NEW ROADS — Soon, drivers headed south of Natchez will be able to cross the Mississippi River by bridge before entering Baton Rouge.

Construction on the longest cable-stayed bridge in the Western hemisphere reached a new milestone last week as the spans from both sides were connected.

The John James Audubon Bridge, which stretches a third of a mile over the Mississippi River connecting New Roads, La., in Point Coupee Parish and St. Francisville, La., in West Feliciana Parish, is still not accessible to the public for use, but should be completed in late 2011.

Construction on the spans began in early 2010 at the 500-foot tall towers on both sides of the river.

When complete, the $408 million project, which started in 2006, will be the only traffic crossing point on the Mississippi River between Baton Rouge and Natchez, a stretch of 90 river miles.

Work on the deck of the bridge is under way, and the project, when finished, will also include 12 new miles of approach roads.

The bridge will have four travel lanes, including 8-foot outside shoulders and 2-foot inside shoulders.

The new bridge is a part of the Louisiana TIMED Program, the single largest transportation program in the state’s history.

The program is designed to help enhance economic development in Louisiana through transportation projects.

Department of Transportation and Development Secretary Sherri H. LeBas said in a press release the new bridge will bring a lot of good to the areas involved.

“The bridge will reduce commute times and promote economic development while providing a safe and efficient travel route for freight and shipping,” she said. “The investment in the John James Audubon Bridge, as well as a total investment of $4.6 billion in Louisiana’s TIMED Program, is improving the quality of life for motorists, resident, and businesses by enhancing economic development.”

LTP is funded by a $.04 a gallon gasoline and motor fuels tax.