The Massachusetts Department of Transportation (MassDOT) is conducting the Northern Tier Passenger Rail Study to explore the feasibility of passenger train service between North Adams and Boston, as called for by the commonwealth’s 2020 budget.

On Jan. 11, MassDOT held a virtual workshop releasing details to the public about a possible extension of the Massachusetts Bay Transportation Authority’s (MBTA) Fitchburg line to North Adams via Greenfield, using pre-existing railbeds.

The study is considering two alternative plans, one costing $1.04 billion and the other costing $2.18 billion. Both remain early in their planning stages and no plans have been approved or construction begun thus far.

The route would follow the Northern Tier rail corridor, part of the former Boston and Maine rail line running between Troy, N.Y., and Boston. Trains would run through the Hoosac Tunnel, which was once the longest in North America, lending North Adams the nickname “Tunnel City” — and a local coffee chain its name.

Currently, the line is used by freight traffic and portions are rated for maximum passenger rail speeds of 30 miles per hour. The $1.04 billion plan would fund limited track upgrades, among other infrastructure improvements, and would allow for travel times of approximately four hours in each direction from North Adams to Boston. The $2.18 billion plan would allow for greater upgrades and shave more than one hour off of the travel time.

According to The Greenfield Reporter, the civil engineering firm hired by MassDOT estimated that, under the cheaper option, 220 to 440 riders would use the train service in North Adams each year and 2,420 to 6,600 would use the train service in Greenfield. Meanwhile, if the more expensive plan were adopted, an estimated 1,430 to 4,180 riders each year would use the train at North Adams and 7,370 to 20,350 riders each year would use it at Greenfield.

Both plans would require the construction of a new train station in North Adams near Western Gateway Heritage State Park and other facilities construction and upgrades along the route. If built, the new train line could lead to new private investment in commercial and residential projects near the new train station, bolstering the region economically, according to State Rep. John Barrett III. Both plans would lead to transportation cost savings and have limited environmental impact, Paul Nelson, an engineer with HNTB Corporation, said to The Berkshire Eagle.

Members of the study’s working group include U.S. Senators Elizabeth Warren and Ed Markey, Mayor of Boston Michelle Wu, U.S. Congressman Richard Neal, and Mayor of North Adams Jennifer Macksey.