Searching for new funds for roads and transit, DFL leaders are eyeing tolls for the future St. Croix River bridge between Minnesota and Wisconsin.

Charging drivers as much as $3 to cross the bridge could raise enough money to pay for roughly half the construction cost.

"It's a potentially important source of revenue," said Rep. Frank Hornstein, DFL-Minneapolis, chairman of the House transportation finance committee.

"I'm very open to it," said Charlie Zelle, Gov. Mark Dayton's transportation commissioner. "I think it needs to be explored."

While there are legal and political hurdles, the bridge tolls are among several ideas under serious consideration to close a gap estimated at tens of billions of dollars for transportation funding.

Raising the gasoline tax -- the traditional source of highway funding -- is another option favored by key lawmakers, including Sen. Scott Dibble, DFL-Minneapolis, chairman of the Senate transportation and public safety committee.

Dibble was on a governor's task force that recommended raising the gas tax by 40 cents a gallon over 20 years. Dayton declined to embrace the proposal, but he hasn't ruled out supporting some kind of gas-tax increase if the DFL-controlled Legislature passes one.

"He has not said ... 'I won't sign it,'" Zelle said.

Dibble said the Legislature should pass a gas-tax hike this session.

"What's politically possible is something we'll have to figure out," he said.

Hornstein said his panel will "strongly consider" an increase, adding, "If we were to do it, I would expect a much more modest proposal than what the task force proposed."

The last time the Legislature passed a gas-tax increase was in 2008. That 8.5-cent increase, phased in through 2012, generated funds for highways and bridges.

There is little enthusiasm among GOP legislators for another gas-tax increase.

"Very few members of our caucus are going to be able to support that," said Sen. John Pederson, R-St. Cloud, the ranking Republican on the Senate transportation and public safety committee, who noted that gasoline taxes hit rural drivers especially hard.

"It's too early in the session to talk about ... is it a good idea, bad idea," said Rep. Mike Beard, R-Shakopee, the ranking GOP member of the House transportation finance committee.

Transit funding sought

DFLers also are emboldened to push for greater state funding of the proposed Southwest Corridor light-rail line between downtown Minneapolis and Eden Prairie.

The federal government is expecting the state to kick in $125 million toward the $1.25 billion project, but so far the state has come through with only $7 million.

With Republicans controlling the Legislature last year, Southwest Corridor supporters sought $25 million and got just $2 million. Now that DFLers are in control, Southwest supporters are proposing $37 million to $118 million.

The money would be borrowed as part of the state bonding bill. The bonding bill needs Republican votes to pass, but will include projects that Republicans favor.

"The only way your project is funded is if you vote for the whole package," observed Rep. Alice Hausman, DFL-St. Paul, chairwoman of the House bonding committee.

DFLers also are supporting Gov. Dayton's call to increase the Twin Cities sales tax by a quarter-cent to support development of metro light rail and buses. If approved, the increase would bring the regional transit tax to a half-cent.

Supporters of St. Croix River bridge tolls said the revenue would help replenish funds spent repairing or replacing state bridges since the Interstate 35W bridge collapsed into the Mississippi River in 2007.

State to pay nearly one-third

Charging $1.50 for travel in each direction or $3 one-way could pay for 40 to 60 percent of the cost of the $676 million bridge, according to a 2011 study ordered by the Minnesota Department of Transportation. Minnesota state funds will pay for nearly a third of the total project, with Wisconsin and the federal government also contributing.

Even if the Legislature and Dayton embrace the idea of a bridge toll, Minnesota probably would need the support of Wisconsin and the federal government. Backers would need to act quickly to clarify the legality of tolls under federal law and probably conduct a new environmental assessment of the project before construction begins this spring. A comprehensive transportation bill hasn't been assembled.

"Tolling is only feasible if Minnesota and Wisconsin join in getting specific federal and state legislation passed," the 2011 study concluded.

Neither Wisconsin Gov. Scott Walker nor Dayton has taken a position on the tolls, their spokesmen said last week.

In Minnesota, GOP critics of the idea say that the bridge was approved on the premise that it would be free and that tolling would leave area motorists with few good alternatives.

But Hornstein said tolls on the St. Croix bridge would free up funds for other bridge projects in Minnesota.

"It's a lot of money, much more than I would have expected," he said.

Pat Doyle • 612-673-4504