The $224 million I-64 Widening and Improvement Project upgraded a 4-mile section of I-64 in Putnam County, West Virginia, between the U.S. 35 interchange to the west and the Nitro interchange to the east. The project provided six lanes for traffic and added a new major river crossing that features the longest-span steel plate girder bridge in the United States.

HDR served as the engineer for the contractor and was responsible for permitting, stakeholder coordination and complete design services for the roadway and bridges. We also designed the traffic control and staging of the structures to maintain four lanes of interstate traffic throughout construction.

Delivered via design-build, the project:

• Constructed a new second bridge over the Kanawha River for westbound I-64 traffic (parallel to the existing bridge), and then replaced the superstructure of the existing Donald M. Legg Memorial Bridge to carry eastbound I-64 traffic
• Widened 4 miles of interstate from four to six lanes
• Reconstructed the St. Albans interchange to include flyover ramps using curved steel plate girder structures, making it a new tri-level interchange, eliminating a stop sign and crossing traffic
• Replaced four other steel plate girder structures along the mainline
• Provided ongoing communication to the public, including maintaining the project website
• Required a robust transportation management plan to evaluate temporary conditions and detours

New River Crossing

Previous two-way traffic on I-64 was carried on a truss bridge, the Donald M. Legg Memorial Bridge. This project added a parallel long-span plate girder structure that temporarily carried two-way traffic, allowing the existing truss bridge to have its superstructure replaced as a plate girder bridge. In final configuration, eastbound and westbound traffic each has its own dedicated long-span plate girder structure — westbound on the new bridge and eastbound on the refurbished bridge. The new river bridges have been designed for a 100-year service life.

The new Kanawha River Bridge is a dual three-span steel plate girder bridge with a 562-foot main span and two side spans (380- and 390-feet in length). Each of the parallel structures is 65-feet 2-inches wide to accommodate six lanes of mainline traffic along with two lanes for ramp traffic. The piers of the existing bridge were reused, so their placement set the span length for both bridges, defined by the navigation channel of the Kanawha River.

The chosen design of a plate girder bridge offered an efficient structure type for the bridge span, ideal for design-build delivery, and ideal for the owner because of more straightforward details to inspect and maintain during the life of the structure. We performed higher-level analyses on the plate girder design due to the record-setting length including analyses for wind stability, thermal gradient and dynamic live loads. The design used bottom lateral bracing to increase aeroelastic stability during and after construction, which allowed the design-build team to take advantage of bottom lateral bracing for increased girder bending resistance in 3D analysis.

The I-64 Kanawha River Bridge sets the record as the longest-span steel plate girder bridge in the United States, with its 562-foot main span. It is the second record-setting bridge that HDR has designed in West Virginia in the past decade following the Shenandoah River Bridge Delta Frame, which was the largest of its type as well. Our history of designing bridges for the West Virginia dates back over 75 years.

The project was substantially completed in 2024.