TACC Adjust for Local Speed Limit


Now Implemented!


Have TACC automatically adjust to the current speed limit, with an adjustment for setting miles above/below that limit.


Currently, the Model S recognizes the speed limit, and equipped Model S can take into account the driver’s offset for cruise control setting and set the cruise accordingly if the cruise stalk is pulled toward the driver and held for a couple of seconds. However, it will not adjust to new speed limits that are identified. You must pull the cruise stalk toward you again to set the cruise to the new speed limit.


Implemented in 2016 for cars with HW2.0 or later as map-based.  Upgrade in 2020 as vision-based (i.e. reads the actual speed limit signs).

lightly edited by moderator
Category: Y3XS Applies to:
     Created 6-Oct-2015


Please do not enforce this, let it be optional. Cruise control is useless if overriding my speed choice.

I would also like to have an option for Autosteer to also use my speed and not what it thinks is correct. It should also always start with the current speed and not jump up or down to what it believes is correct.
    Created 27-May-2020
This is already implemented.
    Created 1-Sep-2016
A feature with both + and -; I'm inclined to devote resources to other ideas, given the availability of +/- 5mph with but a stalk click.
    Created 1-Nov-2015
I agree with Enji-Benjy although I would make the actual 'change of speed' always a choice rather than purely automatic.
    Created 1-Nov-2015
This is a good idea; a small confirmation warning before it does anything would allay most of JanosB's fears, I think?
    Created 1-Nov-2015
Issue with this is that neither the maps nor the camera processing are anywhere near accurate enough to rely on the speed limits.

As it is, there are several sections where the speed limit dives from the (actual) highway speed of 70kmh to (in extreme examples) 30 kmh.   If the car suddenly slows down on the highway it would be a collision hazard for the car behind ... even if they are ultimately found responsible for an rear-end shunt you don't want to have to go through the process of dealing with the collision and then defending a claim for repairs.  It also has a tendency of reading the speed limit that applies to a slip road even when you're continuing on the main highway, especially when driving (correctly) in the slow lane.

All that plus the effect of poor light conditions / partially obscured speed signs / the cars' position towards the left or right of the carriageway all combine to make the car not at all ready for automatic speed change yet.

Fix all that to get accurately reliable speed limit settings - and I'll vote for this in a heartbeat.  It's not unreasonable: it will be one of the outcomes of the new crowd-sourced mapping data.
    Created 25-Oct-2015
Tesla says that this is coming in 7.0.
    Created 7-Oct-2015