Here’s what you need to know about the closures of commuter trains and the Blue Line starting this weekend

The MBTA advised commuters to allow extra travel time through the end of April as closures double on parts of the Blue Line and the Newburyport/Rockport commuter rail.

The section of the Blue Line from Maverick in East Boston to Wonderland in Revere was closed Wednesday and was replaced by shuttle service.

The travel disruptions overlap with the suspension of service that began Friday on the Newburyport/Rockport commuter rail line between North Station and Swampscott.

Starting Monday, Blue Line trains will resume via Maverick, but service between the airport and Wonderland will be replaced by shuttle buses.

From Saturday, shuttle buses will also replace service on the Haverhill commuter line between Reading and Oak Grove.

The transit agency said this current round of reduced services will continue until April 28.

“During these closures, we will address 16 speed restrictions in the corridor as part of the route improvement plan. We will be carrying out additional work at each of the affected stations, including lighting repairs, painting and deep cleaning,” transit officials wrote in an update on their website Thursday.

Transit Ambassadors and other MBTA employees will be available to help riders adjust to the changes. Commuters are also encouraged to take advantage of nearly 500 free Bluebikes throughout the Greater Boston area thanks to a partnership between Boston and Blue Cross Blue Shield of Massachusetts.

“We are proud to help expand accessible and sustainable transportation options throughout Greater Boston,” said Jeff Bellows, vice president of corporate citizenship and public affairs at Blue Cross, in a Press release. “We believe this initiative will not only provide relief to commuters during MBTA closures, but also introduce new riders to the many benefits of the Bluebikes program.”

The free bikes became available on Wednesday and will be valid until April 28. Each rider is limited to five trips for each MBTA stop. The promotion also takes place during the closure of the red line from May 1 to 8.

Summer ferry service to Lynn will begin after the April closures end.