Driving on the open highway in New Mexico, our Tesla Model 3 had multiple cruise control failures. I noticed that it was using adaptive cruise control, meaning it slowed down automatically when approaching slower vehicles. Neat. Didn’t realize this was a feature. Except at one point at highway speeds the car began to rapidly decelerate. It was about as scary as anything I have experienced. Like the brakes were jammed on, for no apparent reason. I briefly panicked and tapped the brake which turned off the cruise control and returned the car to normal operations.

There were several large trucks ahead of us, passing each other and I assumed that was the problem. I also assumed this was a rare event. I was wrong on both counts. A few minutes later, with no large trucks ahead of me, the car began to rapidly decelerate. With a bit less panic, I tapped the brake again and the car returned to normal.

We were on a blacktop road in the west on a clear sunny day and there were these “mirages” where the road ahead begins to look like water. This seemed to cause the deceleration. I (somewhat foolishly) turned on the cruise control again and within a few minutes it failed again. Not scientific but it seemed to be connected to these road mirages. A quick search shows lots of people having trouble with cruise control, some calling it unusable.

i will say it was a very, very dangerous situation. Maybe it’s the adaptive part. I really only want standard, old fashioned cruise control that keeps a constant speed. Hope I can just turn off the adaptive part and get normal cruise control operation.