Running consistent passenger rail service for 140 miles through northern Massachusetts communities to connect North Adams and Boston could attract hundreds of riders per day, but would also require hundreds of millions of dollars in up-front capital costs, state transportation officials concluded.

Wrapping up a study of Northern Tier Passenger Rail options, the Department of Transportation said the six options examined for a route from the state’s northwestern corner to its eastern capital would require anywhere between $878 million and $2.9 billion in investments.

Each scenario envisioned “could provide economic benefits for the region, in proportion to the magnitude of the total project costs,” officials wrote in a 112-page report summarizing their findings.

The final report was released on Nov. 27, less than two weeks after state Sen. Jo Comerford and dozens of advocates and business leaders, as well as state and local officials, rallied in support of the Northern Tier Passenger Rail at the John W. Olver Transit Center in Greenfield.

State officials say the idea that would likely draw the most passengers is the most expensive one: electrifying the rail right-of-way stretching from Fitchburg through Athol, Greenfield and North Adams.

That could attract between 196,520 and 304,200 riders per year, or roughly 540 to 830 per day, the analysis found. It would also require about $2.9 billion of capital costs, plus another $29.5 million in annual operations and maintenance costs.

The price tag for that option as studied is likely even higher because the model assumed electrified Massachusetts Bay Transportation Authority (MBTA) commuter rail service from Fitchburg to Boston’s North Station, a stretch where diesel trains are currently used.

Most of the projected ridership is “concentrated east of Fitchburg,” project officials wrote.

“The rail along the Northern Tier corridor is a strategic asset for the entire commonwealth and should be treated as such,” they wrote. “Given the competitive options for freight service that this route offers, the societal and environmental benefits of freight rail, as well as utility for mitigating increasing climate risks, ensuring a long-term future for this route is warranted.”

If the state were to embrace the all-electric option, study authors estimate it could provide train service from North Adams to Boston in about two hours and 50 minutes — roughly equal to the time that trip takes by car. Lower-cost options would offer rail trips that are longer than driving, MassDOT estimated, which could reduce demand and keep more motorists in the status quo.

Although railroads cross the full width of Massachusetts, passenger service is not readily available from one end of the state to the other.

The MBTA’s commuter rail network only goes as far west as Worcester and Fitchburg. Railways west of that, owned by CSX and Norfolk Southern, host infrequent Amtrak service as well as freight trips.

Transportation advocates have been pushing for years for state leaders to embrace a passenger rail expansion, arguing that fewer residents would need to drive — clogging up roadways and spewing emissions — if they had a train option, and that more people could access lower-cost housing in western Massachusetts with train service.

The state has secured some preliminary federal funding toward east-west rail, which would expand service west from Worcester to Springfield, but some local leaders want MassDOT to consider the route farther to the north.

Lawmakers in the fiscal year 2020 state budget instructed MassDOT to study the Northern Tier option, which led to the study published last week.

The report outlined additional steps — which will require more funding — that could help craft any decision, such as examining motor coach service as an interim, lower-cost step and crafting an economic development strategy for the area.

Experts need to learn more about travel demand in the area, authors wrote, including the market for trips between New York City and Berkshire County.

“More granular and current Northern Tier travel data, including any COVID-19 pandemic-induced changes, would be beneficial,” they wrote. “This could include a closer examination of traffic associated with communities in Vermont and New Hampshire and with area academic institutions. Understanding the Albany market could affect the potential for the western section of the Northern Tier.”