NHTSA Complaint #11498200 — 2018 TESLA MODEL 3

This summer while driving on interstate highways the Adaptive Cruise Control (with and without all other driver assistance/autopilot features enabled or disabled) would unexpectedly brake the car, slowing down by 10 or more MPH over 1-2 seconds, with no obstructions or vehicles in front of the car for hundreds of meters at least. This happened repeatedly, and we believe we correlated it to cases when the car came up over a low rise or bridge, and there was bright sun creating a small mirage in the distance on the highway in front of the car without any other vehicle in between to block the view. This seems to be a safety issue because at highway speeds, unexpected braking is very disruptive and startling to the driver, the passengers as well as anyone following behind who may not react in time especially on a clear sunny day with no obvious obstructions to take extra care of. * component: Adaptive Cruise Control (with or without other Autopilot ADAS features) * safety: Braking at highway speeds is disruptive to traffic and can cause accident (rear-ending, startling driver) * reproduced: Problem has not been reproduced by the vendor and I don't see any way to report it to the vendor * inspection: The components have not been inspected by others to my knowledge, this is based on software produced by or licensed by Tesla * warnings: no warnings were produced before or during the event, just .5g or so (not measured) of braking unexpectedly