Tobin Bridge work to snarl traffic beginning April 1

State officials are warning motorists and other commuters about maintenance and repair work starting April 1 on the Tobin Bridge between Charlestown and Chelsea.

The work—the first rehabilitation of the 79-year-old Mystic River span since the 1970s—joins other major bridge work around the Boston region.

The Tobin construction “will require lane closures and result in significant traffic impacts on the Tobin Bridge and Chelsea Curves section of Route 1,” according to the Massachusetts Department of Transportation. The agency is warning that travel times will increase on sections of Route 1 northbound and southbound for drivers and bus riders, particularly during peak hours.

The northbound lane closures will start April 1. Two of three travel lanes will be open during the day, and one will be open overnight. As for Route 1 in the Chelsea Curves, two of three north and southbound travel lanes will be open during the day starting in early May. One will be open overnight.

MassDOT has come up with alternatives to avoid the Tobin mess. Fares will be free on inbound SL3 Silver Line buses at the Chelsea, Bellingham Square, Box District, and Eastern Avenue stops. Additional Blue Line trains will also run to pick up any spillover

MassDOT, too, advises that commuters consider the Haverhill or Newburyport/Rockport commuter lines.

The agency plans to wrap work on the Tobin and the Chelsea Curves in 2021.