Marquette County, MI

US-41 and M-28 Pedestrian Tunnel, Chocolay Township


The US-41/M-28 Access Management Plan sought to improve access along the corridor. One such improvement included the construction of a pedestrian tunnel under US-41/M-28 to replace an existing overpass in Chocolay Township. The pedestrian tunnel links the pedestrian/bicycle pathway on the east side of the highway to a new non-motorized pathway on the west. SGH assisted Upper Peninsula Concrete Pipe Company (UPCPC) with the design of precast concrete culvert that would create the tunnel under the existing highway.

SGH helped UPCPC tackle challenges related to the configuration of the pedestrian tunnel that comprises a skewed end section terminating the tunnel at a retaining wall directly under the roadway. Recognizing the benefits of a precast alternative, the project team selected a precast concrete structure for the tunnel and a combination of precast and cast-in-place elements for the termination under the roadway. Our work to support UPCPC’s production efforts included the following:

  • Design of the basic precast reinforced concrete culverts sections in accordance with American Association of State Highway and Transportation Officials (AASHTO) and Michigan Department of Transportation (MDOT) standards
  • Determination of the loads on the culverts sections, including all Michigan legal truck loads and trucks carrying oversized loads
  • Generation of truck load ratings for the culvert for submittal to MDOT
  • Design and integration of precast concrete elements and cast-in-place elements to accommodate the required geometry and minimize the amount of concrete cast in the field

Project Summary



Completion Date
New Construction
Advanced Analysis
Infrastructure & Transportation
Upper Peninsula Concrete Pipe Company
Specialized Capabilities
Buried Infrastructure