NHTSA Complaint #11540531 — 2020 TESLA MODEL 3

I have had multiple incidents of sudden speed reduction on major hi ways. (us 287 and I 25). Usually these incidents occur when I am traveling north (increasing elevation and later in the day), but that is not always the case. The events appear to be totally random, but result in a speed reduction of 70mph to 40mph rapidly enough that loose items (including pets) fly. on occasion I have had to be very quick to accelerate to avoid being run over by a tailgater. I scheduled a service appointment, but was discouraged from doing so by Tesla Service people who said “the car is still learning”. The fault has not improved. If anything it happens more frequently. At this point, I would say we travel “on edge”.