MassDOT-FHWA Pilot Project Report: Climate Change and Extreme Weather Vulnerability Assessments and Adaptation Options for the Central Artery
The Massachusetts Department of Transportation (MassDOT) and the Federal Highway Administration (FHWA) commissioned a pilot project to assess climate change vulnerability of the Central Artery and Tunnel System (CA/T) for the City of Boston, Massachusetts in 2013 - 2015. Through sea level rise and storm surge modeling for Boston, the study found that this critical transportation system is highly vulnerable to flooding. The pilot team developed adaptation strategies for current and future implementation, and initiated an emergency response plan for tunnel protection.
Boston’s Central Artery/Tunnel System is comprised of 8 lane highways, more than 160 lane-miles, more than half of them in tunnels, six interchanges and 200 bridges. The research team determined that the lack of redundancy and the critical nature of each structure in the CA/T system make it potentially extremely vulnerable to sea level rise. The assessment indicates that the number and spatial extent of vulnerable structures increase over time as sea level rise and the intensity of storms increase, across this complex transportation system.
The hydrodynamic Boston Harbor Flood Risk Model was created to identify risk and depth of water resulting from storm surge-induced coastal flooding in Boston. This advanced model simulates the effects of tides, storm surge, wind, waves, wave setup, river discharge, sea level rise, and future climate change scenarios.
The CA/T team also developed Coastal Flood Exceedance Probability Maps and Estimated Flood Depth Maps for the 2013, the 2030 and the 2070/2100 climate scenarios. (These maps are provided to the public on the MassDOT website.)
Local, facility-based adaptations that are intended to improve resiliency of individual assets were identified and built into a local level adaptation plan for the CA/T. This strategy is described as generally conservative, meaning that the local protection for each structure and tunnel may not be the least expensive approach, but would provide adequate protection.
In order to assess viable regional adaptations, the flood risk maps were evaluated for each climate change scenario to identify key flood entry points and flood pathways along Boston Harbor. A summary of the locations identified for regional adaptations are shown in Table 6-3. The table presents an overview of each adaptation site, identifies the MassDOT facilities that would be protected by the adaptation measure, summarizes the upland flooding risk, and provides a recommended conceptual engineering adaptation and associated cost - including capital and annual maintenance estimates.
The FHWA's Climate Change Resilience Pilots program was implemented to build the FHWA's Climate Change and Extreme Weather Vulnerability Assessment Framework - which continues to be utilized in pilot projects nationwide.
Publication Date: June 2015
- Massachusetts Department of Transportation (MassDOT)
- Federal Highway Administration (FHWA)