A bridge that carries Interstate 84 westbound over the Housatonic River will close for more than a year starting Friday. Median crossings will direct westbound traffic onto the current eastbound side of the Rochambeau Bridge, allowing all four lanes of highway traffic to stay open while the bridge is replaced. The crossings will be connected to I-84 westbound overnight Thursday into Friday, going live before 5 a.m. The crossovers will be in place for about two years while the westbound bridge is partially demolished and reconstructed. Little impact on traffic is expected, but drivers may notice a slight shift while crossing the median. The project began June 15 and will be completed by December 2023. Construction will involve using work trestles and barges. The state DOT’s contract for the work was awarded to Middlesex Corporation for $52 million.