Cruise control adapting to speed limits

Cruise control adapting to speed limits

I have a questions for the other model 3 owners about using cruise control. My understanding was that cruise would automatically reduce or increase speed depending on the speed limit and whatever offset you may have chosen. You didn’t have to touch the speed limit button on the screen.

That has happened exactly twice for me (both times, I went from a 70 mph limit to a 55 mph speed limit). Weird that it has happened twice, but never any other time. Is cruise control speed limit adjust supposed to happen automatically, or did I just dream that up? Thanks for any advice!


barb@duke | May 30, 2019

Ours will consistently adjust to speed limit signs (plus the offset) when on autopilot.

BuffaloBillsFan | May 30, 2019

Aaah . . . There’s the rub! I thought it would automatically adjust on just adaptive cruise control as well. Tanks for the input!

rwade2666 | May 30, 2019

if the offset isn't indicated but the speed limit is correct just touch the speed limit sign and the offset will update.

EVRider | May 31, 2019

TACC does not adjust your speed based on speed limit changes, and Autosteer doesn’t either if you’re on a limited access highway. If the car doesn’t think you’re on a limited access highway, Autosteer will be limited to the speed limit plus speed offset (up to a maximum of 5mph) and will adjust your speed accordingly.

walnotr | May 31, 2019

I sadly haven’t haven’t been able to drive my car for a couple of weeks, but have noticed more instances of the speed adjusting on both TACC and autosteer/NoA. What I can’t remember at this time is if it was only on controlled access roads or on some surface streets as well. I tend to use it as much as possible hoping to be part of the solution to FSD so my experiences maybe a little blurred in my not so young brain. I do recall one instance of the car slowing as it approached a lower speed limit sign and was pleasantly surprised when it happened.

cafutter | May 31, 2019

Be aware, the speed limit it thinks is correct, is sometimes incorrect. My experience is near the Maryland -DC line on my way to work. My car thought the speed limit was 25 mph when in fact is was 35 mph. I reported it several times as a bug report and eventually it corrected (whether or not it was because of my I my reporting, is unclear).

CharleyBC | May 31, 2019

I have noticed the set speed reduce, but only when using Autosteer, not just TACC. And “notice” is pretty conspicuous, as it puts a message on the screen about 5 above the limit for Autosteer.

As @cafutter said, it’s annoying when the speed limit data are wrong. It forces you to choose to continue to use Autosteer while driving below the limit, or disengage Autosteer and go your desired speed. (“Bug report: posted speed is 65. Car thinks 55.”)

Techy James | May 31, 2019

@CharleyBC, I agree it's annoying when the Posted Speed Limit and the Map Data Speed Limit don't match, but this will always be a problem until the Camera Recognition is able to identify Street signs. What I find funny about the Map Data, is on one side of the street the data will be off, but when your going other way the map data is correct.
As for the part about using AP or not because the Speed limit, I only noticed AP being affected is if the road is not a Limited Access Road. On Limited Access Roads/Highways I have never noticed it adjusting the speed automatically except occasionally in cases where the road has a hard curve, then it slows for the curve then speeds back up after out of the curve. Now on Limited Access Roads, then AP is limited to 5 over the expected Posted Speed Limit.

BuffaloBillsFan | May 31, 2019

Thanks for the feedback everyone.