Greater Portland Transit District officials are hoping to extend bus service to Cumberland, Freeport and Yarmouth by taking advantage of a federal grant program to reduce air pollution and traffic congestion.

The bus district, better known as Metro, presented a service-expansion proposal this week to officials from municipalities in the Portland area during a joint meeting.

Metro has not yet determined how many new routes would be added, or where they would go, spokeswoman Denise Beck said.

“The project’s in very early stages of development,” Beck said.

The most likely routes for expanded service would be along the Interstate 295/Route 1 corridor, she said, including a commuter route extending from Portland to Freeport.

Freeport Town Planner Donna Larson said town officials have been talking for years about a possible bus service to Portland, and that the Metro proposal is the closest it has come to being a reality.

“There is certainly support for looking into this and seeing what type of service could work for the town,” Larson said.

The plan is to apply for a federal Congestion Mitigation and Air Quality grant that would fund 80 percent of a two- to three-year pilot program for expanded service. The other 20 percent would come from local sources, Metro said.

The program’s total cost would depend on the number and extent of new bus routes, it said.

Metro has nine existing bus routes: Congress Street, Riverton, North Deering, Westbrook, Maine Mall, Washington Avenue, Falmouth, Peninsula Loop and a modified Peninsula Loop route during tourist season.

Metro has asked top administrators of participating communities to meet this month to develop up to three options for expanded bus service, and to explore possible scenarios in which the private sector would contribute funds.

The transit district presented a proposed time line to municipal leaders that would proceed as follows:

October: Develop service options and explore private-sector participation.

December: Present service options to municipal councils and develop a consensus on the preferred option.

January: Submit a grant proposal to the Maine Department of Transportation, which oversees Maine’s allotment of the federal grant program.

If a grant is awarded, extended bus service would start in the summer of 2014.

The program would be evaluated for a two- to three-year period to determine whether it should be implemented permanently, Metro officials said.

J. Craig Anderson can be contacted at 207-719-6390 or:

canderson@pressherald.com

Twitter: @JCraigAnderson