The bridge connecting Route 201 between Winslow and Waterville is now closed for about six months so crews can finish work on a replacement.
MaineDOT says 14,000 cars use the Ticonic Bridge on a daily basis and parts of the structure are more than century old.
Following the six-month-long closure, eastbound vehicle traffic will be allowed back on the bridge, but westbound vehicle traffic will remain prohibited from the bridge for between 12 and 18 months while construction continues.
When the bridge reopens to eastbound vehicle traffic, MaineDOT will also reopen the bridge to pedestrian traffic, using the new sidewalk on the upstream side of the bridge.
On-site work for the Ticonic Bridge replacement project began in December 2022. The structure is being replaced on the existing alignment.
According to MaineDOT, the new bridge will be a two-span structure, made of corrosion-resistant steel girders and a concrete deck. A single concrete pier will be built in the river to support the new bridge, which will reduce the likelihood of ice jams, the agency says.
MaineDOT says portions of the old bridge are more than 100 years old and at the end of their useful life. The new bridge will carry five lanes of traffic (similar to the existing bridge), feature widened shoulders, and include sidewalks on both sides. On-site construction is scheduled to be completed by the end of May 2027.
The contractor on the project is Cianbro of Pittsfield. The contract amount is $52.8 million.