AETNA TOWNSHIP, Mich. (WOOD) — Road construction crews Sunday undertook the first ever bridge slide project in Michigan.
Crews are replacing the US-131 bridges over 3 Mile Road in Mecosta County’s Aetna Township, northwest of Morley. Sunday, crews replaced the northbound bridge using slide-in bridge construction.
In the new method, workers build the new bridge a few feet from where it will stand permanently and then knock down the old bridge.
“You build (the new bridge) on temporary lateral skids and then slide the new bridge in place,” Michigan Department of Transportation spokesman John Richard explained.
A lubricant, often dish soap, is used the slide the bridge into place. It’s an extremely slow, painstaking process.
“You only can move it a couple inches at a time. They’ve got to make sure it’s completely even,” Richard said.
The northbound US-131 slide, which moved a 1.5 million-pound bridge, started around noon Sunday and was expected to take around 10 hours.
While the old way of putting up the new bridge would have rerouted traffic in the area for four or five months, MDOT says, the slide is expected to disrupt traffic for only five days as crews work on bridge approaches.
Before northbound US-131 reopens — which should be on Thursday — drivers are asked to detour off the northbound lanes at Jefferson Road (Exit 125), to east to Northland Drive, then go north to 8 Mile Road, and then west to get back on the highway.
Sunday’s was the first bridge slide to happen in Michigan, but it has been done in other states. MDOT liked the idea — it’s safer, smoother and smarter, they say.
“At $3.50 a gallon or whatever gas costs, the savings is in the millions for motorists and, of course, the time saved is immeasurable,” Richard said.
MDOT says the US-131 slide-in bridge construction will save drivers $2.23 million.
The southbound bridge will be replaced later this month, MDOT says. In all, the bridge replacements over 3 Mile Road cost $4.2 million.
Crews will perform another bridge slide operation soon when they replace the M-50/Alden Nash bridge over I-96 near Lowell in Kent County. There, the new bridge is already under construction.
“Where you can, this will become a new standard,” Richard said.
>>On YouTube: MDOT rendering of how slide-in bridge construction works