Officials backing high-speed passenger rail service between the Twin Cities and Duluth say it will cost $500 to $600 million to get the line up and running, about half of the previous estimates that approached $1 billion dollars.

The price cut was among several details about the proposed Northern Lights Express (NLX) announced Wednesday by the Minneapolis-Duluth/Superior Passenger Rail Alliance, the group which is partnering with the Minnesota and Wisconsin departments of transportation to bring the long-talked and dreamed-about rail service to reality.

Plans call for four round trips per day between the Twin Cities and the Twin Ports starting in 2020. With trains traveling at 90 miles per hour, end-to-end travel time of approximately 2 ½ hours, the alliance said.

It's anticipated that passengers would take between 700,000 and 750,000 trips in the first year of the service in 2020 and grow to more than 1 million by 2040. It would cost about $17.5 million a year to operate line for the first five years. Most of that cost would be covered by fares, the alliance said.

Trains would operate on 152 miles of BNSF track and include stations in Minneapolis, Coon Rapids, Hinckley and Duluth, along with Superior, Wis.

The goal, the alliance said, is to begin construction by next year. In the meantime, the alliance must complete a final benefit and cost analysis and complete negotiations with BNSF. MnDOT is moving ahead with preliminary engineering and is about half way through the environmental review process, the alliance said.

If federal funding is available, NLX service could begin in about four years.

The last time passenger trains ran between the Twin Cities and the Twin Ports was in 1985 when Amtrak discontinued the service.