Construction Engineering

US-95 Sandpoint North/South Byway

Location: Sandpoint, Idaho

DEA’s construction engineering services group was retained by the Idaho Transportation Department (ITD) under a staff augmentation contract to provide construction engineering, environmental compliance, and monitoring services for this landmark, $100 million byway project, which involved considerable bridge and structures work. ITD constructed 2.1 miles of new alignment connecting US-95 directly to State Highway 200, bypassing the downtown area of Sandpoint. The purpose of the byway was to relieve downtown streets of heavy truck traffic by building an alternate route on US-95 at the eastern edge of Sandpoint. The idea of constructing a heavy truck route around downtown Sandpoint had been discussed for more than 50 years, beginning during the Eisenhower administration, but controversy and debate among supporters of various concepts and their opponents had prevented anything being done.

In 1990, ITD began to consider a north/south alternative route on US-95, and the Sand Creek Byway became a segment of this alternative route project. Due to regulations to protect wildlife and environmental resources, construction was constrained to windows of time during which impact was minimal; every day of construction was affected by an environmental restriction. Additionally, the project accommodated a BNSF railroad line that required extensive historical and archeological excavation before construction. An award-winning community involvement effort helped to address citizens' concerns before work began on the byway. Construction work included removing 70,000 truckloads of excavated material, pouring 7,000 cubic meters of concrete, installing 455 miles of wick drains and 9 miles of piling, adding 77,250 cubic yards of fill in Sand Creek to construct the shoreline extension and pedestrian path, and constructing 65 retaining walls in 20 different locations. DEA’s construction manager coordinated project efforts directly with the ITD District 1 Residency in Sandpoint to provide a unified approach to construction oversight.