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Massachusetts SuperGraphic

Boston's “Big Dig” - The Beginning

The most expensive highway project in U.S. history began in response to the notorious traffic congestion found in the heart of Boston's historic districts. The Central Artery/Tunnel Project known also as “The Big Dig” was an ambitious road improvement project to include tunnel construction under the Boston Harbor and downtown Boston and the creation of a new river crossing over the Charles River. The Boston Transportation Planning Review Board conceived the project in the 1970s and project planning officially began in 1982. Construction was kicked off in 1991 and roadways, tunnels and bridges were constructed and opened in phases throughout nearly two decades. The construction project was considered officially completed and closed on December 31, 2007 and is now unofficially known as “The Big Dug.”


In the mid 1900s Boston's inner city streets were excessively clogged and the idea was born to improve the streets – some of which were originally laid out in the early days of the Boston Township. An elevated expressway was constructed between Boston's downtown areas and the waterfronts to address the growing traffic problems of the times. Initially planned in the1920s and constructed in the 1950s, the John F. Fitzgerald Expressway, also known as the Central Artery, was constructed as a partly elevated and partly tunneled, six-lane divided highway. While some saw an improvement, others expressed dismay that the expressway physically divided the historical areas between the downtown and the waterfront. Thousands of residents and businesses were displaced during its construction and there was a general displeasure with the way the elevated expressway loomed large and separated neighborhoods.


By the end of the 1950s, the Dewey Square Tunnel was constructed underground at the southern end of the Central Artery. The expressway continued to grow more congested and options were considered to help improve the clogged Central Artery situation. Highway projects and improvements in the 1950s and 1960s were carried out with little consideration to surrounding communities or motorists in the path of the roadway construction work. To make improvements meant substantial disruption, dislocation and delays to motorists. In the 1970s, the Boston Transportation Planning Review began working on the concept of moving the entire expressway underground. Meanwhile, traffic problems continued to worsen and there was increased frustration for motorists and businesses. In 1959 the original Central Artery running through the center of downtown carried 75,000 vehicles a day, but by the early 1990s it carried more than 200,000 vehicles a day.  Boston was now known for having one of the most congested highways in the United States.



Problems of the Old Central Artery by the 1990s:

  • 1.   Traffic stalled and crawled for more than 10 hours a day for more than 200,000 motorists daily

  • 2.   The accident rate on the highway was four times the national average for comparable urban interstates

  • 3.   Problems of the two tunnels under Boston Harbor between downtown Boston and Boston's Logan International Airport added to the delays and frustrations of travelers

  • 4.   Annual costs to motorists was estimated at $500 million due to higher accident rates, wasted fuel from idling in stalled traffic and consequences of major delays

  • 5.   The elevated highway cut off Boston's North End and waterfront neighborhoods from the downtown, limiting their access and ability to contribute to the city's businesses

  • 6.   Local businesses arguably suffered economic losses due to the limited access

  • 7.   Major problems existed with the numerous number of entrances and exits, turns that were too tight, ramps without merge lanes, the increasing size of vehicle loads, and safety concerns of about roads built before strict federal interstate standards were developed

  • 8.   Environmental and aesthetic concerns mounted as the roads aged and deteriorated with the ever-increasing vehicle loads

  • 9.   Projections were that unless major improvements to the Central Artery and the harbor crossings were made, Boston could expect the traffic to inch along for at least 16 hours a day by the year 2010

  • 10.  On-going traffic jams and/or construction projects continued to impact the economy, environment and the quality-of-life of the citizens of Boston and New England



The graphic The Central Artery/Tunnel Project