Autopilot Change Speed Based on GPS for Europe



Autopilot (AP1 & AP2) in Europe (and Asia?) should change speed according to the GPS speed sign database and not road speed signs.


In AP1 the camera can read the speed signs and show them on the display. In AP2, while the car is showing GPS data for the speed limit on the screen, in Europe, Autopilot does not change speed according to this data. Use GPS-based speed limit data to change speed when on Autopilot instead of reading speed signs (AP1) unless the driver manually changes the speed setting.

Moderator: It’s been noted that some GPS database speed limit signs are way off the actual speed. With AP2 in North America, Tesla used to adjust the speed based on the GPS speed database but updates now use speed sign reading similar to AP1.



lightly edited by moderator
Category: CY3XS Applies to:
     Created 1-Jul-2018


Changing speed based on reading the sign is the only right way to do it (although GPS speed limit info is probably a lot easier). The actual sign on the spot always trumps whatever data is in the GPS database.

Btw, current AP 2.0 (firmware 2018.38.12) will reduce speed, but not automatically increase it again.
    Created 2-Jan-2019
I fully understand your concern but this can be just an option on navigation setup. We have similar options for driving for example creeping on or off. We can have an option like “AP speed control via GPS signals” and you can turn it off or on when necessary. You wouldn’t want to deprive a huge fleet of Tesla a around the world and even for yourself when this function can be used Most of times rather than buggy limits around you. Right?
    Created 11-Dec-2018
The speed limit detection/lookup is really buggy around where I live. There are some 35-mph zones that the car thinks are 50-mph zones. That gives me a really rude awakening when I engage TACC, as the car violently tries to rocket up well past safe speeds. So I would not want TACC to automatically adjust speed limits, or alternatively I would like to be able to fix the speed limit database (but I'm sure designing a UI to accomplish that would be more trouble than it's worth).
    Created 11-Dec-2018
I have AP 2.5 in MS built Feb 2018, and am running latest V9 software. I have never been able to verify that the car ever reads roadside speed signs. It seems to always use GPS and never read road signs.

The salesman told me on my test drive that the car reads road signs. Can anyone confirm this happening in a 2018 MS?
    Created 1-Dec-2018
I agree with you. I just cannot understand why AP2 can have less functionality than AP1! Even the surrounding cars now are all Teslas!!! In AP1 you can see trucks, bikes etc...

in Europe it is even worse sinc AP2 only shows the speed limit and it has no connection whatsoever with the Autopilot!

    Created 8-Jul-2018
I owned a model S with the AP1 system for more than 50,000 miles. I used it all the time and loved it! Once you learn to use it it’s great. I now have a model X with the AP2 system and it sucks! If I could trade this system for the old system I would do it today.

With the old system the camera in the front of the car would read to speed limit signs posted along side the road, and it was very accurate and always up to date because it read current speed limit signs. The new system uses some GPS data and I drove from Alabama to Florida and it almost was never in the correct speed limit mode except when you get on the major highway. The system in existence now is terrible! Also with the old auto pilot system you could do lane changes with the turn signal indicator anywhere. Now you can only do it on major highways. Give me the old system!

    Created 8-Jul-2018
Actually moderator has edited my original post. The AP2 (at least in Europe) does NOT slow down on change of speed downwardly. As edited, it reads as Autopilot does not change the speed upwardly but it does downwardly which is incorrect.

    Created 3-Jul-2018
I have to add that I have been monitoring speed limit change for a while on my display comparing with actual road speed limit and it is really safe to say that it is possible to at least reduce speed of the car to new max speed suggested by GPS then when the speed goes back up again with a single shift of the stick up to go back to the previous higher speed.
    Created 2-Jul-2018
I agree with both above comments but this is the case with other autopilot capability too. As I mentioned it can be overridden by the driver and only used in highways with various speed limits. Or alternatively it can work only when reducing speed. For example if you are driving at max speed of 70 mph or 120 Kmh and GPS shows reduced speed to 50 mph, then the car can slow down.

We already have this function (I believe ) in AP1. Moreover this is one step further to full autonomous driving and I know Tesla is working on it. The idea is to use this function reasonably and responsibly like any other autopilot functions

    Created 1-Jul-2018
I should add that tthe GPS is imperfect too. Sometimes roads with very different speeds are too close and the wrong road is chosen by the system.
    Created 1-Jul-2018
The problem with automatic speed changes is that both the road databases and the sign detection system are imperfect.  So automatic changes might lead to accidents that Tesla might be sued for.
    Created 1-Jul-2018