Funded by the City of Charleston, Charleston County, South Carolina Department of Transportation, and the Federal Highway Administration, this design-build project will be divided into five segments spanning from West Ashley to the east end of the project limits at Lockwood Drive. A key feature of the proposed design is a steel V-shaped pylon. Its outward-leaning stay cable plane will significantly reduce the risk of ice on the cables falling onto the pedestrian path.
Currently, commuters traveling on U.S. Highway 17 between West Ashley and Downtown Charleston must cross the Ashley River on two parallel bridges with narrow sidewalks. More than 63,000 cars cross these shared-use bridges daily. The high traffic volume resulted in more than 100 bike- and pedestrian-related crashes between 2014 and 2019 — necessitating comprehensive multi-modal transportation options.
To enhance the connectivity between Downtown Charleston and West Ashley, Superior and its design partner, Johnson, Mirmiran & Thompson, Inc. (JMT), developed a preliminary design for the pedestrian bridge that will mirror the functionality of the existing adjacent highway bridge. Their decision to construct the west and east approaches as boardwalk structures will enable the team to avoid delays from relocating existing Dominion Energy power lines and accommodate future planned greenway beneath the pedestrian bridge.
“This project presents some unique challenges, including performing work near high-voltage underground power cables and meeting environmental requirements specific to native marshlands,” said Superior Construction’s Carolinas Division Manager, Richard Kirkman. “We’ve devised some innovative technical concepts alongside our design partners to resolve each issue and fulfill the city’s need for safe, pedestrian-friendly transportation options.”
The team will construct the swing span bridge in the open position to minimize marine traffic impacts. The scope of work also includes new movable bridge operations with CCTV monitors, a touchscreen display, and discrete pushbuttons for the gates. Additionally, they will provide a trailhead with benches, water stations, and bike repair stations.
Construction is estimated to begin in April 2024, with expected completion in early 2027.