Two U.S. senators on Monday urged the country’s auto safety regulator to investigate reported failures of Tesla’s Full Self-Driving system to detect and safely respond to railroad crossings, citing risks of “catastrophic” collisions. The Full Self-Driving system, according to Tesla’s website, allows a vehicle to drive occupants “almost anywhere,” handling everything from route navigation to lane changes, steering and parking, but still requires supervision by a human driver. Tesla’s Full Self-Driving system, which is more advanced than its Autopilot system, has already been under investigation by the NHTSA. The two senators said the NHTSA should consider imposing limitations on Tesla’s use of the system. The NHTSA is also scrutinizing Tesla’s deployment of self-driving robotaxis in Austin, Texas, launched in June.