Waymo has paused its robotaxi service in four cities, including Atlanta, San Antonio, Dallas, and Houston, due to issues with its vehicles navigating flooded roads. The company is working to develop a solution to avoid flooded areas, but its current software update has not been sufficient. Waymo's robotaxis have been getting stuck in flooded streets, and the company is cooperating with the National Highway Traffic Safety Administration (NHTSA) to address the issue. The pause in service is a precautionary measure to ensure safety.