MADRID — Traffic on the Route 345 bridge over the Grasse River is limited to 15 tons because of safety concerns.

The state Department of Transportation posted the limit Wednesday after inspectors noticed the vertical walls are shifting out. The bridge soon will be restricted to one lane, likely by traffic lights. The limit will continue until DOT repairs the walls.

The bridge is inspected monthly because the walls shifted in 2006. It was closed for a month that summer for repairs.

It's uncertain how long repair will take. The bridge is slated for an overhaul in 2010.