West bank bound lanes on the Huey P. Long Bridge in Jefferson Parish are closed until 5 a.m. on Monday while workers place girders for wider lanes.
State officials are urging motorists to use the Crescent City Connection in New Orleans or the Interstate 310 Bridge in Lulling as alternate crossings of the Mississippi River.
The Huey P. Long Bridge widening project will include three 11-foot lanes in each direction. The total width, including shoulders, will more than double from the current driving surface.
Completion is projected for 2013.