How MDOT inspects bridges across Michigan
MDOT said most of the bridges in the U.P. are “fair” and drivers should not be concerned.
GWINN, Mich. (WLUC) - From above and below, the M-35 bridge in Marquette County just west of Gwinn is considered to be in “fair” condition.
It carries nearly 5,000 vehicles a day over the Escanaba River and regular inspections keep track of its conditions.
“We need to figure out when we need to fix them because we have limited budget and we need to properly utilize our dollars to keep our bridges in safe condition,” said MDOT Bridge Engineer Jordy Maloney.
He said all bridges are to be inspected at least once every 24 months.
The process begins at the top, checking railings, any approach slabs and joints, plus looking for cracks or potholes in the pavement – which could pose a threat to the lifespan of the bridge.
“There’s steel rebar inside the concrete deck and then a lot of our bridges have steal superstructure which is the beams or the girder. If we can seal up the surface, we can kind of keep the salt and water from getting to the steal,” Maloney said.
Underneath, engineers examine the beams and bearings, paint chipping and rust, abutments, and piers.
“From there, we’ll actually look at the stream bed itself to make sure that we don’t have any scour issues or stream degradation that could cause any instability in our structure as a whole,” said Maloney.
Each bridge is rated from zero to nine, with a zero meaning a bridge should close.
MDOT says most of the bridges in the U.P. are “fair” and drivers should not be concerned.
93 percent of state trunkline bridges are good or fair and 7 percent are poor.
Local bridges are 86 percent good or fair with 14 percent considered poor.
You can find more information on Michigan bridge conditions here.
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