I haven't seen this posted yet so I thought I'd share what I just learned from Tesla support. I've been going back and forth with them about the fact that ever since upgrading to 2019.8.6 my car will just suddenly slam on the brakes when passing an exit because it thinks the speed limit has dropped to 25mph (it thinks I'm on the exit rather than flying past it). Turns out that according to them, this is not a bug, it's a feature. Here it is straight from the horse's mouth: I have been reviewing your vehicles logs remotely for the timestamp you have provided our team. It appears that after review the cause of your vehicle slowing down at certain locations is due to a new feature that was introduced in the latest firmware (2019.8.6) called Fleet Speed. This is currently normal operation for Autosteer and TACC while activated and as our fleet collects more data the functionally will become smoother overtime with firmware updates. I have included below, some more information about how the new Fleet Speed feature works. Feel free to reach out with any questions or concerns. Fleet Speeds helps to slow down the car to an appropriate speed when entering and exiting highways or driving on interchanges when Autosteer or TACC is active. Speed will be reduced to the average speed of the Tesla fleet on that road section, but will not exceed the speed limit set by the driver. The set speed on the UI will be reduced in increments of 5 mph or 10 km/h rounded up to match the average fleet speed, though speed will not drop below 25 mph or 40 km/h. As long as Fleet Speeds is active, an animation of the circle around the set speed value will be shown on the instrument cluster. Entering highways (on-ramp) Fleet Speeds might slow the car down (depending on current set speed), speed can change dynamically similar to how the fleet reported speed changes Once the car is on the highway, it will accelerate back to the previous set speed. Exiting highways (off-ramp) Fleet Speeds might slow the car down (depending on current set speed), speed can change dynamically similar to how the fleet reported speed changes If the driver wants to change the set speed using the stalk, Fleet Speeds will stop updating the set speed but still limit the driving speed to fleet speeds Upon leaving the exit, Fleet Speeds will be actively controlling the speed for at least 100 m (110 yd) up to 2 km (1.2 mi) until the next road speed limit is detected Fleet Speeds becomes inactive when either the new detected speed limit is set, or the previous set speed is restored. Fleet Speeds can't be deactivated but depends on the availability on maps data of the fleet's average speed. I especially like that note at the end that it can't be deactivated it, as they clearly anticipated my next question. This is ridiculous. They are going to get me in an accident because of this "feature". I have asked to be downgraded until they either fix the bug or give me a way to disable it. Let's see what they say.