Here’s what to know about the commuter rail and Blue Line closures starting this weekend

The MBTA advised commuters to plan for extra travel time through the end of April as closures double up on parts of the Blue Line and Newburyport/Rockport Commuter Rail.

The section of the Blue Line running from Maverick in East Boston to Wonderland in Revere shut down on Wednesday and was replaced by shuttle bus service.

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

Starting on Monday, Blue Line trains will resume through Maverick, but service between Airport and Wonderland will be replaced with shuttle buses.

Beginning Saturday, shuttles will also replace service on the Haverhill commuter line between Reading and Oak Grove.

The transit agency said this current round of reduced service will run through April 28.

“During these closures, we’ll address 16 speed restrictions in the corridor as part of the Track Improvement Plan. We’ll perform additional work at each of the impacted 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 navigate 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 contribute to the expansion of accessible and sustainable transportation options throughout Greater Boston,” Jeff Bellows, vice president of corporate citizenship and public affairs at Blue Cross, said in a press release. “We believe that this initiative will not only provide relief to commuters during the MBTA closures but also introduce new users to the numerous benefits of the Bluebikes program.”

The free bikes became available on Wednesday and run through April 28. Each rider is limited to five trips for each MBTA shutdown. The promotion also runs during a Red Line closure from May 1 through May 8. 

Summer ferry service to Lynn will begin after the April shutdowns wrap up.