The most direct route from Charlotte in Eaton County to Marshall in Calhoun County is I-69. Although direct, the 20-plus-mile stretch of interstate was a poor ride for commuters.
MDOT was spending lots of money to patch the road. “The very rough pavement was notorious for buckling during the warm summer months,” says Mike Meyer, MDOT Project Manager for the I-69 project. Multiple times a year MDOT was out on the road trying to keep it together.
It was clear to MDOT that the interstate needed to be rebuilt.
“The rebuild was going to be built over eight years and four different segments,” Meyer says. “However, the Rebuild Michigan program gave us a boost in funding and turned this into one megaproject.”
Meyer and the team were determined to get the project done faster, so it would be less of a burden on commuters. The project schedule was whittled down to three construction seasons. The project began in September 2020 and is scheduled to be complete in November 2023.
How was MDOT able to speed up the schedule? Turning it into one megaproject certainly helped. However, a more significant reason is the decision to choose design-build.
“Design-build expedited the construction schedule as we're able to compress the design element and overlap it with the construction piece,” says Meyer. “It also creates less impacts to the motoring public.”
Currently, the project is on schedule. Meyer credits favorable weather and a skilled dirt work subcontractor, “They've been phenomenal about keeping things moving forward.”
The contract amount for the project was $210 million. The state put up $102 million while the federal government put up the remainder. Currently, the project is slightly over budget, but still within the upper-level projections.
A costly issue the team ran into occurred as they were maintaining traffic in one area part of the road was falling apart. So, they had to temporarily patch it to maintain the traffic flow. In addition, the team ran into even more unsuitable soils than was planned, which meant they cut out beyond what they were expecting.
To keep the budget within range moving forward, Meyer says, “The key is not deviating from the scope of the contract and going down a rabbit hole to chase things down.”
Along with reconstructing the road, MDOT is replacing all the interchanges and ramps. There's also another 2-mile stretch that MDOT is patching. They are going all the way down to the subgrade. Once there, they will construct a new drainage system to keep the water out from underneath the road. The team expects that this will help the road exceed the service life that is typically projected. To reach this goal, there have been days where MDOT has put down 3,000 to 4,000 tons of asphalt.
In addition to rebuilding the road, the project includes work on the interchanges. There are six interchanges included within the project limits. Finally, MDOT is doing preventive maintenance on 26 bridges along the corridor. One bridge – 15 Mile Road bridge, which runs over I-94 and is about four-tenths of a mile long – is being completely reconstructed.
“Going down to the subgrade is a challenge because there's lots of pavement to remove before we can reconstruct the grade,” says Meyer.
The bottom layer is a 9-inch layer of reinforced concrete. Above that was a 1-inch asphalt separator. Completing this road sandwich is another 8-inch to 12-inch layer of non-reinforced concrete.
The team had to determine what to do with all the pavement that they were removing. Rather than simply hauling it away, they found a practical environmentally friendly use. “We are taking it off, crushing it, and recycling it,” says Meyer. The recycled road is being used as an aggregate base for the new road.
The new pavement section will be 10.5 inches of hot mix asphalt pavement on top of 6 inches of the recycled aggerate base over 18 inches of new sand subbase.
Meyer cites an example. They suggested combining some ramp interchange closures that reduced conflict points of traffic. This expedited the work, reduced the conflicts between the motoring public and the work zone, and created a safer work zone for all.
Thanks to Rebuilding Michigan, the public will enjoy a smoother, faster ride on an important route for commuter, commercial, and tourism traffic. Plus, it's being completed cheaper and quicker than original projections. That’s a win-win.