The Mid-Bay Bridge will be closed to all traffic from 11 p.m. to 5 a.m. Saturday and Monday as workers continue permanent repairs. Drivers will have to use alternative routes during the temporary nighttime closures. Repairs to the post-tensioning tendons, which are prestressed steel cables inside the bridge that reinforce concrete, are expected to be complete in the fall. Traffic on the bridge will remain limited to two-axle vehicles including cars, trucks, SUVs, school buses and limited EMS and first responder equipment only. Semitrailers and commercial vehicles will be required to use alternate routes until permanent repairs Bridge are complete. Variable message boards will be placed on both ends of the bridge to alert drivers about the temporary restrictions. The work schedule depends on the weather.