A planned privately funded tollway linking Illinois and Indiana cleared a key hurdle Thursday when a regional planning board in Indiana approved the project following months of debate. A similar board in Illinois approved the project in October.

Next step for Illinois and Indiana Departments of Transportation (IDOT, INDOT) is to secure federal approval for the $1.5-billion “Illiana” Expressway, a 47-mile corridor that would connect I-65 in northwest Indiana to I-57 and I-55 in northeast Illinois, about 58 miles south of Chicago.

If built, Illiana would be the first project of its kind in Illinois financed under a public-private partnership. As planned, developers would fund, construct and operate Illiana, then recoup their investment from tolls the roadway generated through 2052. Both Illinois and Indiana have begun seeking proposals from potential developers.

Transportation officials say Illiana would serve as a corridor for intermodal enterprise while relieving congestion on I-80, a freeway extending across metropolitan Chicago. Depending on tolls, INDOT estimates the roadway would accommodate 13,000 to 27,000 vehicles per day.

Illinois Gov. Pat Quinn and then-Indiana Gov. Mitch Daniels agreed to proceed with the project in 2010. Last summer, newly elected Indiana Gov. Mike Pence committed to the project at a conference in Chicago.

“I believe roads mean jobs, and today's vote on the Illiana corridor project brings us one step closer to construction jobs for northwestern Indiana,” Pence indicated in a statement onThursday.

IDOT estimates Illiana will create more than 9,000 construction jobs and 25,000 permanent jobs.

Assuming the project receives federal approval, construction could begin in 2015.