BOSTON — The rail line that stretches along northern Massachusetts to Greenfield and North Adams is a “strategic asset,” state transportation officials said in a new report this week. But the benefits of restoring mass transit to the region — at a cost of up to $2.96 billion — “may not outweigh the investment costs.”

The Massachusetts Department of Transportation has looked at six options for passenger rail service on the extension of the old Fitchburg rail line. MBTA commuter rail service on the line currently terminates in Fitchburg at the Wachusett Station, but the tracks continue west toward New York.

“I think restoring that rail service would be a game changer for the region,” Rep. Aaron Saunders told the News Service. “Sometimes people don’t realize it, but it’s not ancient history when you look back to a time when there was a passenger railroad connecting the eastern and western parts of the state. And restoring it would be a blessing in many ways.”

Benefits could include expanded housing and employment opportunities for state residents, according to Saunders. His district includes the town of Wendell, between Greenfield and Athol, where potential passenger rail stations are being discussed.

Public participation has been “significant,” Saunders said, and he has heard from residents of surrounding towns who commute east for work or medical appointments or who simply “want the ability to hop on the train and drive into town to see a Sox game without having to worry about driving, traffic and parking.”

The draft study is subject to a 60-day public comment period ending Oct. 12. It was released Tuesday, more than three years after its original publication under a directive from Parliament, which asked the agency to examine the prospects for passenger rail in the Northern Tier in a section of the 2020 budget.

Passenger service on the 140-mile line to North Adams continued until the mid-20th century, according to the report, and a 12-year model schedule was presented for resuming service. The schedule calls for securing funds in the first year and includes three years of planning and four years of construction.

The study found there were “challenges” in accessing federal funds for the project “under the current discretionary grant program criteria,” citing “fierce competition” for federal grants. A bill that would give Massachusetts more leeway to draw more from the federal government’s sizable grant pool has been on hold for months due to an unspecified dispute among Democrats.

In addition to track improvements funded by private owners, the study says the government may also need to contribute to some major improvements, such as “renewing” the 1877 Hoosac Tunnel, which runs directly through the mountains on the way to North Adams.

Of the six plans studied, the investigation found that stakeholders support Alternatives 3, 4 and 5, and are interested in adding more stops along the route in places like Charlemont and Williamstown, home of Williams College. All but one of the options studied would involve diesel-powered trains, even though the state is trying to transition to less polluting modes of transportation.

Alternatives 3 and 4, referred to as Electrified Service and Full Transit, achieved the highest estimated ridership of all plans. Electrified Service is estimated at 196,520 to 304,200 passengers per year and Full Transit is estimated at 168,040 to 255,460 passengers.

Although both systems are “more complex to plan and implement,” they are also more cost-effective due to the higher ridership these options entail and have the lowest annual maintenance costs per passenger.

The Electrified Service plan, which would include stations to the west in North Adams, Greenfield and Athol, would cost an estimated $2.96 billion. That is the highest capital cost of all six ideas, and about $1.32 billion of that cost would come from electrifying the line, something the other options did not consider. Annual maintenance costs were estimated at $97 to $151 per passenger.

The Full Local Service plan is estimated to cost $1.59 billion and includes stops in Shelburne Falls, Athol and Gardner. Annual operation and maintenance would cost between $116 and $176 per passenger, according to Department of Transportation estimates.

According to the study, passengers on both routes could travel from North Adams to Boston in just under three hours.

Other possibilities presented in the report include an extension to Albany, NY, with a total travel time from Albany to Boston of four and a half hours, and a “two-transfer trip” with a train from North Adams to Fitchburg and an optional transfer to a separate train to Boston.

“Given the estimated benefits and costs associated with each of the six alternatives, the cost-benefit analysis indicates that the benefits may not outweigh the capital costs required to implement them,” the study concluded.

MassDOT says more work is needed, including further developing “the markets, ridership, costs and benefits from a transportation planning perspective.”

The report called for the collection of “more accurate and timely” data on travel demand in the region, and for the creation of a new express service between Fitchburg and Boston to be explored. A coach route along the Northern Tier route should also be studied to “increase demand for future rail service.”

A coach line along what is now the Downeaster Amtrak line between Boston and Maine was successful, the report said, and demand in those communities grew in the years before the rail line opened.

The report also stressed the importance of maintaining the Northern Tier line for freight, calling the tracks a “strategic asset for the entire Commonwealth”.

Saunders said the timing of the study was “exciting” because the north-south Valley Flyer train, which runs from Greenfield up to Vermont and down to Springfield and New York, offers “another connectivity option” for his area.

“Making rail an option for people to travel not only north to south but east to west is a game changer for us,” said the Belchertown Democrat. “And I think combined with the planned east-west rail linking Boston to Springfield and Pittsfield, it will bring a transit vision that many people here are excited about to become a reality.”