Chestnut Street & Market Street Bridges

Benesch was retained to inspect, assess and rehabilitate or replace the structures on Market and Chestnut Streets. This challenging assignment required balancing the needs and desires of PennDOT, the City of Philadelphia, local businesses, three railroads (Amtrak, SEPTA, & CSX), multiple public & private agencies, universities, vehicular/bicycle/pedestrian commuters, and the local residents with respect to traffic, schedule and budget, all while extending the remaining useful life of the structures by at least 30 years.

The existing bridges on Market Street were originally constructed to connect the 30th Street Station Complex to Center City Philadelphia in the early 1930s. The historic multi-span open spandrel arch with masonry facade is listed on the National Register and was built integral with the SEPTA Subway Tunnel below the Schuylkill River. The river crossing along with the four-span steel structure over the Schuylkill River Trail, CSX railroad and abandoned railroad spans provide a vital multi-modal transportation link for the area. The existing Chestnut Street structures encompassed the elevated platforms around the historic 30th Street Post Office Building and the bridge network extending east on Chestnut Street over the Schuylkill River to 24th Street.

Because the project area has undergone a significant urban renaissance—including a 2.7M-square-foot tower poised as the city’s first “vertical neighborhood” and other nearby commercial structure renovations—extensive stakeholder coordination and construction staging were key to the project’s successful design.

The presence of three nearby railroads (SEPTA, CSX, and Amtrak—the latter including its third busiest rail hub in the nation, Philadelphia’s 30th Street Station) and several 100+-year-old structures presented additional challenges. Many of these structures are considered contributing elements to a National Register-listed historic district.