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Strange Autopilot Behavior

Strange Autopilot Behavior

This morning was driving to work around 5:30 AM on a four lane highway that was very straight and fairly empty using autopilot at 65 mph. All of the sudden as I was going under a bridge (had gone under a number more with no issues) the autopilot suddenly slowed the car down to 50 mph (though didn't try to swerve or anything) before picking back up to 65. It felt as if someone had slammed on the break as if they saw a speed trap. The only thing that seemed like it could have caused it was a car coming up on my right that was in its lane the whole time and got next to me, but wasn't swerving or anything like that. Has anyone had something like this happen to you?

VolleyballNE1 | 2019年11月13日

Search on google:
site:forums.tesla.com phantom braking

WhiteWi | 2019年11月13日

I have phantom brake in the same spot on the road on the way to my son's Preschool. I finally figured out why in my case. It has break in the double lines and car slows down to make sure it doesn't go to incoming traffic. Love the safety of the Robocar. Does it make me RoboCop? ))))

vmulla | 2019年11月13日

+1 @VolleyballNE1

EVRider | 2019年11月13日

There are a few typical causes for phantom braking:

1. The car “sees” an obstruction that isn’t there.
2. The car detects another car changing lanes and incorrectly “thinks” that car might get in your way.
3. The GPS road type or speed limit data is incorrect.

Most people have experienced at least one of these issues.

WEST TEX EV | 2019年11月13日

I think in this particular situation GPS may have erroneously switched to “bridge road” speed briefly. I have seen a similar situation:

1) in city autopilot restricted to 5 MPH over speed limit
2) highway unrestricted speed on autopilot
3) as I go on city street on autopilot (2 blue lines) under a highway overpass, speed briefly unrestricted & autopilot switches to “highway mode” (1 blue line) then switches back.

Suggestion to TESLA: Nav data must incorporate DIRECTION OF TRAVEL to not misassign speed limit AND/OR highway vs. city street designation.