All traffic on Washington State Route 142 west of Goldendale will alternate through a single lane over the Spring Creek Bridge beginning on Monday.  The Washington State Department of Transportation will close the westbound lane following a routine inspection that found deteriorating concrete and exposed rebar underneath a portion of the bridge deck.  Shifting traffic to a single side of the structure allows vehicles to safely continue using the bridge without weight restrictions until repair work can be completed later this summer.  Temporary stop signs will be installed at both ends of the bridge along with directions for drivers to allow for on-coming traffic to clear before proceeding across.  The speed limit will also be reduced from 50 miles per hour to 25 miles per hour.  The SR 142 Spring Creek Bridge was built in 1950 and carries about 700 vehicles each day.