Ridership on a second Amtrak train from St. Paul to Chicago could exceed 150,000 passengers a year, but Minnesota and Wisconsin would have to pay for operating shortfalls, a new rail study concluded.

The study, commissioned by Amtrak at the request of Minnesota and Wisconsin state transportation agencies and the city of La Crosse, Wis., comes in the midst of metro-area rancor over transit funding. It projects $46.4 million in equipment purchases, as much as $175 million in railroad improvements and about $6.6 million a year in state-financed subsidies to cover the difference between ticket revenue and the costs of operating a second train.

The current, once-a-day Amtrak train that crosses Minnesota “provides little schedule flexibility to travelers in the corridor,” the study concluded.

“Obviously anything we can do to expand service to our residents will help with economic development,” said Washington County Commissioner Karla Bigham, who has taken a lead on east metro transportation issues. “Businesses really do want additional options to have multimodal transportation to move their services and goods.”

If money is found to finance a second line, the train most likely would run from Union Depot in St. Paul to Chicago, although future extensions to Minneapolis and St. Cloud would also be considered. The proposal is independent of discussions about starting high-speed rail service to Chicago.

A second Amtrak train would follow the same route as the current one, with a top speed of 79 miles per hour.

How it would be funded depends first on an environmental review — required before Minnesota and Wisconsin can apply for federal grants — that could be done this summer and fall. Federal regulations limit Amtrak’s financial contribution to the first 15 percent of operating costs.

The study findings arrive amid a flurry of recent debate over state funding for transit.

Earlier this week, after much controversy, the Southwest Corridor light-rail route was shortened to save $250 million. This spring, despite discussion, legislators took no action on a request for $3 million in transit planning for the Gold Line, a bus-rapid transit commuter route that will follow Interstate 94 from St. Paul east to Woodbury.

“We need to look at rail service in general,” said Bigham, a former Cottage Grove legislator and current chairwoman of the Red Rock Corridor Commission, a task force representing counties and cities planning the Red Rock bus-rapid transit line from St. Paul to Hastings. Any collaboration with railroad companies to expand service and improve rail safety is important, she said.

But Washington County Commissioner Lisa Weik, chairwoman of the Gold Line task force, said she thinks the long list of transportation deficiencies in Minnesota will discourage action on the Amtrak proposal.

“I don’t see this going anywhere, even if it takes several years,” Weik said. “I think the voters, the taxpayers, would say there are too many transportation projects, too many crumbling roads and bridges that are fracture-critical, too many safety concerns in the state of Minnesota to be talking about cost-sharing with Amtrak.”

Weik said she would want to know more about the extent of passenger demand for a new train and how it would fit with a proposed high-speed train and a desire by the city of Rochester to link to it.

The Amtrak study, in the works since 2012, concluded that all four route scenarios evaluated “compare favorably with annual ridership on similar corridors across the country.”

The study explored a Minneapolis-to-Chicago route, a St. Cloud-to-Chicago route with a stop at Target Field Station, and a St. Cloud-to-Chicago route with a stop at Fridley Northstar Station. However, the 411-mile route from Union Depot to Chicago was considered the most practical.

Under that scenario, trains would leave St. Paul daily and would consist of two diesel locomotives, four bi-level coaches, two bi-level snack coaches and two bi-level “cab coaches,” accommodating as many as 270 passengers, the study said.

The Amtrak train currently serving Minnesota — the Empire Builder — travels between Chicago and the West Coast. Eastbound trains leave St. Paul in early morning, westbound trains leave the city late at night.

The Empire Builder once was considered Amtrak’s most popular overnight train and had recorded several consecutive years of ridership growth before the recession. Currently, about 100,000 passengers ride it annually between St. Paul and Chicago, the study said.

Amtrak has struggled with timetables in recent years because of track deficiencies and the heavy oil train traffic through Minnesota and North Dakota. The new study acknowledges that problem, saying that the “complexity of railroad operations and infrastructure issues are considerably greater west of St. Paul because of the number of host railroads, rail congestion and capacity issues.”