Interstate traffic backups from the Mississippi River at Vicksburg probably will not be as bad as they have been for the past two weeks, but they are expected to continue through the spring.

“We try to do night work where we can, but not for every project,” said Dustin Annison of the Louisiana Department of Transportation, which has overseen repairs to a connecting joint between roadway segments which has slowed traffic on the Mississippi side of the river for several days over the past two weeks.

A 1-inch thick metal plate used in the repair that caused drivers to slow down suddenly has been removed, with one more joint slated for a similar plate insertion “sometime between now and March,” Annison said. In the meantime, traffic should flow as it did before the extended delays started — likely at speeds less than the posted 60 mph just before the bridge.

“Engineers said people were coming to the plate and slowing down,” Annison said.

Work that requires the bridge’s two westbound lanes to be reduced to one will continue during daylight hours, he said, because daily traffic counts — an average of about 27,000, according to agency tallies — are not enough to warrant nighttime work for Lafayette, La.-based contractor C.E.C. whose workers are expected to be on the bridge between 6:30 a.m. and 5:30 p.m. through March 20.

The traffic is just “not an immense amount, interstate-wise,” he said.

Nighttime construction work is common in densely populated areas where counts exceed 150,000, Annison said, citing ongoing work to widen Interstate 10 in parts of Baton Rouge and a completed makeover of the I-10/610 interchange in New Orleans. In Mississippi, work to replace the Interstate 20 overpass at Gallatin Street in Jackson was done largely at night, as has been resurfacing on U.S. 49 in Hattiesburg.

The delays came with a $13.7 million effort begun in 2008 to stabilize bridge supports and shore up the span’s flexibility. The bridge, built in 1973, is  maintained by the Louisiana Department of Transportation and Development.

During the past two weeks, westbound drivers have experienced delays of up to hours as cars and 18-wheelers have been strung out up to eight miles through Vicksburg.

In addition, on Thursday, motorists headed in both directions were stopped for more than two hours after two barges broke free from a southbound tow on the river and struck a pier of the upstream U.S. 80 bridge.

Vicksburg businesses that employ Louisiana residents or are located near busy interstate exits eagerly await an easier commute.

“We have team members that live in Louisiana,” said Bess Averett, public relations manager for Ameristar Vicksburg. “It does cause an issue.”

River Region Medical Center, whose base is on U.S. 61 North in Vicksburg, also has many employees who live in Louisiana.

“I head west from the hospital and I soon as I enter I-20 from 61 North after 5 p.m., it’s already backed up,” said River Region Medical Center spokesman Diane Gawronski. “That’s how bad it’s been.” 

River traffic was not affected by the loose barges on Thursday, and the cause remains under investigation by the U.S. Coast Guard. Weather conditions were mentioned as a factor, as fog was visible on the river when the barges broke free just after 6 a.m.

The I-20 and U.S. 80 have passed inspections since the incident, officials of both bridge’s regulatory authorities said. Structural analysts with Baton Rouge-based G.E.C. Inc. checked a pendulum that monitors movement in the older bridge’s battle-scarred pier 4 and found no adverse effects of the fifth barge strike in 18 months and the first since the river flood of 2008, bridge superintendent Herman Smith said.

“It left a little paint behind,” Smith said. “Basically, what it did was bounce around it smoothly.”

Once completed, expansion joints on the Interstate 20 bridge will be able to move 24 inches to help the structure adjust to weather extremes, according to contract specifics.

A study in 2006 commissioned by LDOT revealed “significant movement” in the bridge’s E2 pier, closest to the Mississippi side, and cited “deep-seated rotational movement” around all the bridge’s piers.

Below-ground movement to piers holding up old U.S. 80, built in 1930 and owned by Warren County since 1947, has been measured farthest at pier 2. The first large pier from the Mississippi side has moved 9.94 inches since 1997, including .69 of an inch in the past year, according to the bridge’s inspection report for 2009. Bearings and concrete have been replaced atop the pier three times in the past dozen years.

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Contact Danny Barrett Jr at dbarrett@vicksburgpost.com