PORTLAND — Operators of the Amtrak Downeaster have decided to keep the train station at Thompson’s Point.

The decision comes as a group of stakeholders are working to move a nearby business that could pave the way for an improved transportation center for rail, buses and vehicles.

The Northern New England Passenger Rail Authority said this week the Portland Transportation Center at Thompson’s Point presents the best opportunity to keep operating costs low, find federal funding for upgrades, and foster economic development – provided certain improvements are made.

Those upgrades include build a multi-million dollar “Y” track behind Mercy Hospital’s Fore River campus to accommodate northbound trains to Brunswick.

NNEPRA began studying options for a new train station earlier this year in anticipation of expanded service to Brunswick, which is expected to begin operating next fall.

Shortly after announcing its evaluation of other potential train sites, developers unveiled a $100 million mixed-use development at Thompson’s Point. They cited its proximity to the combined train-bus station as a way for people to access conventions, concerts and Maine Red Claws basketball games without using vehicles.

An evaluation group with representatives from NNEPRA, the Maine Department of Transportation, the city, Concord Coach Lines and the Thompson’s Point development team, among others, evaluated other potential sites.

Alternatives were West Commercial Street, the former Union Station area on St. John Street, the Casco Bay Ferry terminal, the downtown business district and an area near Maine Medical Center. But only the West Commercial Street and Union Station locations were deemed feasible.

Executive Director Patricia Quinn said the proposed development was a major factor in NNEPRA’s decision to stay put. Not only will it give train riders a destination, but the city’s plans to offer a shuttle service to the waterfront will make it easier for riders to get into the Old Port.

“Thompson’s Point offers us the best opportunity to build a world-class intermodal facility,” Quinn said, with the convenience of ample parking, interstate bus service and shared operating costs (with Concord Coach Lines).

The shuttle service is expected to be funded through a Transit Tax Increment Financing District, which will funnel new tax dollars from the development to expansion and operating costs of public transportation.

Key to making the Thompson’s Point location work for the expanded service, however, is the installation of a rail “Y” behind Mercy Hospital’s Fore River campus.

The roughly $9 million upgrade will allow the Downeaster to pull out of the station and continue northbound to Brunswick without having to travel about a mile south before reversing direction. That process would add about 10 minutes to the northbound trip and complicate scheduling, Quinn said.

Councilor Kevin Donoghue, the Transportation Committee chairman, said the city is offering a resolution of support of NNEPRA’s efforts to receive grant funding for the project.

Donoghue also said the committee discussed expanding the transit TIF at Thompson’s Point to fund additional transit to link the point with downtown.

Quinn said the authority is seeking upwards of $20 million in U.S. Department of Transportation grants for the “Y” and other rail upgrades. The application deadline application is Oct. 31, she said, and NNEPRA should hear back by spring.

Meanwhile, the prospective developers of the Forefront at Thompson’s Point and city officials are still working on an effort to move Suburban Propane, which could lead to a new rail-side train-bus station and parking garage.

Quinn’s presentation to the Transportation Committee included a slide of two concept renderings of stations. One is a large brick structure with a parking garage and a skywalk over the train tracks. The other is a more modest, less-detailed sketch.

Economic Development Director Greg Mitchell said the drawings are “a vision of what could be built with public-private sector cooperation and joint funding.”

Quinn said if the new station doesn’t work out, then improvements could be made at the current station. The report highlights structured parking opportunities and space for an additional train platform.

“I’m pleased where we came down,” she said. “If everybody continues to work together, we can really build a great facility there. It’s going to take some time … some resources … (and) a lot of cooperation. But I think it has a lot of potential.”

Randy Billings can be reached at 781-3661 ext. 100 or rbillings@theforecatser.net. Follow him on Twitter: @randybillings