FALMOUTH, Maine (AP) Passenger rail service between Boston and Brunswick, Maine, is expected to expand by the end of this year with the completion of a critical rail project.

Amtrak’s Downeaster expects to make five round trips per day on its entire line as soon as it finishes the $9.4 million construction of a secondary passing rail line in Falmouth and Cumberland. The Portland Press Herald reports siding would allow service to flow better.

Northern New England Passenger Rail Authority Executive Director Patricia Quinn says Royal Junction Siding has been planned at least since the Downeaster’s expansion to Brunswick six years ago.

Officials say the Downeaster line is popular in Brunswick and nearby communities that don’t have a public transit link to Portland and Boston.