Lane restrictions will be in place on Interstate 83's John Harris Memorial Bridge, also called the South Bridge, across the Susquehanna River in Harrisburg until Friday morning.
Traffic could be limited to a single lane in one or both directions on I-83 as crews work each night from 9 p.m. to 5 a.m., according to the Pennsylvania Department of Transportation.
Crews are making repairs to the bridge joints and cleaning the drainage facilities on the bridge.
The John Harris Memorial Bridge is the most heavily traveled bridge in the region, with an average traffic volume of 125,000 vehicles a day, PennDOT said. Work is being conducted at night, when the traffic volume is lowest.