Waymo suspends U.S. freeway rides, pauses Atlanta service ( Eric Thayer / Getty Images)Waymo suspended its robotaxi service on all U.S. freeways and paused operations in Atlanta, Georgia, on Thursday as the Alphabet unit works to update software related to construction zone performance and flooded road detection.San Francisco, Los Angeles, Phoenix, and Miami had all been served by Waymo's freeway routes, the company told Reuters. Street-level operations in those cities remain unaffected. Waymo also confirmed it paused service in Dallas and Houston out of caution ahead of forecasted severe weather across Texas, according to TechCrunch."We have temporarily paused freeway operations, as we work to integrate recent technical learnings into our software and expect to resume these routes soon," a Waymo spokesperson said in an email.AdvertisementAdvertisementThe Atlanta pause, which affects service offered through Waymo's partnership with Uber, followed an incident on Wednesday in which an unoccupied Waymo vehicle entered a flooded road during heavy rain and stopped for roughly an hour before being recovered, the company said. According to TechCrunch, Waymo said the Atlanta storm dumped rain fast enough that roads were flooding before the National Weather Service had put out any flash flood warning, watch, or advisory — thresholds that feed into the broader pool of signals the company uses when readying its fleet for hazardous conditions."Safety is Waymo's top priority, both for our riders and everyone we share the road with," the company said in a statement. "During a period of intense rain yesterday in Atlanta, an unoccupied Waymo vehicle encountered a flooded road and stopped."A TechCrunch report cited a statement from the National Highway Traffic Safety Administration saying the agency has been in touch with Waymo about the Atlanta situation and is prepared to act if warranted.The developments follow Waymo's recall of about 3,800 robotaxis earlier this month after the company identified a software flaw that could cause vehicles to enter flooded roads with higher speed limits. That recall stemmed from an April 20 episode in San Antonio in which a driverless Waymo entered a flooded lane amid extreme weather. When the recall was filed, the company acknowledged it had no finished remedy ready; in its place, Waymo pushed out a stopgap software update that curtailed vehicle operations in areas and timeframes where high-speed flooded roads were considered a heightened risk, NHTSA documents show.AdvertisementAdvertisementRegulatory pressure on Waymo extends beyond the flooding issue. A separate NHTSA inquiry remains open into a January crash in Santa Monica, California, where a Waymo struck a child near an elementary school; the company said the vehicle had slowed to roughly six miles per hour before impact and the child's injuries were minor. Both that agency and the National Transportation Safety Board have also launched independent probes into reports that Waymo vehicles moved around stopped school buses whose warning lights were active.