PORTLAND/SOUTH PORTLAND - The Maine Department of Transportation will be replacing the last of four span locks on the Casco Bay Bridge on Wednesday, August 2nd. This work will require a traffic restriction on the bridge. Vehicles weighing more than 25 tons (50,000 pounds) will not be permitted to cross the bridge between 8:00 a.m. and 3:00 p.m. on Wednesday. In the case of rain, this work will be pushed to Thursday, August 3rd. MaineDOT will also use message boards to alert drivers of the temporary weight restriction.