The U.S. Army Corps of Engineers says the Bourne Bridge will be down to two lanes as repair work expected to last into late May begins.
Workers starting Monday will be replacing damaged roadway joints on the bridge that crosses the Cape Cod Canal.
The bridge will have one, wider 12-foot lane instead of two lanes in each direction.
The Army Corps says the contractor will be working around the clock, seven days a week and lane restrictions will be in place at all times.
The work also includes repair of deteriorated steel and concrete, patching of damaged pavement surfaces, and replacement of waterproof membranes. Bridge lighting and drainage systems will undergo maintenance work.