Another federal safety agency, the National Transportation Safety Board opened an investigation Jan. 23 after the Austin district documented 23 incidents of Waymo driverless taxis illegally passing school buses. Waymo Chief Safety Officer Mauricio Peña provided a Jan. 23 statement about the Austin school bus incidents to local news station KXAN. State laws vary on whether cars must stop for school buses on four-lane roads or roads with medians. There have been previous traffic incidents involving self-driving cars from various companies, like failures to navigate traffic stops during power outages, MacCarthy said. But the school bus reports seem to have attracted more public attention because they involve young children, he said.