifies the interregional traffic delay of commuters due to the inundation of shoreline protection segments of the Bay Area. The approach is based on the marginal effect of protection within San Francisco Bay where individual stretches of coastline known as operational landscape units (OLUs) are protected one at a time. In the study, we integrate detailed shoreline scenarios, coastal inundation modeling, and traffic disruption modeling. Important insights from the analysis are obtained: the protection of an OLU (and specifically San Rafael OLU) will produce an average commute time reduction of up to 17% in the neighboring areas or the neighborhoods located across the bay. Five OLUs along with four bridges were identified as critical for minimizing disruptions to commute times. This methodology may be used by decision-makers when proposing adaptation and protection strategies that account for both local and regional areas.