I-95 over Lake Marion Bridge Replacement Design-Build

RK&K is serving as Lead Designer for this complex design-build project to replace and modernize four aging I-95 bridges spanning Lake Marion in Clarendon and Orangeburg Counties, South Carolina. The existing bridges are in deteriorated condition, with narrow shoulders that limit safe emergency pull-offs and require lane closures for routine maintenance. Because this section of I-95 is a critical freight corridor and hurricane evacuation route, maintaining traffic throughout construction is essential. Full detours were not feasible, as the nearest alternate crossing is approximately 20 miles away.

As Lead Designer for the Balfour Beatty/McLean Joint Venture design-build team, RK&K is providing comprehensive engineering and design services for the replacement bridges and roadway approaches. The firm’s responsibilities include structural and seismic engineering, roadway design, maintenance of traffic, hydraulics, geotechnical engineering, and other disciplines required to meet SCDOT criteria. In close collaboration with the contractor team, RK&K is also developing construction phasing and sequencing plans that allow traffic to be maintained safely and efficiently throughout the project.

The project includes a new 4,500-foot-long mainline bridge carrying I-95 across Lake Marion with two 12-foot travel lanes in each direction, 10- to 12-foot shoulders, and capacity for future widening. Additional features include an 8-foot utility corridor for a future water line and a 14-foot-wide, barrier-separated shared-use path to improve pedestrian and bicycle connectivity. A 360-foot-long relief bridge north of the main crossing will convey overflow waters beneath the interstate, while roadway approach improvements and removal of the existing bridges complete the project scope.

Once complete, the project will deliver a safer and more resilient crossing that improves freight movement, supports emergency response efforts, and ensures the long-term reliability of this vital I-95 corridor.