It might seem crazy that a private company says it wants to operate passenger train service in New Hampshire’s Merrimack River valley – an idea that has been fiercely debated for decades – by running on a different company’s tracks.

It’s not crazy at all: Just look east.

“The Downeaster,” said Louis Barker, railroad planner for the New Hampshire Department of Transportation, referring to Amtrak’s service from Boston to Brunswick, Maine, when asked if there was any precedent for such an idea. “That’s the same arrangement.”

A private Rhode Island startup called Boston Surface Railroad Company says it is on schedule to develop passenger service between Worcester, Mass., and Providence, R.I., by 2018. The parallels with Amtrak, a quasi-government nonprofit, aren’t exact, but they do demonstrate that the idea is feasible.

Boston Surface Railroad’s plans signal a potential rebirth in privately owned inter-city passenger rail service, something that hasn’t existing in the country for more than 30 years.

In Vermont, an energy entrepreneur is talking about creating a private passenger rail service, taking advantage of track upgrades made in the 1990s to create the Champlain Flyer, a commuter train that ran 13 miles from Burlington and Charlotte before being closed for cost reasons.

Boston Surface Railroad Co. was founded in 2012 by a team of Boston-area business leaders with entrepreneurial and management skills – although none with railroad experience, according to their official biographies. The company plans to “provide high-end passenger rail service between underserved cities with moderate to dense cross commuter traffic,” in the words of its company history.

It says it has $1.5 million in seed money from its founders and $4.5 million more through debt offerings for starting the service from Worcester to Providence, R.I.

In August, the company expressed interest in developing a northern service as well, running on existing track from Worcester to Lowell, Mass., then through Nashua to Bedford, using a bus or some other service to connect with the Manchester airport.

This week the company solidified that idea, when company president Vincent Bono appeared before the Nashua City Council seeking a memorandum of understanding as the first step in what he admitted would be a long process. The idea is so nascent that the company doesn’t even have the Bedford route on its website map, which shows a totally different possibility, called an “anticipated expansion,” running from Boston to Manchester on tracks near Interstate 93.

Nashua has been trying for years to get the state government to support to idea of extending MBTA passenger rail north from Lowell, Mass., so they jumped at this chance. Bono said any service is years away, depending on financing.

Creating inter-city passenger rail service is much more complicated than creating inter-city passenger bus service, partly because roads are public but most train tracks aren’t.

It isn’t enough for Boston Surface Railroad Co. – that name may reflect the U.S. Surface Transportation Board, which governs railroads and has given the project operational authority – to buy refurbished engines and cars, as it says it will do to save money, hire engineers and other staff, and build or spruce up train stations.

It also has to reach an agreement to pay Pan Am Railways for “trackage rights” on the line running along the western side of the Merrimack River, and coordinate with freight usage.

Pan Am, formerly known as Guilford, bought much of the old Boston & Maine tracks when that regional rail giant died three decades ago, including the lines that run up to Concord.

Among those tracks were lines running along the New Hampshire Seacoast, from the Massachusetts line into Maine.

No inter-city passenger rail had used those tracks since 1965 when plans were floated in the 1990s for Amtrak to create a service linking Boston and Portland, Maine. Negotiating trackage rights with Pan Am, and with the MBTA for use of tracks in Massachusetts, was a big part of creating the Downeaster service.

Barker said that the track in New Hampshire has the heavy rail – weighing 112 pounds per yard – needed for higher speeds on passenger service, although he didn’t know details of its condition and suitability for service other than freight. Creating the Downeaster cost some $50 million in line upgrades.