second avenue bridge

Detroit's Second Avenue Bridge Wins NSBA Prize Bridge Award

The HDR-designed Second Avenue Bridge in Detroit, Michigan, has been named the 2024 Prize Bridge (Medium Span) by the American Institute of Steel Construction and the National Steel Bridge Alliance. 

The Second Avenue Bridge over I-94 is the first unbraced, network tied-arch bridge constructed on a skew in the U.S., and one of three finalists for the NSBA’s 2024 Bridge of the Year. An innovative accelerated bridge construction process allowed the bridge to be assembled nearby and moved into place using self-propelled modular transporters, or SPMT. The bridge opened to traffic in December 2022.

Both the network tied arch design and SPMT construction processes were firsts in Michigan. Michigan DOT is the bridge owner and Tetra Tech was the prime consultant on the project and provided abutment design, drafting and load rating services for the bridge. HDR was responsible for the design of the network tied arch span, structural analysis, construction sequence, design-phase contractor outreach and onsite construction observation.

“Our bridge design teams continually push the bounds of innovation to meet the needs of our clients and communities,” said HDR Bridges & Structures Director Manuel Carballo. “In this case, we had to span the future I-94 roadway and accommodate adjacent properties, including a historic Motown recording studio. This required HDR to design the 245-foot-long, unbraced network tied arch span at a skew of 18 degrees.”

The bridge's skewed layout fit the site, but it created hurdles for the design, fabrication and construction. None of the connections were square and each bridge component was unique. Those challenges were compounded by assembling the 5-million-pound bridge skeleton on temporary supports and moving it to the final location

The 2024 Bridge of the Year award will be announced during the World Steel Bridge Symposium March 20-22 in San Antonio, Texas. Recent honors for the bridge include being ranked number 4 in the Roads & Bridges Magazine annual list of Top 10 Bridges.