MDOT plans to finish diverging diamond interchange at Telegraph/8 Mile Rd. by late fall

Starting later this year, motorists on Telegraph Road will notice that as they pass beneath Eight Mile, they’ll be routed to the left side of the roadway before returning to the right side.

This layout is called a diverging diamond interchange. The Michigan Department of Transportation built a series of these interchanges underneath key points on Interstate 75 in Oakland County between 2015 and 2023. And now it’s constructing one on Telegraph (U.S. 24) at the border of Detroit and Southfield.

This $54 million project also involves replacing the pavement on Telegraph between just south of Grand River and just north of Eight Mile, said Bill Erben, the MDOT construction manager overseeing the project. The construction work began in February 2023 and is expected to end in the late fall.

Erben said the pavement on this section of Telegraph and in the Telegraph/Eight Mile interchange was “falling apart” and needed to be reconstructed. They also decided to update the interchange itself. The existing one has free-flowing ramps that allow motorists to get from Telegraph to Eight Mile or vice versa. But because the ramps are “so short,” he said, the driver must pause at a stop or yield sign at the end of the ramp before continuing onto the road.

“We could have just rebuilt the old interchange back to the old, outdated standard,” he said. “We had to upgrade it to a current design standard.”

The new layout, a diverging diamond interchange, is a kind of interchange that temporarily shifts traffic to the oppose side of the road before returning it to the right side. This allow motorists to make free-flowing left turns onto an interstate or main road. Traffic signals control the flow of traffic in these interchanges. Erben said diverging diamonds prevent people from turning left in front of traffic.

In Oakland County, the state built these kind of interchanges off I-75 at 12, 14 and 16 Mile roads. He said he isn’t aware of any diverging diamond interchanges in Metro Detroit that aren’t underneath interstates, so this appears to be the first one. Diane Cross, an MDOT spokesperson, said her agency can only speak to state roads since MDOT doesn’t control county or city roads.

MDOT is also replacing the pavement on Telegraph. The roadway in the interchange will be made of concrete, and Telegraph between Grand River and just south of Eight Mile will be made of asphalt. He said MDOT is about 90% done with installing the asphalt and nearly 50% done with the concrete.

Mario Gjolaj, one of the owners of Omega Coney Island on 8 Mile in Detroit, said people will be confused by the diverging diamond interchange at first, because it’s something they’re unfamiliar with.

“But as they use it, you know, they’ll conform to the design and they’ll obviously see it for what it’s supposed to be,” he said. He is familiar with the diverging diamond at Big Beaver Road and Interstate 75.

Gjolaj said there has been other construction work in his area over the last few years as well. He can’t wait for the projects to be done.

“Because they affect my ability to come and go, and the costumers that I serve are affected by it also,” he added. He said he’s had fewer customers than normal because of the construction.

However, he said Telegraph was “horrible” in the few years leading up to the construction project. He noted that it was choppy and had potholes.

“It’s about time they repaired it,” he said.

asnabes@detroitnews.com