PORTLAND — Lawmakers and rail enthusiasts spent Tuesday pushing legislation that would make it easier to expand passenger train service from Portland to Lewiston-Auburn, but the Maine Department of Transportation has a bigger plan.

The Maine DOT’s draft plan sets out goals for $125 million in passenger rail investments between 2014 and 2019 — mostly using federal funds — and a range of other projects proposed to boost freight rail service.

The study and bills come at a time of big additions and changes to state railways, with the pending connection of Pan Am’s tracks to the International Marine Terminal expected this summer, a lull in paper shipments with the mill closure in Bucksport and the operation of the Central Maine & Quebec Railway under new ownership.

The big picture calls for broad investment, some with unknown costs. For passenger rail, studying a Portland-Auburn extension is one part of a suggested effort to preserve existing rail corridors in anticipation of future transit needs, including long-term investments to study the possibility of commuter rail service in Greater Portland and an intercity rail service, extending Amtrak’s Downeaster from Portland to Montreal.

Supporters point to increasing revenue and ridership for the Downeaster, operated by the Northern New England Passenger Rail Authority, which gets about 53 percent of its funding from the federal government and state of Maine.

For freight, the work ahead is more extensive as the study notes many of the state’s railways have weight and height limits that make them less competitive with other shipping options. At the same time, rail investments also are driven by customer demand, which in Maine has typically been from the paper industry.

For freight, the report calls for the state to continue investing about $1.5 million every two years in specific industrial rail projects, continue to preserve specific rail corridors, invest in hubs where railroads connect with other forms of transportation and work long-term to address the weight and height restrictions on much of the state’s tracks, projects for which the cost is not known and estimated completion date is beyond 2018.

But for freight, planning is driven by market demands. Nate Moulton, head of the Maine Department of Transportation’s Office of Freight Transportation, said while the five-year plan provides overarching goals for his department, development is driven primarily by the private sector.

While Maine’s paper industry has been on a steady employment decline, the industry — as noted in the DOT plan — follows the trend of declining employment but sustained or increasing output for manufacturers as they invest in new technologies and more efficient production methods. In short, the fact that Maine has fewer papermakers does not translate directly to a commensurate decrease in the delivery of papermaking materials to mills in the state.

However, the paper industry’s travails in 2011 caused the former Maine, Montreal & Atlantic Railway to abandon 233 miles of track in northern Maine, which the state bought for $7 million to allow trains to keep delivering materials to manufacturing customers along the way.

Forest products still make up the bulk of the demand for shipping on rail lines. Projects at Sappi Fine Paper in Skowhegan, Woodland Pulp in Baileyville, Hancock Lumber in Pittsfield and Irving Forest Products in Ashland receive a share of the money DOT gives each year to specific rail projects through its Industrial Rail Access Program.

Dependence on the paper industry can be a challenge for rail infrastructure investments, according to the DOT’s latest five-year plan, as shippers need customers lined up before they can justify investing in new rail lines. For shippers, the report found that Maine’s rail system is not as reliable as trucking to provide timely deliveries on short notice, or “just-in-time” shipments of goods.

Oil producers have been one of those new shippers nationally, but not in Maine. The surge in domestic production has led to more shipments of crude oil and other fuels via rail in the U.S. and Canada, raising widespread safety concerns in the wake of the disastrous July 2013 explosion in Lac-Megantic that killed 47 people. While oil shipments by rail continue in other parts of the country, shipments through Maine largely stopped after the deadly accident.

The first crude oil shipment in nearly a year came through Maine in February, traveling on Pan Am lines through Waterville and across to the Northern Maine Junction in Hermon, where Pan Am tracks intersect with the Central Maine and Quebec Railway. Cameron Crawford, an 18-year-old Hermon resident, was one of a few railroad enthusiasts to document the train’s trip through Maine.

John Giles, president and CEO of CMQ, confirmed his company received the 60-car shipment in Hermon, where it then traveled to Brownville Junction on CMQ lines. It continued on to New Brunswick via the tracks of the New Brunswick Southern Railway subsidiary, Eastern Maine Railway. Both of those lines are owned by Irving, which has refinery in Saint John, New Brunswick.

Giles said he could not comment on the reasons for the shipment, which was the first crude oil delivery through the state since March 2014. Mary Keith, a spokeswoman for the New Brunswick Southern Railroad, said she could not comment on a customer shipment.

Spokeswomen for Pan Am and Irving did not respond to requests for comment about the shipment.

Propane has been on the rise, but figures are difficult to track. As noted in the DOT’s rail plan, oil and propane shipments have both been on the rise nationally since 2011, including shipments from the central U.S. to and through Maine, but exact figures are hard to track.

“Adequate data is not yet available, but indicators suggest a continuation of growth in this market for both rail and maritime trade,” the report states.

The Maine Department of Environmental Protection tracks crude oil shipments, not propane, but the industry newsletter Atlantic Northeast Rails & Ports reported Moulton said during a February meeting about rail infrastructure planning at the Greater Portland Council of Governments that propane shipments in Maine have shifted mostly to rail in the past five years.

Regardless of shipments, the state report identifies Maine’s key transport routes, not just rail (with few surprises). The state report notes that 90 percent of all shipments spend at least some time on trucks, traveling mostly through six transportation corridors largely connecting with state’s major metropolitan areas and its three major ports.

Specific to railroads, the report identifies critical corridors as Pan Am’s Brunswick-Boston line, the Portland-Auburn-Fryeburg combination of railroads, Pan Am’s Portland-Bangor line, the CMQ’s Searsport-Brownville Junction-Millinocket line the network from Vanceborough-Brownville Junction-Jackman, the Eastport rail connection and the railroads connecting Millinocket-Madawaska-Van Buren.