The Mississippi Transportation Commission recently sent a letter to Congress opposing changes to vehicle weight limits on the Interstate Highway System.
Changes would potentially allow six-axle Twin-33 trucks on the road. The trucks would violate a formula established in 1975 to protect the structural integrity of bridges, the commission said.
Truck must be less than 45,000 pounds to remain compliant.
Heavier trucks take 22 extra feet to stop and have a higher crash rate than smaller trucks, according to the U.S. Department of Transportation (DOT).
Nationally, one in nine bridges is structurally deficient, according to the American Society of Civil Engineers, and in Mississippi, the rate is one in eight.
“An 18,000-pound truck axle does over 3,000 times more damage to pavement than a typical passenger vehicle axle,” the commission said. “Increasing the weight of a heavy truck by only 10 percent increases bridge damage by 33 percent.”
The commission’s letter was signed by Chairman Dick Hall, Northern District Commissioner Mike Tagert, and Southern District Commissioner Tom King.
Those who support a change in legislation said larger trucks are safer and more efficient. The DOT, however, released a report to Congress in 2016 and found there was not enough data to support that claim and recommended no changes be made to weight limits.