CUMBERLAND — Roads around railroad crossings here and in Falmouth will be closed on Wednesdays over the next few weeks, requiring all traffic to find alternate routes.

As part of its $9.4 million Royal Junction siding project, the Northern New England Passenger Rail Authority is building a 4-mile siding that will allow passenger and freight trains to pass each other.

The siding will run next to the Pan Am Freight Mainline, from about 1,000 feet east of Field Road in Falmouth to just east of Royal Junction, northeast of Greely Road in Cumberland.

NNEPRA administers Amtrak Downeaster passenger rail service, which runs between Brunswick and Boston. Log onto nnepra.com/projects/royal-junction-siding for more information on the siding project. Updates will also be posted at cumberlandmaine.com/rrcrossings.

Cumberland roads that will be closed from 8 a.m.-8 p.m. are Tuttle Road, Aug. 1; Route 9 (Longwoods Road), Aug. 8; Greely Road, Aug. 15, and Muirfield Road, Aug. 29.

Woodville Road in Falmouth will be closed Aug. 22.

“The first part of this is getting these crossings in; they’re big sections,” Cumberland Town Manager Bill Shane said July 26. “… The second part will happen probably in mid-to-late September, where they’ll come in and finish the road surface.”

A temporary surface will be used in the meantime, Shane added.

“Once the tracks are connected, then they know if there’s any additional compaction they need or any additional adjustment,” he said, adding that final paving will occur when those tweaks are complete.

Signs will be posted a week in advance of each closure to warn drivers, bicyclists and pedestrians to seek alternate routes.

Pan Am track crews since late April have partly assembled about a third of the approximately 21,000 track feet planned for the project, NNEPRA reported.

“Royal Junction Siding will provide additional track capacity necessary to enable more frequent and efficient daily operation of Downeaster trains and freight trains between Brunswick and Boston,” the organization said in an online project description. “This passing siding removes a key bottleneck for the Downeaster that will create more options for the traveling public while improving the financial and operational efficiency of the service.”

Alex Lear can be reached at 781-3661 ext. 113 or alear@theforecaster.net. Follow him on Twitter: @learics.

This railroad crossing on Greely Road in Cumberland is one of five in the town and neighboring Falmouth that will be closed to all traffic the next few Wednesday while a 4-mile siding is installed.