The surprises included uncharted utilities, archeological discoveries, ground-water conditions, environmental problems, weak soil, and hazardous materials. The sheer size of this project and the fact that construction occurred in a busy city resulted in having to deal with many unanticipated conditions and a large volume of claims and changes. Project documents show that the challenges of subsurface conditions were substantially underestimated. The most difficult problems on the Big Dig involved the means and methods used to address issues raised in the project’s design and drawings, and the failure to properly account for subsurface conditions during the construction process. Research shows that mega-project costs are consistently underestimated, a practice often attributed to the desire of project advocates to have their projects approved. Some of the increase can be attributed to an unrealistic initial cost estimate. The Big Dig reported that about half the cost growth was caused by inflation, but official inflation rates over the life of the project do not support the claim. Using preliminary Big Dig data, we studied the impact of inflation, often claimed to be a major cost-escalation factor.
The critical cause was a lack of experience and knowledge about dealing with the complexity and uncertainty that giant projects bring with them. Multiple decisions by project management across all contracts contributed to the increases. Our research on the Big Dig has shown us that no single catastrophic event or small number of contracts caused costs to escalate.
#THE BIG DIG FALLOUT 4 HOW TO#
To address major problems in mega-project management, Boston University, through its Mega-Project Research Program, has begun researching mega projects to help understand current practices, develop new practices and frameworks, and learn how to prevent or reduce risks before they cause serious problems or even project failure. Photo Credit: Rene Schwietzke Causes of Cost Escalation These included an owner-controlled insurance program that saved $500 million by providing group coverage for contractors, subcontractors, and designers and an unprecedented safety program a cost-containment program that saved $1.2 billion an integrated audit program that identified and mitigated existing and potential overruns and delays a labor agreement that established a no-strike, no-slowdown guarantee for the life of the project a quality-assurance program that was recognized by the Federal Highway Administration as one of five noteworthy accomplishments and a dispute-resolution process that avoided extensive litigation costs.Ībove: Interstate 93 tunnel in Boston, part of the Big Dig. Few infrastructure projects have used as many innovative tools and programs to control project risk and cost as the Big Dig. In other words, things can go dramatically wrong despite the best efforts.
Nonetheless, costs increased across all contracts throughout the project’s life cycle despite enormous efforts to transfer, mitigate, or avoid risk and contain costs. Extensive environmental feasibility studies, risk assessments, and other documentation were completed prior to the project’s start. The Big Dig was led by Bechtel/Parsons Brinckerhoff, one of the largest and most experienced teams in infrastructure design and construction. Mitigation alone required 1,500 unanticipated, separate agreements.
The reported reasons for the cost escalation included inflation, the failure to assess unknown subsurface conditions, environmental and mitigation costs, and expanded scope. Estimates increased to $7.74 billion in 1992, to $10.4 billion in 1994, and, finally, $14.8 billion in 2007-more than five times the original estimate. Its initial estimated cost was $2.56 billion. The Big Dig is also famous for cost increases. Its list of engineering firsts include the deepest underwater connection and the largest slurry-wall application in North America, unprecedented ground freezing, extensive deep-soil mixing programs to stabilize Boston’s soils, the world’s widest cable-stayed bridge, and the largest tunnel-ventilation system in the world. Larger than the Panama Canal, the Hoover Dam, and the Alaska Pipeline projects, it was built through the heart of one of the nation’s oldest cities. Zakim Bunker Hill Bridge, part of the Big Dig project in Boston, is the widest cable-stayed bridge in the world.
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