Known worldwide as the Big Dig, the project to revamp a central artery and tunnel in Boston, Massachusetts, USA, ranks as one of the country's most extensive and expensive highway projects, according to the U.S. Department of Transportation's Federal Highway Administration. Covering 7.8 miles (12.5 kilometers) of highway, it cost an estimated $14.6 billion in federal and state tax dollars. The project was originally conceived in the 1970s by the Boston Transportation Planning Review to improve the city's world-class traffic problem. Its main goal was to reroute Boston's elevated Interstate 93 into a 3.5-mile (5.6-kilometer) tunnel.
$14.B BILLION
The estimated amount of federal and state tax dollars spent on the Big Dig
$500 MILLION
The estimated annual cost to motorists from the previous congestion—in terms of an elevated accident rate, wasted fuel from idling in traffic and late delivery charges
200,00
The estimated number of vehicles using the central artery
INTERSTATE ISSUES
Quality issues surfaced throughout the project, including the discovery of leaking tunnels in September 2004. Then, in July 2006, a passenger on Interstate 90 was killed when approximately 12 tons of concrete plummeted from one of the tunnel's ceilings onto a car. The U.S. National Transportation Board determined the wrong epoxy had been used.
CONNECTING FLIGHT
The $1.9 billion Ted Williams tunnel extends Interstate 90 to Boston's Logan International Airport. The 1.6-mile (2.6-kilometer) bridge includes a 0.75-mile (1.2-kilometer) underwater section built using a dozen steel tube sections immersed into a trench on the Boston Harbor floor.
WE'RE READY FOR THAT
One of the project's biggest challenges was to keep construction going in the middle of downtown Boston without bringing the city to a standstill. To maintain traffic capacity and keep residences and businesses accessible throughout construction, the team introduced community liaisons, a 24-hour call center to handle complaints and incident reports, and a video-surveillance system to monitor traffic and construction.
BRING IN THE REPLACEMENTS
The $100 million, 10-lane Leonard P. Zakim Bunker Hill cable bridge was built over the city's Charles River to replace a deteriorating six-lane double-deck bridge.
OFF TARGET
The original quoted cost for the project was $10.8 billion—almost $4 billion less than the final tab on the project. A yearlong investigation by The Boston Globe revealed more than $1 billion of the overruns could be attributed to errors by the Big Dig's project management and design firm Bechtel/Parsons Brinckerhoff.
A HAPPY ENDING?
Despite the obstacles, the Massachusetts Turnpike Authority says the Big Dig has improved mobility in the city's infamously congested downtown area. The group estimates improved drive times will save $167 million annually in vehicle operation costs and time. The Boston Globe reports that since the project's completion, the average trip through the city's center has been slashed from 19.5 minutes to 2.8 minutes. The project has also reduced citywide carbon monoxide emissions by 12 percent, thanks in part to the creation of more than 260 acres of open land.
REWARD TIME
Last 5 November, the $13.3 million North End Parks of the Rose Fitzgerald Kennedy Greenway were officially dedicated on the former site of the elevated central artery. The three new acres (1.2 hectares) of green space in the heart of Boston will include a pool and gardens.
“This park is a long-awaited, much-deserved reward to our community and the people who have suffered through so much over the years of Big Dig construction,” said Salvatore F. DiMasi, speaker of the Massachusetts House of Representatives, at the ceremony.
3.8 MILLION CUBIC YARDS
The amount of concrete used for the project
NOT QUITE OVER
Although the project officially closed in 2007, only one of the 15 Big Dig contractors and agencies being sued by the family of the passenger killed in July 2006 has settled. The city of Boston and the state of Massachusetts have also filed a multimillion-dollar lawsuit against Bechtel/Parsons Brinckerhoff, claiming negligence during the project. Power Fasteners Inc., the company responsible for the epoxy glue, agreed to a $6 million settlement with the family last December, but still faces one count of involuntary manslaughter.