Comparing the Big Dig’s costs to mega projects around the world

Tunnels, highways, and rail lines cost billions no matter where you build them.

The price tag for Boston’s Big Dig ballooned from $2.6 billion to nearly $15 billion. And it was eight years behind schedule by the time it was done. How does that compare with some other mega construction projects around the world?

Related:10 years later, did the Big Dig deliver?


Gotthard Base Tunnel, Switzerland

  • Cost: $10 billion. At 35 miles, the tunnel in the Swiss Alps is the longest in the world. Scheduled to open in 2016. (At right, a worker exits an access tunnel for the project in Erstfeld, Switzerland, in this 2011 photo.)

Washington State Department of Transportation via Getty Images

Alaskan Way Viaduct, Seattle

  • Cost: $3.1 billion. Earthquake-damaged highway to be replaced by a tunnel. Under construction. (In this 2013 photo, a surveyor works in a tunnel that is part of the Seattle project.)

Jacquelyn Martin/AP/File

D.C. Metro Silver Line extension

  • Cost: $7 billion. New 23-mile rail line to Dulles International Airport. Under construction. (At right, riders wait for a train to depart a Metro station in Arlington, Virginia, in a 2007 photo.)

Peter Macdiarmid/Getty Images/File

London’s Crossrail

  • Cost: $23 billion. New city rail lines, 13-mile tunnel. Under construction. (A worker walks through a partially completed CrossRail station tunnel in this 2014 photo.)

Bebeto Matthews/AP/file

Second Avenue subway, New York City

  • Cost: $4.4 billion. New 8.5-mile transit line in Manhattan. Under construction. (Welders, shown in a 2014 photo, connect iron support bars during construction for the Second Avenue subway project.)

Gillian Allen/AP/File

The Chunnel, English Channel

  • Cost: $21 billion. A 31-mile rail tunnel connecting England and France. Completed in 1994. (The Chunnel work site in Dover, England, is shown at right in a 1990 photo.)

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