$6.5 billion Big Dig tunnel opens

A 1.3-mile tunnel that cost $6.5 billion opened Friday in Boston. The tunnel is part of the Big Dig project, which will bury a 10-lane interstate beneath the city at a cost of $14.6 billion.

The tunnel connects the Massachusetts Turnpike to Logan Airport and is one of the most expensive stretches of roadway in the United States. It reduces the time of the trip from downtown Boston to the airport from 45 minutes in traffic to about eight minutes.

“Boston, one of the oldest cities in the country, will soon have one of the most advanced highway systems in the world,” Mayor Thomas Menino said at a ribbon-cutting ceremony for the tunnel.

Planning for the Big Dig, officially called the Central Artery/Third Harbor Tunnel Project, began in 1983. The price tag for the project was $2.6 billion then. Cost overruns, most caused by unexpected construction challenges, have since brought the total to $14.6 billion.

Several portions of the project have been completed. The Ted Williams Tunnel opened in 1995 and the Leonard P. Zakim Bunker Hill Bridge opened last year. The main part of the project – putting the overhead Interstate 93 underground – is slated to be finished in early 2004.