The Minneapolis City Council voted Friday to spend up to $1.2 million to install a huge culvert under the south end of the Interstate 35W bridge for a bike trail that's likely years away.

Defenders of the plan say it's a one-time chance to preserve a route that otherwise will be closed permanently by the bridge abutment.

But City Council critics say the price is too high.

"We're being held hostage," said Council Member Scott Benson.

The 230-foot tunnel is intended to eventually carry a bike-pedestrian trail connecting Bridge 9 at the University of Minnesota with 13th Avenue. City engineers say that allows a better university-downtown connection than detouring to W. River Parkway or Washington Avenue.

The price covers only the cost of installing a culvert that's 20 feet wide and at least 10 feet high. The trail won't be built until the city finds the money to pay for it, possibly not until 2014.

The council approved the money by an 8-3 vote, although the Department of Public Works said it has higher bike priorities elsewhere. Benson, Lisa Goodman and Don Samuels opposed the spending; Gary Schiff, Robert Lilligren, Elizabeth Glidden, Betsy Hodges, Cam Gordon, Diane Hofstede, Paul Ostrow and Barbara Johnson voted for it. Glidden tried to cap spending on the tunnel at $900,000, but the effort failed on a 7-4 vote.

City public works officials last fall estimated that the tunnel would cost about $800,000; they said Minnesota Department of Transportation officials informally estimated closer to $500,000.

But last month MnDOT forwarded a $1.39 million estimate from contractors Flatiron Constructors and Manson Construction, including a 19 percent markup.

The council made clear it expects its staff to negotiate a better price.

Flatiron didn't respond to a request for comment.

Had the proposed bike trail been included in the city's 2001 bike plan, federal bridge money would have paid for the culvert, said Jon Wertjes, the city's traffic director, Now the city likely will use state aid previously earmarked for railroad crossing safety improvements.

Steve Brandt • 612-673-4438