Charles River Crossing - The Mitigation Plan

The Central Artery/Tunnel (CA/T) Project is the largest public infrastructure project in the United States. Following ten years of environmental review and analysis, the Project has now moved through the design phases into construction. One of the more daunting tasks for the Project was planning and designing the crossing of the Charles River between Boston, Cambridge and Somerville, Massachusetts. The Crossing represented one of the most complex design and construction challenges and was the single-most contentious portion of the CA/T Project. The Project includes the highway elements connecting the major north/south interstate-Route I-93 - to the state highway system and downtown Boston and was needed to improve one of the most hazardous accident locations in the country. The design development had to accommodate several complicated transportation elements and occurs in an area characterized by challenging physical features, major public infrastructure facilities, sensitive environmental resources and aesthetic concerns. This paper discusses the means by which Project staff worked with local, state and federal agencies as well as several diverse stakeholders in refining the Project design and developing a workable mitigation plan to offset Project impacts in this area.