New weigh-in-motion system reduces lane closures
Thursday, February 07, 2008 at 12:00:00 AM

SLIDELL, La. – The Louisiana Department of Transportation and Development (DOTD) announced Thursday that a new weigh-in-motion (WIM) system is keeping overweight vehicles off the hurricane damaged Interstate 10 Twin Span Bridge, and crews can now reduce the number of times per week that they close westbound lanes for maintenance.


The WIM, which became operational in November 2007, allows DOTD to accurately weigh all westbound trucks on I-10 between the Old Spanish Trail and the Oak Harbor exits. Between Dec. 3 and Jan. 16, an average of 52 overweight trucks per day were turned around and rerouted away from the Twin Span Bridge. Overweight trucks increase the amount of damage to the prefabricated-deck panels that replaced the portion of the westbound span damaged by Hurricane Katrina.


Beginning Feb. 11, DOTD will close lanes three times a week – Monday through Wednesday from 10 a.m-2 p.m. – instead of four times per week.


The I-10 Twin Span Bridge is the most inspected bridge in Louisiana and one of the most inspected bridges in the nation. The entire bridge is inspected by four inspectors every day. Lane closures on the westbound span are necessary to safely and accurately repair the deck panels.


Because fewer overweight trucks are crossing the bridge since the WIM opened, inspectors report a 20-percent decrease in the number of broken bolts that hold the deck panels to the bridge supports.


The westbound span has a 70,000-pound weight limit for tractor-trailer combinations. Weight-limit signs are posted at 6 miles and 3 miles before the WIM.


For maintenance schedules and more information, log onto or contact the DOTD Customer Service Center at 1-877-4LA-DOTD (1-877-452-3683) or e-mail