In 1959, the people of Boston celebrated the opening of the Central Artery, an elevated section of Interstate 93 designed to carry cars and commerce swiftly across the city. Forty-five years later, they’re celebrating again, only this time it’s because the green steel and concrete artery — which turned into a traffic nightmare — is coming down.
The demolition heralds the beginning of the end of major work on the Central Artery/Tunnel Project, an enormous modernization of Boston’s transportation system. The old six-lane artery has been replaced by an eight-to 10-lane, two-tunnel underground I-93 expressway running directly beneath it.
Other major components of the 20-year-long project — also known as the Big Dig — include the extension of I-90 (the Massachusetts Turnpike) through South Boston, the Ted Williams Tunnel under Boston Harbor, five major interchanges along with access ramps to Logan International Airport, and two new bridges across the Charles River.
Altogether, the project spans 7.8 mi. (12.5 km) of highway and approximately 162 lane mi. (260 km), approximately half of which are in tunnels.
Bechtel and its joint venture partner, Parsons Brinckerhoff, have provided overall program management for the Big Dig.
By August 2004, the old 1-mi. (1.6 km) artery will be gone, restoring vistas that many residents have never seen and reuniting neighborhoods that have been separated for approximately half a century.
“It’s been astounding,” said Keith Sibley, manager, Bechtel Construction. “These were contiguous neighborhoods in the first half of the 1900s, until the highway bisected them. Now we’re reconnecting streets and knitting together the city and its waterfront.”
The replacement of Boston’s creaking transportation system also has paved the way to remaking the downtown area.
“Now that the old artery has come down, the transformation and what it could mean to Boston are fully apparent,” said David Luberoff, executive director of the Rappaport Institute for Greater Boston at Harvard University and co-author of Megaprojects: The Changing Politics of Urban Public Investment. “In a very real way this makes clear all of the opportunities that this project creates.”
Demolition of portions of the old elevated artery began in March 2003, after the opening of the new northbound Interstate 93 tunnel. At that time, only the decks and some of the framing for the northbound half of the artery could be removed. The teardown shifted into high gear in December, after the opening of the southbound I-93 tunnel removed the last traffic from the old artery.
Within hours, crews were demolishing a block-long section of the old roadway structure near Faneuil Hall and Quincy Marketplace, opening up a view across to Christopher Columbus Park and Boston Harbor.
In March 2004, crews dismantled the old double-deck truss bridge over the Charles River that was replaced by the visually stunning Leonard P. Zakim Bunker Hill Bridge — the widest cable-stayed bridge in the world — and the adjacent new Leverett Circle Connector Bridge.
The demolition of the old artery is itself a major project. It entails the removal of 36,300 tons (33,000 t) of steel, 12,100 tons (11,000 t) of concrete, and enough roadway deck to cover 28 football fields.
Complicating the work is the presence of potentially dangerous contaminants. The roadway edge sections, containing asbestos, must be abated and sent to landfills in New Hampshire and Maine. The steel skeleton, whose green paint contains lead, is being recycled.
In places where workers planned to cut the steel, they first had to remove the lead paint using recovery tools inside enclosures. Before dismantling the truss bridge, crews coated the entire structure with a polyurethane resin to prevent old lead paint from flaking off and falling into the river during demolition.
Improved views and reconnected streets aren’t the only benefits from tearing down the old artery. The noise generated by thousands of vehicles is gone.
Said one resident, “I never realized my neighbor was playing Christmas music.”
And then there are property values. Real estate experts predict that values of homes and condominiums that were in the shadow of the old artery could soar as much as 40 percent. They point out that a similar increase in property. values occurred in San Francisco when an unfinished elevated freeway was torn down, opening up views of the Bay to nearby neighborhoods.
Another reason why property values should increase: the demolition will create some 27 acres (11 ha) of open space along the old artery corridor — much of it for parks and gardens. That’s in addition to 40 acres (16 ha) of new parks in and around downtown Boston, and 100 acres (40 ha) at Spectacle Island in Boston Harbor, where the project has transformed an abandoned dump into a park.
For most Bostonians, however, improved views, higher property values, and quieter neighborhoods all take a back seat to the Big Dig’s main benefit — putting an end to a traffic nightmare.
Ironically, the old central artery was built to make it easy for drivers to get from one end of Boston to the other. Hailed as a “highway in the sky,” it was supposed to reinvigorate the city’s economy, which had flagged after World War II. When it opened, the elevated artery carried approximately 75,000 vehicles per day. But by the turn of the 21st century, the number had risen to approximately 200,000, and traffic crawled along for 10 hours each day.
The accident rate on the artery was four times the average for urban interstates. The problem already was apparent in 1982, when the state began to make plans for what would become the Big Dig. After environmental impact reviews were conducted in 1985, the U.S. Congress approved funding in 1987 for the basic scope of the project. Supplemental environmental impact reviews followed, and construction began in 1991.
In its initial form, the project was expected to cost over $2 billion in 1982 dollars, but inflation over time, accounting changes, a substantial expansion of scope, and environmental compliance and other, mitigation measures have increased the price tag to $14.6 billion.
The project began delivering on its promise in 1995 when the Ted Williams Tunnel opened, dramatically cutting the time it took to drive from South Boston to Logan Airport. The Leverett Circle Connector opened in 1999, followed by the Zakim bridge dedication in 2002.
Last year saw the opening of the new I-90 extension under the Fort Point Channel to the Massachusetts Turnpike as well as the underground sections of I-93 through downtown.
“For the longest time, the biggest part of what we were doing was invisible,” said Matt Wiley, Bechtel’s program manager of the Big Dig. “When we started to open the tunnels, we got comments like, ’Wow, we had no idea you were building something this extensive.’”
The new system of interstate-quality roads and bridges, augmented by improved ramps and reconfigured surface streets, has freed up traffic and significantly reduced the time it takes to traverse the city and commute from the suburbs.
It’s going to get better, according to officials of the Massachusetts Turnpike Authority. When the Big Dig is complete in 2005, it will feature high-occupancy vehicle lanes and a new fourth lane of traffic in each direction on the Zakim bridge. Also, there will be five lanes at the northern mouth of the Big Dig tunnel near the Fleet Center, and a completely reconstructed Dewey Square Tunnel. About the only thing missing will be the old central artery. And nobody is going to miss it.
(This article appears courtesy of “Bechtel Briefs.)