A new search for ways to reroute freight train traffic to make room for the Twin Cities’ biggest light-rail line came under fire Thursday night by St. Louis Park residents who opposed earlier plans for moving the freight to their city.

The Metropolitan Council, the agency overseeing the Southwest Corridor light-rail project, laid out its latest search for an acceptable freight reroute to a skeptical audience of 250 in St. Louis Park.

“We can’t see how it could wind up any different,” said Frank Freedman, adding that rerouting freight from Minneapolis to St. Louis Park “has been looked at and re-looked at.”

The session was part of a broader effort by the agency to reassure critics of the Southwest light-rail project that alternatives to its plan have been fully explored and ruled out.

Existing freight train traffic in the Kenilworth corridor of Minneapolis has become an obstacle to building the Southwest light rail there. After St. Louis Park residents objected to having the freight moved to their community, agency planners proposed keeping it in the Kenilworth corridor and digging $160 million tunnels next to it for the light rail.

But Kenilworth area residents balked at accepting the light rail and keeping the freight trains, and Minneapolis officials said the Met Council hadn’t exhausted all options for rerouting the freight. Last fall Gov. Mark Dayton intervened and the project was delayed so that the agency could allay concerns by taking a fresh look at ways to relocate the freight.

A study of the possibilities is expected to be released later this month. An informational display at Thursday’s session asked, “What makes freight rail relocation so difficult?” Its answer: “With freight traffic on many lines near capacity, relocation options are limited.”

The display explained that federal approval is needed for freight route changes and that railroads have considerable clout in the process. The Twin Cities & Western Railroad, which uses the existing track in the Kenilworth corridor, objected to some previous reroute options through St. Louis Park. The most recent option — putting the tracks on two-story berms in the suburb at a cost of $200 million — was opposed by residents and rejected last year by a panel of metro leaders.

“Raising the trains 20 feet in the air seems a little scary,” Brad Smith of St. Louis Park told public officials Thursday in a packed recreation center room. He cited recent train derailments in North Dakota and elsewhere.

A woman at the session advocated a cheaper option of running the light rail at ground level next to the freight trains in the Kenilworth corridor instead of putting the freight on berms in St. Louis Park or building tunnels for the light rail.