While less damaging that storm surges, high tide flooding will increase with rising sea levels and affect traffic in many coastal areas. Often referred to as minor or a nuisance, HTF does not pose public safety risks, but can damage infrastructure such as roads, structures, and pipelines. These structures are being exposed to recurring environmental conditions, making them increasingly vulnerable to degradation, and leading to traffic delays. In a new study in the Journal of Infrastructure Systems, “Mere Nuisance or Growing Threat? The Physical and Economic Impact of High Tide Flooding on US Road Networks” expands on previous research on the road infrastructure in the contiguous U.S., beyond the East Coast, to include the Gulf and West coasts.

Authors Charles Fant; Jennifer M. Jacobs, M.ASCE; Paul Chinowsky; William Sweet; Natalie Weiss; Jo E. Sias, M.ASCE; Jeremy Martinich; and James E. Neumann, estimated the economic costs of traffic delays as a result of HTF, and explored various adaptation options that could make the road network more resilient. Specifically, they evaluated indirect adaptation options to alleviate these traffic delay costs; explored options to protect roads; and considered changes to maintenance costs.

Learn more about their study and the importance of road maintenance in the abstract below, or by reading the full paper in the ASCE Library, https://doi.org/10.1061/(ASCE)IS.1943-555X.0000652.


High tide flooding (HTF) already affects traffic in many US coastal areas, but the issue will worsen significantly in the future. While studies show that large storm surge events threaten to be ever more costly, less damaging, but more frequent HTF events remain understudied and potentially carry a comparable economic impact. This study advances our understanding of the risks and impacts of HTF on vulnerable traffic corridors using hourly tide gauge water levels, sea-level rise projections, and link-level spatial analysis. It is the first study to estimate HTF economic impacts for varying levels of intervention, including reasonably anticipated driver-initiated rerouting and ancillary protection of adjacent property. The 2020 annual national-level costs of $1.3 to $1.5 billion will increase to $28 to $37 billion in 2050 and $220 to $260 billion in 2100 for medium to high greenhouse gas (GHG) emissions scenarios, respectively. Total costs over the century are $1.0 to $1.3 trillion (discounted 3%). Additional cost-effective protection by building sea walls or raising road surfaces could significantly reduce 2100 costs to $61 to $78 billion, but there remain many barriers to adopting least-cost adaptation decisions, and these gains may only be realized with careful planning and information sharing.

Read the full paper in the ASCE Library: https://doi.org/10.1061/(ASCE)IS.1943-555X.0000652