Interesting TACC Behavior

Interesting TACC Behavior

2015 Model S (CPO) 85D -- was driving local 2-lane roads here in MI yesterday with TACC engaged (I have a lead foot). TACC was set at 60MPH (speed limit is 55MPH). Road was mostly straight but there were a few s-curves. Surprisingly to me, TACC dropped the speed from 60 down to about 45 as it entered the s-curve and then as it came out of the curve, resumed set speed. Surprised me and am curious as to how it knew to do that. Software 2018.50.6 here. | 12. März 2019

Been doing that for 6 months or so (for me). Not sure if it is visual detection of the curve via the camera or GPS database knowledge of an upcoming curve. I suspect the latter.

Bighorn | 12. März 2019

Some people have said their car slows appropriately for curves, but you couldn't have proved it by me. Hopefully this is rolling out.

DRFLGD | 12. März 2019

Yeah it's been doing that for me as well for several months.

nothotpocket | 12. März 2019

That's really cool, I haven't noticed that yet on my 2015.

TripleTrucker | 12. März 2019

I thought it would when I tried it several weeks ago. It headed for a tight s curve and showed no signs of slowing, so I bailed! I'll try again and see. | 12. März 2019

My 2014 P85D has been slowing at tight curves with TACC engaged for at least a year or two. It will usually slow to a speed far slower than I would if I were controlling the speed.

pgkevet | 12. März 2019

Things may be different with UK software but interesting that with autosteer enabled on my country 2-lane roads (a game I don't play often and not with other traffic about) then if I have the speed at the legal 60mph +5 it'll often go into a tight bend and then drop out and leave the driver to sort it - not a game to play often. However If i have the speed set to max 50mph it'll slow down and take the same corner.
That implies it's not GPS but looking ahead - just not far enough and computing fast enough?

bryan.hopkins | 12. März 2019

Whether it is camera or GPS, pretty interesting that even on an "older" car, it can do that. I continue to be amazed at these cars.

barrykmd | 12. März 2019

I use TACC frequently on some curvy canyon roads and it's been slowing down on sharp curves for at least a year, if not longer (2015 85D).

On the down side, it's been probably 2 years since Tesla released the AP display (V7?) with the toy car and road viewon the IC. They still haven't calibrated the sensors that "see" the car in front with the optical camera that sees the lane lines. On those sharp curves, the car in front of me veers far outside the lane on the display, but is well within the lane looking out the windshield.

JPPTM | 12. März 2019

Tesla has been accumulating real world driving data for years. It knows what the average/max/min speeds are being driven over many, many roads and routes. It determined that the S curve you were speeding into would be better and safer managed at a lower speed, calculated from the data. GPS and full bidirectional telematics and communication.

terry_and_bonnie | 21. Mai 2019

We have a Model 3 in France and have noticed the TACC will usually slow down appropriately at bends in the road. France doesn’t constantly post speed limits based on road configuration. Basically rural roads are assumed to be 80 km/hr speed limit and bends often need to be taken slower (at least in my brain). The car generally seems to “see” the bend as witnessed by the faint lane marks on the display which show the bends generally. We do not know if our driver actions are being learned or not. Certainly French Teslas are still few. We anxiously await the car’s learning to deal with round-a-bouts and the much dreaded “Priority À droite” rule which gives right of way to traffic from your right, even if their road is minor looking.