Editing Big Dig (section)

== Origin ==
[[File:OnBostonsElevatedCentralArtery.agr.jpg|thumb|Traffic on the old, elevated Central Artery at midday, 2003]]
This project was developed in response to traffic congestion on Boston's historically tangled streets, which were laid out centuries before the advent of the [[automobile]]. As early as 1930, the city's Planning Board recommended a raised express highway running north–south through [[Downtown Boston|the downtown district]] in order to draw through-traffic off the city streets.<ref>Daily Boston Globe, December 21, 1930 'Streets In The Air Only Solution To Boston's Traffic Problems So Says the Planning Board That Asks for Two-Level Road Across City, Costing $28,000,000, as First Item in a Big Scheme'</ref> Commissioner of Public Works [[William F. Callahan|William Callahan]] promoted plans for the Central Artery, an elevated expressway which eventually was constructed between the downtown area and the waterfront.<ref name="CEG"/>

In the 1950s, Governor [[John Volpe]] interceded to change the design of the last section of the Central Artery, putting it underground through the [[Dewey Square Tunnel]]. While traffic moved somewhat better, the other problems remained. There was chronic congestion on the Central Artery (I-93), the elevated six-lane highway through the center of downtown Boston, which was, in the words of Pete Sigmund, "like a funnel full of slowly-moving, or stopped, cars (and swearing motorists)."<ref name="CEG">{{cite news |last=Sigmund |first=Pete |date=June 6, 2007 |title=Triumph, Tragedy Mark Boston's Big Dig Project |url=http://cegltd.com/story.asp?story=8751&headline=Triumph,%20Tragedy%20Mark%20Boston%E2%80%99s%20Big%20Dig%20Project |url-status=dead |archive-url=https://web.archive.org/web/20141006135142/http://cegltd.com/story.asp?story=8751&headline=Triumph,%20Tragedy%20Mark%20Boston%E2%80%99s%20Big%20Dig%20Project |archive-date=October 6, 2014 |access-date=December 10, 2007 |publisher=Construction Equipment Guide}}</ref>

In 1959, the {{convert|1.5|mi|km|adj=mid|-long|abbr=off|sp=us}} road section carried approximately 75,000 vehicles a day. By the 1990s, this had grown to 190,000 vehicles a day. Traffic jams of 16 hours were predicted for 2010.<ref>{{Cite web |url=https://www.mass.gov/info-details/the-big-dig-project-background |title=The Big Dig: project background |author=Massachusetts Department of Transportation (MassDOT) Highway Division |access-date=March 30, 2019 }}</ref>

The expressway had tight turns, an excessive number of entrances and exits, entrance ramps without merge lanes, and as the decades passed and other planned expressways were cancelled, continually escalating vehicular traffic that was well beyond its design capacity. Local businesses again wanted relief, city leaders sought a reuniting of the waterfront with the city, and nearby residents desired removal of the matte green-painted elevated road, which mayor [[Thomas Menino]] called Boston's "other [[Green Monster]]", as an unfavorable comparison to [[Fenway Park]]'s famed left-field wall.<ref>{{Cite news| agency=Associated Press | url=https://www.nbcnews.com/id/wbna3769829 | title=Boston's 'Big Dig' opens to public | work=NBC News | date=December 20, 2003 | access-date=March 30, 2019}}</ref> [[Massachusetts Institute of Technology|MIT]] engineers Bill Reynolds, and eventual state Secretary of Transportation [[Frederick P. Salvucci]] envisioned moving the whole expressway underground.<ref>{{Cite web|title=After 20 Years, the End Is Near for Boston's Big Dig|url=http://www.kitsapsun.com/opinion/after-20-years-the-end-is-near-for-bostons-big-dig-ep-423883076-359516211.html|access-date=2021-01-11|website=www.kitsapsun.com|language=en}}{{dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{Cite news|last=McNichol|first=Dan|date=2004-07-25|title=Hub Guide / Getting Around; Big Dig Nearing Light of Costly Tunnel's End (Published 2004)|language=en-US|work=The New York Times|url=https://www.nytimes.com/2004/07/25/news/hub-guide-getting-around-big-dig-nearing-light-of-costly-tunnel-s-end.html|access-date=2021-01-11|issn=0362-4331}}</ref>

=== 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>

=== Mixing of traffic ===
A major reason for the all-day congestion was that the Central Artery carried north–south traffic and east–west traffic. Boston's Logan Airport lies across [[Boston Harbor]] in East Boston. Before the Big Dig, the only access to the airport from downtown was through the paired [[Callahan Tunnel|Callahan]] and [[Sumner Tunnel|Sumner]] tunnels. Traffic on the major highways from west of Boston—the Massachusetts Turnpike and [[Storrow Drive]]—mostly traveled on portions of the Central Artery to reach these tunnels. Getting between the Central Artery and the tunnels involved short diversions onto city streets, increasing local congestion.

=== Mass transit ===
A number of [[public transportation]] projects were included as part of an [[environmental mitigation]] for the Big Dig. The most expensive was the building of the Phase II [[Silver Line (MBTA)|Silver Line]] tunnel under [[Fort Point Channel]], done in coordination with Big Dig construction. Silver Line buses now use this tunnel and the Ted Williams Tunnel to link [[South Station]] and Logan Airport.

Construction of the [[Massachusetts Bay Transportation Authority|MBTA]] Green Line [[Green Line Extension|extension beyond Lechmere]] to [[Medford/Tufts station]] opened in December 2022.<ref>{{cite web |title=Green Line Extension Project |url=https://www.mbta.com/projects/green-line-extension-glx |url-status=dead |archive-url=https://web.archive.org/web/20230306145552/https://www.mbta.com/projects/green-line-extension-glx |archive-date=March 6, 2023 |access-date=March 25, 2023 |website=MBTA Main Site |publisher=Greenlineextension.org}}</ref> {{As of|2023}}, promised projects to connect the [[Red Line (MBTA)|Red]] and [[Blue Line (MBTA)|Blue]] subway lines, and to restore the Green Line streetcar service to the [[Forest Hills (MBTA station)|Arborway]] in [[Jamaica Plain]] have not been completed. The Red and Blue subway line connection underwent initial design,<ref>[http://www.eot.state.ma.us/redblue/ Red Line / Blue Line Connector] {{webarchive |url=https://web.archive.org/web/20140105024145/http://www.eot.state.ma.us/redblue/ |date=January 5, 2014 }}</ref> but no funding has been designated for the project. The [[Green Line E branch|Arborway Line restoration]] has been abandoned, following a final court decision in 2011.<ref>{{cite news |url=http://jamaicaplaingazette.com/2011/08/26/trolley-comeback-killed-by-court/ |title=Trolley comeback killed by court |newspaper=Jamaica Plain Gazette |author=Ruch, John |date=August 26, 2011 |access-date=February 19, 2013 |url-status=live |archive-url=https://web.archive.org/web/20131229004250/http://jamaicaplaingazette.com/2011/08/26/trolley-comeback-killed-by-court/ |archive-date=December 29, 2013 }}</ref>

The original Big Dig plan included the [[North-South Rail Link]], which would have connected North and South Stations, the major passenger train stations in Boston. This aspect of the project was dropped by the state transportation administration early in the [[Michael Dukakis|Dukakis]] administration. Negotiations with the federal government had led to an agreement to widen some of the lanes in the new harbor tunnel, and accommodating these would require the tunnel to be deeper and mechanically vented. This left no room for the rail lines. Diesel trains, then in use, passing through the tunnel would have substantially increased the cost of the ventilation system.<ref name="Haglund2003">{{cite book|last1=Haglund|first1=Charles|title=Inventing the Charles River|date=2003|publisher=MIT Press|isbn=0-262-08307-8|page=[https://archive.org/details/inventingcharles00hagl/page/316 316]|url-access=registration|url=https://archive.org/details/inventingcharles00hagl/page/316}}</ref>