Editing Big Dig (section)

=== Cancellation of the Inner Belt project ===
[[File:Boston CAT Project-construction view from air.jpeg|thumb|The [[Leonard P. Zakim Bunker Hill Memorial Bridge|Zakim Bunker Hill Bridge]] over the Charles River under construction, looking north. The old elevated Central Artery crossing is to the right.]]
Another important motivation for the final form of the Big Dig was the abandonment of the Massachusetts Department of Public Works' intended expressway system through and around Boston. The Central Artery, as part of Mass. DPW's Master Plan of 1948, was originally planned to be the downtown Boston stretch of [[Interstate 95 in Massachusetts|Interstate 95]], and was signed as such. A bypass road called the Inner Belt, was subsequently renamed [[Interstate 695 (Massachusetts)|Interstate 695]]. The [[Federal-Aid Highway Act of 1956|law establishing the Interstate highway system was enacted in 1956.]]<ref name="Boston's Cancelled Highways">{{cite web |title=Boston's Cancelled Highways |url=http://www.bostonstreetcars.com/bostons-cancelled-highways.html |website=Boston Streetcars |access-date=January 28, 2019}}</ref>

The [[Inner Belt District]] was to pass to the west of the downtown core, through the neighborhood of [[Roxbury, Boston|Roxbury]] and the cities of [[Brookline, Massachusetts|Brookline]], [[Cambridge, Massachusetts|Cambridge]], and [[Somerville, Massachusetts|Somerville]]. Earlier controversies over impact of the Boston extension of the [[Massachusetts Turnpike]], particularly on the heavily populated neighborhood of [[Brighton, Boston|Brighton]], and the additional large amount of housing that would have had to be destroyed, led to [[freeway and expressway revolts|massive community opposition]] to both the Inner Belt and the Boston section of I-95.<ref name="Boston's Cancelled Highways"/>

By 1970, building demolition and land clearances had been completed along the I-95 right of way through the neighborhoods of Roxbury, [[Jamaica Plain]], the South End and [[Roslindale]]. This led to secession threats by [[Hyde Park, Boston|Hyde Park]], Boston's youngest and southernmost neighborhood, which I-95 was also slated to go through. By 1972, with relatively little work done on the [[Southwest Corridor (Boston)|Southwest Corridor]] portion of I-95 and none on the potentially massively disruptive Inner Belt, Governor [[Francis Sargent]] put a moratorium on highway construction within the [[Massachusetts Route 128|Route&nbsp;128]] corridor, except for the final short stretch of Interstate 93. In 1974, the remainder of the Master Plan was canceled.

With ever-increasing traffic volumes funneled onto I-93 alone, the Central Artery became chronically gridlocked. The Sargent moratorium led to the rerouting of I-95 away from Boston around the Route&nbsp;128 beltway, and the conversion of the cleared land in the southern part of the city into the [[Southwest Corridor Park|Southwest Corridor linear park]], and a new right-of-way for the [[Orange Line (MBTA)|Orange Line]] subway and [[Amtrak]].<ref>{{cite web |title="Decisions Touching the Lives of All of Us": The Plan That Changed Boston Forever |url=http://transitcenter.org/2016/06/22/massachusetts-governor-decides-transit-good-highways-bad/ |website=TransitCenter |access-date=January 28, 2019|date=June 23, 2016 }}</ref> Parts of the planned I-695 right-of-way remain unused and under consideration for future mass-transit projects.

The original 1948 Master Plan included a Third Harbor Tunnel plan that was hugely controversial in its own right, because it would have disrupted the [[Maverick Square]] area of [[East Boston]]. It was never built.<ref>{{cite book |author1=Federal Highway Administration |author2=Massachusetts Department of Public Works |title=Third harbor tunnel, interstate 90/central artery, interstate 93: full environmental impact statement and final section 4(f) evaluation |date=August 1985 |url=https://archive.org/stream/thirdharbortunne01mass/thirdharbortunne01mass_djvu.txt}}</ref>