Shocked and disappointed: That's how Patricia Galloway, chair of the three-member expert review panel for Washington state's $2-billion Highway 99 bored-tunnel project, described the panel's scrapping by state lawmakers.

State legislators apparently perceived the panel as a legal risk and wanted to retain a clear distinction between the roles of the state and the contractor, avoiding any appearance that the state-named panel was providing recommendations to the contractor. Neither the Washington State Joint Transportation Committee, which appointed the panel, nor its coordinator would comment beyond confirming the panel's demise.

It remains a mystery as to who will pay for the project's added costs and delays. A key component of the project, the world's largest tunnel-boring machine, became stuck in December 2013, and part of it has been removed for repairs. The panel has said the extra costs could reach $293 million and that work is 18 months behind schedule. Speculation in Seattle has revolved around the likelihood of litigation if Seattle Tunnel Partners—comprised of Dragados USA, ACS Group of Spain and Tutor Perini Corp.—and owner Washington State Dept. of Transportation, prove unable to resolve differences. Seattle Tunnel Partners' design-build contract is valued at $1.35 billion.

WSDOT could not be reached for comment on the panel's disbanding or prospects for resolving possible disputes. Galloway, a former American Society of Civil Engineers president who spends 60% of her professional time as a mediator and arbitrator, says the panel does not in fact add legal exposure.

"This is not unique or unusual for a project at this stage to have disputes," she says. "This is the construction world. We think we could add extreme value based on our experience and knowledge on megaprojects worldwide that had bigger disputes and issues than they are having here."