With a major decision looming on the Southwest Corridor light-rail project, funders pressed Monday to hold down the potential cost of running it through the Kenilworth corridor of Minneapolis near existing freight train traffic and bike trails.

An alternative — a more costly rerouting of railroad freight to St. Louis Park to make room for the LRT and trails in Minneapolis — was barely discussed by the panel of regional transit funding officials.

Hennepin County Commissioner Peter McLaughlin said there is “little if any real ability to compel” the railroad to move and that LRT planners “seemed to have run out of options” for rerouting freight traffic.

Transit engineers from the Metropolitan Council, the agency planning the LRT project, are expected to recommend a solution to the freight train problem later this week at a meeting of metro mayors and other leaders. Their primary option for keeping the freight in the Kenilworth corridor of Minneapolis includes sinking the LRT in two tunnels.

But the agency also is offering a cheaper version involving a single tunnel. And one member of the panel raised the prospect of cutting costs further by ditching both tunnels and running the LRT at ground level next to the freight and elevating the bike trail. The last option is opposed in Minneapolis, where some residents have threatened to sue.

Others expressed concerns that the project’s rising overall costs will come at the expense of other metro projects dependent on funding from a sales tax dedicated to transit in five Twin Cities counties.

“I got to go back to my constituents and explain all of this,” said Dakota County Commissioner Paul Krause, a member of the regional transit funding panel, called the Counties Transit Improvement Board.

The estimated cost of the Southwest line, to run from downtown Minneapolis to Eden Prairie, has gone from $1.25 billion to between $1.59 billion and $1.68 billion.

The freight rail traffic is the biggest contributor to increased costs and threatens the project’s future.

An option to place freight traffic onto two-story berms in St. Louis Park would cost $200 million and is opposed by the suburb and some residents who object to additional train traffic and say the berms would divide the community and compromise safety.

As an alternative, Met Council engineers are offering to keep the freight in the Kenilworth corridor alongside the bike trails and hide the future LRT in tunnels south and north of a channel connecting Lake of the Isles and Cedar Lake. It would cost $160 million and eliminate the planned 21st Street station. Nearby residents complain that digging the tunnels would harm the environment in the wooded corridor and that hundreds of LRT trains would still be exposed when crossing a bridge spanning the channel.

The agency has offered several cost-cutting measures, including digging only one tunnel south of the channel and running the LRT at ground level north of it. That plan would cost about $100 million and spare the station.

Ramsey County Commissioner Jim McDonough questioned why even less expensive plans aren’t among the finalists, including elevating the bike path. “We don’t want to get so locked in that we think we only have two solutions,” McDonough said.

Met Council transit developer Mark Fuhrmann said planners dropped the idea of elevating the bike trail because it would need to be 23 feet high and connecting it to existing bike trail would be difficult.

But at $55 million, the option would be about $100 million less than the two tunnels, a point made by Anoka County Commissioner Matt Look.

“At some point we’ve got to call $100 million real money,” Look said.