Project Details

Managing Joint Venture Partner
North Carolina Department of Transportation
$192 million
February 2006
Start Date
February 2010
Completion Date

Building the Washington Bypass

A Flatiron-managed joint venture is responsible for a 6.8 Highway 17 bypass around Washington and Chocowinity, North Carolina, including a three-mile bridge over the Pamlico-Tar River and environmentally sensitive wetlands.

To ensure minimal disturbance to the surrounding environment, Flatiron developed a variation of a top-down construction technique. The new patented Tilting Lead Gantry enabled the team to build the bridge in an assembly-line fashion. This efficient and eco-friendly process enabled the team to complete the project seven months ahead of schedule and within budget, performing more than 680,000 man-hours of work with minimized lost-time incidents.

In this span-by-span construction method, all bridge work was preformed from cantilevering, self-contained gantries, including driving the precast piles, building the bent caps, erecting the 120-foot-long precast girders and pouring the deck. The newly constructed permanent structure was then used for personnel access and material deliveries. The structures were constructed without temporary access trestles, thus significantly reducing environmental disturbances.

Patented, proprietary top-down construction technique to minimize footprint over wetlands

8 miles of four-lane highway through environmentally sensitive terrain

Two major interchanges and one three-mile long bridge

American Road and Transportation Builders Association
Globe Award Honorable Mention 2011
Associated General Contractors of America
Build America Award 2011
Federal Highway Administration
Environmental Excellence Award 2009
National Partnership for Highway Quality
National Achievement Award 2011
"This is a project we can take great pride in. Incredibly innovative techniques were used throughout the process of designing and constructing this structure, not only did these efforts save time and money they also set a standard of excellence for future projects in our state."
Gene Conti, Secretary of Transportation, North Carolina