After years of complaints but few solutions, Louisiana’s roads and bridges are suddenly sparking heavy interest in the Legislature.

Despite long odds, House Transportation Committee Chairwoman Karen St. Germain, D-Pierre Part, wants to boost state aid for roads and bridges by $675 million per year by increasing the state sales tax by 1 cent.

That would raise about $7 billion over 10 years — the most sweeping such proposal since a $3 billion highway plan died in 2011 within hours of being announced and without a single vote being taken.

A total of 15 projects would benefit, including construction of a new bridge over the Mississippi River near Baton Rouge, upgrades at the Port of New Orleans to handle bigger ships and improving Interstate 49 between Lafayette and Broussard.

Kenneth Naquin, chief executive officer of Louisiana Associated General Contractors Inc., said Louisiana is on the cusp of an industrial expansion of up to $150 billion. “We do not have the infrastructure to handle that,” he said.

“What do we do? Do we sit on our hands?” he asked.

In another uphill battle, St. Germain wants to enact a “floating” gas tax of up to 25 cents per gallon, depending on the average price at the pump. That could raise up to $750 million per year.

Both proposals — House Bill 778 to boost the sales tax and House Bill 777 for the floating tax — will soon get their first tests in the House Ways and Means Committee.

Meanwhile, Senate Transportation Committee Chairman Robert Adley, R-Benton, has offered a proposal that would accelerate plans to gradually move up to $400 million in motor vehicle sales tax revenue from Louisiana’s general revenue fund to one for transportation only.

Also, Adley and St. Germain are sponsoring a plan — House Bill 712 — that would boost the state’s gasoline tax by 4 cents per gallon, with the dollars dedicated strictly for parish needs.

Adley, who is sponsoring other key transportation bills as well, thinks something substantive on transportation will emerge from the 2015 Legislature, which ends on June 11. “I think there will be some momentum for it,” he said.

Motorists now pay 38.4 cents per gallon in state and federal gasoline taxes.

Other proposals — House Bill 208 and Senate Bill 123 — would drastically trim or eliminate the annual transfer of state road and bridge dollars to State Police.

Two additional measures — House Bill 157 and Senate Bill 160 — would require that at least 15 percent of future state surpluses be used for transportation infrastructure.

“We are just looking at some way of generating funds,” said state Rep. Mike Danahay, D-Sulphur, sponsor of the House version.

However, any road and bridge bills that boost taxes, as in past years, face massive hurdles.

Gov. Bobby Jindal opposes any tax hikes without corresponding cuts elsewhere.

“There is so much opposition from the Governor’s Office,” said Ken Perret, president of the Louisiana Good Roads & Transportation Association.

“The likelihood of those bills being enacted is pretty remote,” Perret said of the sweeping proposals. “But it is kind of setting the groundwork for the future.”

In addition, any tax increase requires the support of two-thirds of the House and Senate — 70 and 26 votes respectively — and 2015 is an election year.

Adley and St. Germain are term-limited, which means they are serving their final year in the Legislature.

All the discussions are taking place amid a $12 billion backlog of road and bridge projects and a $1.6 billion revenue shortfall to keep state spending at current levels.

The Legislature in 2008 voted to redirect about $400 million per year in motor vehicle sales tax dollars from the general fund, which finances a wide range of state services, to the state’s Transportation Trust Fund, which is for transportation only.

However, Adley said it is unlikely state revenue will meet the required thresholds before 2021 or so, which he said is too long to wait.

He is sponsoring Senate Bill 221, which would start gradually rerouting the money in 2016 and replace the loss of general revenue dollars with money from other sources.

Last week, House Bill 208 by Rep. Terry Landry, D-Lafayette, to gradually all but eliminate the yearly transfer of $65 million in road and bridge dollars to State Police, won approval in the House Appropriations Committee. It is set for a House vote on Monday.

St. Germain said that, without a sweeping tax hike, major road and bridge improvements simply will not happen.

“This is going to be a policy decision,” she said.

Follow Will Sentell on Twitter, @WillSentell. For more coverage of Louisiana government and politics, follow our Politics blog at http://blogs.the advocate.com/politicsblog.