Modernize I-75: Segment 3

Project Overview

Segment 3 of the I-75 Modernization Project includes the reconstruction and widening of a 5.5-mile segment of I-75 from M-102 (8 Mile Road) to south of M-59 in Metro Detroit, Michigan, consisting of complete pavement reconstruction, modernization of the freeway, ITS upgrades, and replacement of 28 bridges. Additionally, the project includes approximately four miles of 14.5-foot diameter stormwater tunnel to separate freeway water from the local combined sewer system to mitigate future flooding concerns. The project is delivered through a 30-year design/build/finance/maintain contract that consolidates what would have been five (5) construction contracts into one and accelerates the project completion by over 10 years.

Project Scope

NTH was engaged by AECOM to assist primarily in the investigation, design, and construction inspection of the large-diameter stormwater tunnel portion of the project, based on NTH’s decades of experience in soft-ground tunneling in the project area. NTH’s experience and responsiveness during design and construction helped to keep the project on track and on schedule, even when faced with challenging underground conditions. When needed, NTH stepped in to take on additional roles for laboratory testing, QA/QC, special inspections, and construction materials testing for the roadway and bridge portions of the project.

Client Benefit

NTH’s unique combination of local resources and national tunnel and underground construction expertise helped maintain project timelines, even when faced with challenging subsurface conditions.