Road users in the US may soon see self-driving cars without human controls under a pilot program proposed by the US National Highway Traffic Safety Administration (NHTSA). The agency is seeking public feedback on a proposed pilot to test vehicles "that lack controls for human drivers and thus may not comply with all existing safety standards" and do so in real-world scenarios, it said in a document released Thursday. As noted by Reuters, NHTSA said vehicles in the program may need features to disable them if a sensor fails or limit their maximum speeds. The pilot would aim to test autonomous vehicles rated as Level 4 and Level 5, which are respectively fully autonomous vehicles with a safe fallback mode, and fully autonomous vehicles without human controls, such as brake and accelerator pedals or steering wheels. NHTSA wants to know in what categories it should collect data from participants.