Mt. Elliott over I-94 Bridge Replacement

Bridge Replacement Design Plays Integral Role in Planned Highway Modernization Project

In conjunction with the multiphase, multiyear Michigan Department of Transportation (MDOT) I-94 reconstruction project to modernize the urbanized freeway segment through the heart of midtown Detroit, MDOT partnered with OHM Advisors to design the replacement of the Mt. Elliott bridge. MDOT desired to replace the four-span structure over I-94, which carried three lanes of traffic in each direction with sidewalks on each side, with a three-span structure carrying four lanes of traffic and including dedicated bike lanes and sidewalks on each side of the road.

Our team created a bridge design that had to accommodate the existing configuration of I-94 at Mt. Elliott as well as its proposed future reconfiguration. The future reconfiguration involves a shift in the freeway’s geometric alignment by over 100 feet to the north and a significant underground water utility impact requiring complex alternative design solutions. It also involves a road widening to include a fourth freeway traffic lane in each direction along with reconfigured interchanges, service drives and local roadways.

To create this challenging bridge design, our team relied on and collaborated with OHM Advisors roadway engineers who created all of the road design and approach design for the new Mt. Elliott bridge. Our multidisciplinary experts worked closely with MDOT, and with the Detroit Water and Sewerage Department (DWSD) and Great Lakes Water Authority (GLWA)—and during the design phase, we worked from a dedicated MDOT project office to streamline collaboration between all parties and consult on aesthetic treatments and accelerated bridge construction (ABC) concepts.

Rather than focus only on the bridge impacts, our team initiated underground water utility modifications that will be needed for the future I-94 roadway reconfiguration, which resulted in a study of options for water mains crossing under I-94 and in the adjacent service drives. The effort ultimately determined a path forward for mitigating concerns that included selective abandonment and rerouting of transmission lines. This work helped to eliminate conflicts while also helping to lay out a more efficient water supply network for future generations.

Project highlights: bridge design, roadway design and utility coordination