AETNA TOWNSHIP, Mich. (WOOD) — It took road construction crews about twice as long as anticipated to slide a new bridge in Mecosta County into place.
The Michigan Department of Transportation used the slide-in bridge construction method to replace the northbound US-131 bridge over 3 Mile Road, northwest of Morley.
The slide, which began on Sunday, was supposed to take about 10 hours. Instead, MDOT said Tuesday, it took crews about 23 hours to finish sliding the 1.5 million-pound bridge to its permanent spot.
In traditional bridge construction, crews knock down the old bridge and then put up the new one. Using slide-in bridge construction, the new bridge is built next to the old one, the old one is demolished, and the new one is slid into place. Dish soap is often used as the lubricant to move the bridge.
The bridge slide saves drivers time and money, MDOT says, by cutting down how long detours are in effect. In Mecosta County, drivers would have had to detour around the area for as long as five months if traditional construction had been used.
As it is, MDOT said Tuesday it was still on track to have the northbound US-131 bridge open to traffic on Thursday — even though the bridge slide took much longer than expected.
In the meantime, traffic is being rerouted off the highway at Jefferson Road (Exit 125), then east to Northland Drive, then north to 8 Mile Road, and then west back to the highway.
The southbound US-131 bridge over 3 Mile will be slid into place in mid-September, MDOT said Tuesday. In all, the bridge replacements will cost $4.2 million.
MDOT is also using the bridge slide method to replace the M-50/Alden Nash bridge over I-96 near Lowell in Kent County. Traffic in that area has already been affected, but the new bridge has not yet been slid.
That project will be a little different than the US-131 project because the bridge is much bigger, MDOT says. The M-50 bridge will be pushed into place, rather than pulled like the US-131 bridge.
MDOT says the bridge slide is expected to become the new norm for bridge replacement when space permits.