Eighteen-wheelers and other large commercial trucks crossing the Clark Street bridge will be more aggressively fined beginning early Monday, the first move in a long-term overhaul of a structure city officials called a potential safety hazard.

Some local shippers, meanwhile, chaffed at being rerouted off of the main artery between the city’s major industrial center north of town and Interstate 20 to the south, and said they plan to fight the impending closure.

New signs put up Friday instruct large vehicles to avoid the Washington Street overpass and instead use the U.S. 61 North bypass about five miles to the north. Current signs restricting heavy loads from crossing the bridge – still open to cars, pickups and other passenger vehicles – are not being enforced, said Public Works Director James &#8220Bubba” Rainer.

The suggested detour would force rigs leaving the harbor to travel north on North Washington to U.S. 61, then south to the interstate, adding about 20 miles to their routes. Trucks returning to the harbor would have to make a similar loop around the city and the Vicksburg National Military Park.

&#8220They’re talking about putting us out of business,” said Riverside Construction Co. president Louie Miller, whose Washington Street business lies just south of the bridge and receives shipments from several businesses out of the harbor. &#8220The cost of deliveries to Vicksburg is going to go out the ceiling.”

Tickets for trucks crossing the bridge will carry a standard fine, said Deputy Police Chief Richard O’Bannon. Officers will stop vehicles they catch on regular patrols in the area, he said.

The bridge crosses railroad tracks near the entrance to the Isle of Capri Hotel-Casino complex and has steep embankments subject to erosion, which has led to past damage and recent plans to replace the structure entirely. A $5 million project, funded through Congressional appropriations, will close the bridge in the near future to all traffic for up to three years while construction is under way, Rainer said. That work will begin once the city has finished putting together a design for the new bridge and hired a contractor to take out the existing roadway and begin rebuilding.

Until then, Rainer said, the weight restrictions are necessary as a safety measure on an aging structure that a 2002 state inspection found had shifted about 1 1/2 inches to the east after partially collapsing in the mid-1980s, which closed the small section of Washington Street for several years. That closure came about a decade after the bridge’s south end had itself been replaced, Rainer said.

&#8220We’re going to have to start enforcing it because we feel it’s the safe thing to do,” he said. &#8220It’s old. It needs to be replaced.”

Miller, whose company worked on repairing the collapse in the 1980s, disagreed. He said the bridge has shifted twice as far as the state’s 2002 estimate, but was skeptical that the move affected its capacity to hold large vehicles or required a dramatic plan of action.

&#8220We’ve been watching that bridge for three years, and structurally the bridge in my opinion is a good bridge,” he said. &#8220They have a weight limit, but most trucks can cross that.”

During the previous closure, trucks turned off Washington Street onto Bowmar Avenue, taking them to Halls Ferry Road, a direct line to the interstate, said Miller, a route that includes some residential areas and narrower roads. He said Rainer had not returned calls when he tried to propose the Bowmar-Halls Ferry detour as an alternative.

Riverside Construction will file for business interruption with its insurance company and pursue possible legal action against the city to the &#8220fullest extent” based on the resulting investigation, Miller said. Other local companies have held off prospective legal challenges, but have also said their shipping routes would be interrupted by any closure of the bridge.

&#8220It would impact us greatly,” said Sandi Oakes of Anderson-Tully Co., who plans the lumber company’s trucking schedule. &#8220A lot of trucks use that route. That’s going to add to their inconvenience and their fuel costs, as well.”

Rainer said he had heard some of the complaints and sympathized, but that the safety of the bridge outweighed commercial interests.

&#8220I understand their concern,” he said. &#8220It’s going to place a hardship on a couple of them.”

Fire trucks, ambulances, school buses and garbage trucks are among the vehicles that will be forced to detour around the closure, but Deputy Fire Chief Rose Shaifer has said the emergency vehicles will work to map out the shortest routes around the closure.