Motorists in Chatham will have to stay off the Parry Bridge for the first week of January.
The bridge on Keil Dr. will be closed for five days for repairs.
Director of Engineering Adam Sullo says the latching mechanism that connects the two centre spans needs to be replaced.
"What's been happening over the entire life of that bridge is that, that area has been wearing because it's basically steel-on-steel," says Sullo. "The wear has opened a bit larger of a gap which has caused more movement."
All lanes on the bridge had recently opened in October after months of construction. Sullo says they were monitoring the mechanism during the last three months of construction.
"We actually had calipers that were monitoring the movement," he says. "We were wanting to see how much movement was happening, we were looking very closely at that casting."
Rather than proceed with a quick fix, Sullo says they want something that will last.
"We didn't want to be back in five years, trying to do another short-term repair on this," says Sullo. "We wanted to replace it and have it last the remainder of the life of the bridge."
Sullo adds a new casting is being manufactured at this time to prepare for the replacement.
The bridge will be closed from January 3 to January 7, 2017.
-With files from Matt Weverink
