Aug 29 (Reuters) - The U.S. auto safety regulator investigating Tesla's Autopilot driver assistance system is demanding an explanation for a software change that allows drivers to keep their hands off the wheel for longer, risking collisions, documents released on Tuesday showed.
The National Highway Traffic Safety Administration (NHTSA) ordered Tesla to answer questions about the Autopilot change and produce documents in a so-called special order dated July 26. The NHTSA order did not compel Tesla to recall vehicles.