A group of metro leaders who face a crucial choice in the Southwest Corridor light-rail project debated a different question Wednesday: Could they decide without making a decision?

The issue arose unexpectedly when the head of the Metropolitan Council, the agency in charge of the project, proposed that the leaders reach a consensus on the most contentious issue without voting on it.

“A lot of head-nodding would be my hope,” Met Council Chair Susan Haigh told the group at a meeting.

Her proposal got strong and immediate pushback from the group of metro mayors and county commissioners. “So some of us are nodding and some of us are not. What do you do with that?” asked Hennepin County Commissioner Gail Dorfman.

The group, the Corridor Management Committee, is expected to make a recommendation next week on the major stumbling block in designs for the Southwest Corridor light rail: whether to reroute freight trains to St. Louis Park to make room for light-rail transit, or hide the LRT in a tunnel when it runs through the parklike Kenilworth corridor of Minneapolis.

The Met Council, which is overseeing the project, says there is urgency to resolving planning disputes this year in order to qualify for state funding next year and begin construction in 2015. The line would run nearly 16 miles from downtown Minneapolis to Eden Prairie, and with a price tag estimated at $1.58 billion to $1.82 billion, it is expected to be the most costly transit project in the Twin Cities.

The agency Wednesday also disclosed another cost: roughly 600 to 1,000 trees that would have to be removed from the corridor under two options being considered.

But members of the group seemed more bothered by the proposal to avoid a vote on the options involving rerouting freight trains or adding a tunnel. The costly choices have divided Minneapolis from St. Louis Park and residents within those communities.

“Voting clarifies things,” said Hennepin County Commissioner Peter McLaughlin. “There’s an inherent ambiguity when you don’t vote, when you do a sort of head-nodding.”

Several other members agreed that a vote was needed. “You can’t go through any other effective process other than to vote and explain why you’re voting in a particular way,” said Edina Mayor Jim Hovland.

Haigh said she’d prefer not voting because the group has only advisory power and members may or may not reflect the majority view of their city councils or boards. She said she’d reconsider whether to hold a vote next week.

Members of the group also questioned her decision to set aside 90 minutes for next week’s session, saying they’d need more time to evaluate options and make a decision.

“I don’t think that most of us have had the chance to have a discussion we really want to have about how much does the project cost, which of these various issues, decisions, options are the right ones,” said Hennepin County Commissioner Jan Callison. “We really need the chance to discuss this among ourselves.”

Haigh added 30 minutes to the scheduled time for next Wednesday’s meeting.

1,000 trees face removal

Met Council engineer Jim Alexander told the group that a shallow tunnel under consideration for the LRT in the Kenilworth corridor would require the removal of about 1,000 trees. The tunnel would be cut from above and covered after the LRT tracks were installed. The engineers did not calculate tree removal for a longer deep tunnel, which would be bored underground.

The option of relocating the freight to make room for the future LRT at ground level next to existing recreational trails would involve removing 600 trees.

“Both of those numbers are large,” said Peter Wagenius, a transportation aide to Minneapolis Mayor R.T. Rybak. “I’m more surprised by the lower number, that even under a single-train scenario, it would be as many as 600.”

“The city is going to make a case for aiming for preserving more if we can, particularly the fully grown trees,” he said.

The trees are on railroad and county property, but not on park land around a channel between Cedar Lake and Lake of the Isles.