Engineering Inc. - July/August 2007 - 17

Before Massachusetts turnpike authority After once a mass of elevated highway ramps, north end Park, part of Boston’s Rose Fitzgerald Kennedy greenway, will open in spring 2008 (top right). A series of 14 parks will cut through the city from Causeway to Kneeland Streets (above). supporting the bridge and two cantilevered on the east side. It is designed to withstand 400 mph winds and a magnitude 7.9 earthquake. Throughout the Big Dig, engineers had to keep cars flowing. “It was essential to understand how every aspect of the project would affect traffic patterns and driving conditions,” explains John J. Kennedy, a traffic consultant with Watertown, Mass.based Vanasse Hangen Brustlin, Inc. “We had to make sure that total coordination existed among various contractors and government agencies.” Engineers rerouted traffic daily and, almost without exception, improved traffic flow during the construction phase, he recalls. At its peak, the Big Dig employed nearly 5,000 construction workers. The management team of Bechtel Corp. and Parsons Brinckerhoff oversaw 38 design contracts and 119 construction contracts involving 109 companies. “It was a very schedule-driven project that required tremendous synchronization of people and resources,” explains William J. Rizzo, former CEO and president of Tetra Tech Rizzo, which handled the engineering for two interchanges along I-93. “We had people from different companies— with entirely different cultures—working together [in a joint venture] to achieve a mutual goal.” On Jan. 18, 2003, officials raised the sign on I-90 and opened the last section of the 3,462-mile link to Seattle. A year later, workers dismantled the old I-93 structure and began replacing it with 300 acres of parks and plazas. “Removing the raised roadway has reinvented and reknitted the city,” Bertoulin says. “It has helped create an attractive urban environment that otherwise wouldn’t have been possible.” Leaving a Legacy Though the Big Dig has distinguished itself as an engineering marvel on par with the Panama Canal, Europe’s Chunnel and the Hoover Dam, its accomplishments are not without controversy. At $14.6 billion, the Big Dig is the most expensive highway project in history and its eventual price tag—more than $12 billion above the initial estimate—has left some citizens and government officials angry and dissatisfied. The Massachusetts Turnpike Authority filed a $146 million breach-of-contract lawsuit in 2004 over cost increases and other lingering issues, including outstanding legal and insurance claims, with the Commonwealth of Massachusetts. ACEC/ Massachusetts is now sorting through the mess. “It’s a complex matter that will take years to resolve,” Leathers says. The project also endured its share of tragedies. Sadly, four workers died while building the tunnels and infrastructure. In July 2006, a motorist passing through the I-90 connector tunnel was killed after bolts failed and a 12-ton concrete slab fell atop her vehicle. The tunnel was closed for five months while workers replaced the panel’s anchor. Later, Thomas F. Reilly, attorney general for Massachusetts, filed 15 lawsuits against firms that he accused of negligence in the ceiling collapse. Nevertheless, the Big Dig left a remarkable imprint on Boston. With 7.8 miles of highway and 161 total lanes, it has greatly reduced traffic, accidents and air pollution. A new park—the Rose Kennedy Greenway—will accommodate joggers, picnickers, workers on lunch breaks, local residents walking dogs, and children at play. And the Boston waterfront, now reconnected to the city, is enjoying an economic boom. “It is a terrific example of engineering excellence and innovation. It will be a case study for building large public projects,” says Abbie R. Goodman, executive director of ACEC/Massachusetts. The legacy extends far beyond Boston. “Many of the design and engineering methods used for the Big Dig have been picked up and applied to other projects around the world,” Bertoulin explains. And although some techniques are so specialized that they haven’t yet made their way into mainstream engineering projects, the innovation and lessons learned have proved invaluable. “That’s the nature of engineering and construction,” Bertoulin says. “Every project draws on the knowledge gained from previous projects, and everyone benefits.” n Samuel Greengard is a business and technology writer based in West Linn, Ore. July / AuGust 2007 ENGINEERING INC. 17

Engineering Inc. - July/August 2007

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