Drivers using the Hood River-White Salmon Interstate Bridge should prepare for delays and extended closures November 10th through the 13th.  The Hood River-White Salmon Bridge Authority says crews will conduct preparatory field work on and near the bridge from 7 a.m. to 5 p.m. each day.  Travelers can expect intermittent rolling stops, with delays of up to 15 minutes, along with three to four full bridge closures each day lasting as long as one hour.  The work is weather-dependent, so exact closure times won’t be available in advance.  Crews will try to avoid peak travel periods and minimize disruptions.  The work, which includes drone operations, will help prepare for test pile installation expected early next year.  Engineers will use the test piles to study how the existing bridge responds to vibrations and other effects from pile installation.  That information will help guide plans for the future Hood River-White Salmon Bridge replacement.