The 15-mile stretch of Interstate 10 between Lafayette and the Atchafalaya Basin Bridge will be expanded from four lanes to six in one the largest infrastructure projects the Acadiana area has seen in recent years.

Work could begin late this year or early next year on the first phase of the project, which Gov. John Bel Edwards highlighted at a Wednesday news conference in Lafayette.

The expanded lanes should be welcomed by drivers on a heavily traveled stretch of road known for unexpected and lengthy delays.

The roughly $300 million widening project, which will include two roundabouts at the I-10 interchange in Henderson, is funded in part by a $60 million federal grant aimed to improve freight corridors.

Freight traffic accounts for more than one third of the roughly 60,000 trips a day on that stretch of I-10, according to figures from the state Department of Transportation and Development.

"The whole point behind this grant is to get freight moving in Louisiana," Edwards said.

The first phase of the project is expected to go out to bid before the end of the year.

It will add a third lane from I-49 in Lafayette to the Breaux Bridge exit and from Henderson to the Atchafalaya Basin Bridge.

Construction time is estimated at about two years.

The second phase, which is not expected to go out to bid until the 2018-2019 fiscal year, will add a third lane in the section between Breaux Bridge and Henderson.

DOTD has pledged to keep two lanes of traffic open at all times on the interstate during construction.

In addition to widening I-10 between Lafayette and the Basin Bridge, the project calls for a complete rebuild of the existing road.

DOTD's Acadiana regional administrator, Bill Oliver, said there has been no major reconstruction on that portion of I-10 since it was built in the 1960s.

"That's original pavement," he said.

Edwards on Wednesday touted the I-10 project as a key early component in his administration's plan to make roads and other transportation infrastructure a priority.

"We have to stop pretending that what we do is enough," he said.

The $60 million federal grant for widening I-10 allowed the state to shift money that had been set aside for the project to other work, including a new Washington Street I-10 exit in Baton Rouge near the Mississippi River Bridge – a notorious choke point in the city.

Follow Richard Burgess on Twitter, @rbb100.​