US Commuting delays from tidal flooding worsen with sea level rise

Although sea level rise is predicted to cause severe societal impacts at the end of the 21st century, few studies quantify the impacts coastal communities already face and empirical evidence regarding contemporary adaptive behaviors to these contemporary impacts remains limited. Here we combine complete road networks, historical and projected flood exposure, and the home/work locations of 500 million person-years for US coastal commuters to estimate the historic and projected delays due to SLR-related tidal flooding. We find that tidal flooding currently delays coastal commuters by an average of 22 minutes (+/- 4.4), increasing to 183 (+/- 33) to 643 (+/- 108) minutes by 2060 under current sea level rise scenarios. Furthermore, adaptive changes in residential and work locations from 2000-2015 reduced delays for coastal residents in 40% of U.S. counties. In the absence of policy, these commuting delays could lead to capital and residential flight from currently thriving coastal economic zones.