Massachusetts Turnpike in the context of "Tremont Street"

The Big Dig was a megaproject in Boston that rerouted the elevated Central Artery of Interstate 93 into the O'Neill Tunnel and built the Ted Williams Tunnel to extend Interstate 90 to Logan International Airport. Those two projects were the origin of the official name, the Central Artery/Tunnel Project (CA/T Project). The megaproject constructed the Zakim Bunker Hill Bridge over the Charles River, created the Rose Kennedy Greenway in the space vacated by the previous elevated roadway and funded more than a dozen projects to improve the region's public transportation system. Planning began in 1982 and construction was carried out between 1991 and 2006. The project concluded in December 2007.

The project's general contractor was Bechtel, with Parsons Brinckerhoff as the engineers, who worked as a consortium, both overseen by the Massachusetts Highway Department. The Big Dig was the most expensive highway project in the United States, and was plagued by cost overruns, delays, leaks, design flaws, accusations of poor execution and use of substandard materials, criminal charges and arrests, and the death of one motorist.

Worcester (/ˈwʊstər/ WUUST-ər, locally [ˈwɪstə] ) is a city in the U.S. state of Massachusetts. The principal city of Central Massachusetts, Worcester is both the second-most populous city in the state, and the 113th most populous city in the United States. Named after Worcester, England, the city had 206,518 people at the 2020 census, also making it the second-most populous city in New England, after Boston. Because it is near the geographic center of Massachusetts, Worcester is known as the "Heart of the Commonwealth"; a heart is the official symbol of the city. Worcester is the historical seat of Worcester County.

Founded in 1722 and incorporated in 1848, Worcester developed as an industrial city in the 19th century due to the Blackstone Canal and railways, which facilitated the import of raw materials and the export of such finished goods as machines, textiles, and wire. The city's population grew, driven by European immigration. After World War II, manufacturing in Worcester waned, and the city declined economically and in terms of population. This trend was reversed in the 1990s, when higher education, medicine, biotechnology, and new immigrants started making their mark. The population has grown by 28% since 1980, reaching its all-time high in the 2020 census, in an example of urban renewal. Since the 1970s, and especially since the construction of Route 146 and interstates 90, 495, 190, 290, and 395, both Worcester and its surrounding towns have become more integrated with Boston's suburbs. The Worcester region now marks the western periphery of the Boston–Worcester–Providence (MA–RI–NH) U.S. census Combined Statistical Area (CSA), or Greater Boston.

The Muddy River is a series of brooks and ponds that runs through sections of Boston's Emerald Necklace, including along the south boundary of Brookline, Massachusetts (a town that went by the name of Muddy River Hamlet before it was incorporated in 1705). The river is a protected public recreation area surrounded by parks and hiking trails, managed by the Massachusetts Department of Conservation and Recreation.

The river flows from Jamaica Pond through Olmsted Park's Wards Pond, Willow Pond, and Leverett Pond. It then flows through a conduit under Route 9 and into a narrow park called the Riverway, from which it flows through three culverts: the Riverway Culvert, the Brookline Avenue Culvert, and the Avenue Louis Pasteur Culvert. The Muddy River continues from the Fens toward its connection with the Charles River via the Charlesgate area, running through a stone-paved channel surrounded by a narrow strip of parklands. In a series of stone bridges and tunnels, it passes under Boylston Street, Massachusetts Turnpike, Commonwealth Avenue, Storrow Drive, and a series of elevated connecting ramps (the Bowker Overpass).