The chairwoman of the Louisiana House Transportation Committee said Thursday that she is sponsoring a one-cent state sales tax hike for roads and bridges that would raise $675 million per year.

State Rep. Karen St. Germain, D-Pierre Part, said the increase, which faces massive political hurdles, is needed to tackle Louisiana’s $12 billion backlog of transportation needs.

“What we want to do in new capacity, new infrastructure, is going to take money,” St. Germain said in an interview.

The tax hike would raise about $7 billion over 10 years.

Gov. Bobby Jindal has repeatedly said he opposes any tax increases unless they are offset by corresponding spending cuts elsewhere.

Tax hikes require the approval of two-thirds of the Legislature, which is a daunting 70 votes in the House and 26 in the Senate.

In addition, the state faces a $1.6 billion shortfall to keep state spending at current levels, which has sparked other revenue-raising proposals.

St. Germain said that, while she does not like taxes more than anyone else, “at the end of the day, we are either going to make it happen” or traffic congestion will remain the same.

State lawmakers are up for re-election this year, and a new governor also will be elected.

However, St. Germain cannot seek more time in the House because of term limits.

The session began on April 13 and ends on June 11.

State transportation problems have triggered arguments for years amid limited dollars to tackle the needs.

Previous plans to find more money have gone nowhere.

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

Residents of East Baton Rouge Parish pay 9 percent in state and local sales taxes.

The state rate is 4 percent.

St. Germain was one of the leaders of a special study on transportation needs last year.

That panel suggested a variety of modest fixes without endorsing any comprehensive plans.

“People were afraid to say the tax word,” she said.

The sales tax increase is House Bill 778.

The proposal, which is supposed to be in effect for a decade, is aimed at 15 projects, including construction of a new bridge over the Mississippi River that would connect La. 1 to La. 30.

Others on the list include the reconstruction of the interchange at Loyola Drive and Interstate 10; replacement of the Belle Chasse Tunnel with a four-lane bridge on La. 23; widening the I-10 Bridge over the Calcasieu River in Lake Charles; and upgrading U.S. 90 to interstate standards between Lafayette and Broussard.

St. Germain said she also will sponsor a separate “floating” state gasoline tax increase.

Under the plan, the special tax would be 25 cents per gallon if prices fall below $3 per gallon, based on an average over the previous six months.

If the price is between $3 and $4 per gallon, the tax would be 15 cents.

If prices at the pump go above $4 a gallon, the tax would drop to 10 cents a gallon.

How much it would raise is unclear.

The floating tax plan is House Bill 777.

The bills will be heard in the House Ways and Means Committee.

No hearing date has been set.

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