Louisiana has hundreds of needed road projects, the most important of which is the completion of Interstate 49. I-49 North from Shreveport to the Arkansas line will be completed relatively soon. Now we need to get serious about the much more expensive ($5.2 billion) completion of I-49 South.

The I-49 South project is basically an upgrade of U.S. Route 90 to interstate standards. Eighty percent of the nation's offshore oil and gas supply, almost 30 percent of the country's energy consumption, comes from or through Louisiana.

U.S. 90 makes this possible. Unfortunately, U.S. 90 has been operating over capacity for years, and by 2030 the deterioration will cause it to fail completely.

Completion of I-49 North and South will ensure that Louisiana can continue to meet America's energy needs, create an international north-south trade corridor from the

Louisiana Gulf Coast to Canada, keep our ports from losing business to Houston, improve hurricane evacuation, relieve traffic congestion, save lives, and create over 100,000 jobs.

So where do we get the money to finish I-49 South? The state does not have it; nor could we borrow it, even if we wanted to, under our constitutional debt limit. The feds have their own budget problems, starting with $14 trillion of sovereign debt. That leaves one possibility: someone else.

That "someone else" might be an infrastructure investment fund. An IIF raises funds from private investors to finance, design, build, operate and maintain a public project through a public-private partnership in exchange for a return on the investment, usually 5 to 7 percent per year.

There is, of course, no free lunch. An IIF expects a return on its investment, which would require Louisiana to come up with a guaranteed income stream over the life of the PPP.

A portion of the state's capital outlay budget could be dedicated to the project, but it won't be enough. The only other option is tolls, which is typically how PPPs are funded.

Support for tolls or a PPP for I-49 South could be mixed, as some will see tolls as a tax increase, and others will worry about allowing a private entity to manage a government asset.

But I do know this: There are no easy answers to the question of how to make I-49 South a reality and get this vital project built sooner rather than much later or not at all.

John Kennedy is the state treasurer of Louisiana.