A rendering shows the proposed 12 Mile Road interchange project at Interstate 75, which will convert the interchange from a partial cloverleaf to a diverging diamond interchange.

A rendering shows the proposed 12 Mile Road interchange project at Interstate 75, which will convert the interchange from a partial cloverleaf to a diverging diamond interchange.

Rendering provided by the Michigan Department of Transportation


I-75 project to redo 12 Mile Road interchange

By: Sarah Wojcik | C&G Newspapers | Published June 23, 2021

OAKLAND COUNTY — Beginning in March 2022, the 12 Mile Road interchange at Interstate 75 will undergo a complete overhaul, part of Segment 3 of the Michigan Department of Transportation’s I-75 modernization project.

The current configuration of the interchange is known as a partial cloverleaf, which features loops in the northwest and southeast quadrants. The new design is known as a diverging diamond interchange, or DDI.

Sean Kelsh, project manager of the Oakland Corridor Project, said not only is the infrastructure of the 12 Mile interchange aging and in need of replacement like most of the corridor, but the interchange roadway geometry is also outdated.

“The length of the ramp isn’t sufficient to get up to the speed that we want, and especially for trucks to merge into the freeway, the traffic ramps are too short,” Kelsh said. “They were built back in the ’60s and ’70s. Standards were much different, and speed limits were different.”

DDIs have been used for approximately the last decade and allow more operational efficiency, Kelsh said. Other DDIs are located at University Drive and I-75, Big Beaver and I-75, and 14 Mile and I-75, which is still under construction.

“It has a small footprint and doesn’t require a lot of right of way,” he said.

The configuration reduces the number of conflict points, or areas where crashes are likely to occur, from 26 to 14, according to data from DDIs at University Drive and I-75 and Cascade Road and Interstate 96 in Grand Rapids.

“The funny thing with a DDI is, often, folks who haven’t driven them before will drive through it and won’t realize they’ve even driven through it because they do flow very nicely and they’re really easy to maneuver,” Kelsh said.

Other improvements planned as part of the interchange project include a new handicapped-accessible pedestrian bridge at Bellaire Avenue that is currently under construction, as well as carpool lots in the northwestern and southeast quadrants of the interchange to compliment the high-occupancy, or carpool, lane that will run through the length of the entire project.

Two sound walls are also proposed along residential areas — the first along the southbound exit ramp, and the second along the northbound exit ramp, which will be contingent on voter approval of nearby residents.

Lastly, crews will construct a box culvert under the southbound exit ramp to enhance the safety of an existing maintenance access point, in which authorized vehicles currently have to cross from one side of the ramp to the other without a signal.

“(The box culvert) could also accommodate a future path (proposed by) the city of Madison Heights,” Kelsh said.

Construction on the interchange will begin in 2022, with crews removing the existing interchange ramps and removing 12 Mile Road, which will be closed and detoured to through traffic with access to businesses at all times.

Kelsh said the detours are currently being determined with the Oakland County Road Commission and the cities of Madison Heights and Royal Oak.

David Nachman, CEO of Oakland Corridor Partners, said the 11 Mile Road bridge is set to be closed and demolished the weekend of July 10 and will reopen in November, in time for the 12 Mile interchange project.

“Gardenia (Avenue in Royal Oak) will be closed (during the interchange project), but it won’t be closed for the whole season,” Nachman said. “Gardenia certainly won’t be closed from March through November. It will be something less than that, probably three or four months.”

While the majority of construction will take place in 2022, work will halt from November to March for a seasonal shutdown and all lanes of the interchange will reopen. Construction will then resume in March and wrap up in late fall of 2023.

Kelsh added that night work would be minimized to only essential short-term work items, like bridge removal and bridge deck pours, and crews would monitor air quality and dust control with mitigation through regular watering.

Segment 1, a 3.1-mile portion of I-75 from north of Coolidge Highway to north of South Boulevard, is complete. Segment 2, an 8.6-mile portion from north of 13 Mile Road to north of Coolidge Highway, is almost complete. Segment 3, a 5.5-mile stretch from Eight Mile Road to north of 13 Mile Road, is set to conclude in the fall of 2023.

For more information, visit modernize75.com or call (586) 486-3626.