Waymo is recalling its massive fleet of autonomous vehicles over a defect that may pose significant safety risk, according to federal regulators.  The action follows an incident in which a driverless vehicle failed to come to a complete stop after encountering flooded road conditions on a high-speed roadway, the National Highway Traffic Safety Administration (NHTSA) said in a May 6 report.”Entering a flooded roadway can cause a loss of vehicle control, increasing the risk of…