Wilmington Bypass Design

Location Wilmington, North Carolina

Owner North Carolina Department of Transportation

Client North Carolina Department of Transportation

  • Controlled-Access Highway (Non-Interstate) Design
  • Cloverleaf Interchange Design
  • Diamond Interchange Design
  • Stormwater/Pavement Drainage Design
  • Wetland Mitigation
  • Construction Phasing Plan Development
  • Right of Way Plan Development
  • Final Plans, Specifications, and Estimates (PS&E)
  • Constructability Review

The North Carolina Department of Transportation (NCDOT) is extending US 17 on new location to form a bypass around the Wilmington, from NC 87 to I-40. Two of the bypass’s three sections have been constructed. This project involves the final 8-mile section from US 74-76 to US 421, with a crossing over the Cape Fear River.

As prime consultant, Lochner advanced NCDOT’s preliminary design to right-of-way plans, final plans, and construction documentation for the 8-mile, four-lane divided freeway with a 46-foot-wide divided median. Lochner liaised extensively with NCDOT to incorporate the Department’s design of dual high-rise structures, spanning 1.8 miles over the Cape Fear River, Toomers Creek, and adjoining wetlands, with Lochner performing all required roadway design for the large water crossing. Lochner also performed interchange design for two partial diamond and two semi-directional interchanges, which required coordination with the design-build team of an adjacent project. The design of two interchanges was constrained by railroad right of way, requiring the entire realignment of one interchange and the relocation of on- and off-ramps at the other.

The entire project was situated in the Cape Fear River floodplain and a large wetland area. Lochner’s design therefore had to avoid excavation work and address several challenges in the development of an effective drainage solution. Lochner also coordinated with the developer of an adjacent parcel of land to incorporate the construction of the developer’s noise wall into the project design.


2018 ENR Southeast Regional Best Project Award, Highways/Bridges

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