Interesting Observation with TACC

[Alex Van Ness]

My wife and I were driving on the Skyline Drive in Virginia and I noticed something very interesting with TACC. The Skyline Drive is a relatively windy mountain top road with a speed limit of 35mph in the Shenandoah National Park. I set TACC to 40mph and as we went around sharp curves, the TACC would slow the car down to the proper speed to go around the curve just before it entered the turn (usually to 30-35mph). At first, I though it was a mistake with TACC, but it happened around every curve where 40mph would have been a little too fast. Has anyone else experienced this? Does anyone know if TACC has always done this? Does it use GPS to judge the proper speed for the upcoming curve? I'm just curious about it so any info would be great.

 

[gavine]

Does your car have Autopilot?

 

[Todd Burch]

It's been doing it for awhile, and most speculate that it is indeed GPS combined with mapping to determine upcoming curves.

 

[S4WRXTTCS]

My understanding is it didn't used to do it when the feature was first released. But, then it was added to it during some 7.X version.

Some people love the feature, and other people wish they could turn it off.

Personally I'd prefer to turn it of, but I haven't had any bad experiences with it. I do use the throttle to bring it back up to a proper corning speed (10 over the speed limit). I don't want to drive like an old grandma through the corner.

 

[Alex Van Ness]

Does your car have Autopilot?

Yes it does. It's a late 2015 S85D.

 

[Todd Burch]

I wouldn't say it's as slow as grandma, but certainly it's slower than a typical human would take the curve.

But on the other hand, it's probably as fast as you'd want to let autopilot take the curve in its current iteration.

 

[DillyBop]

My wife and I were driving on the Skyline Drive in Virginia and I noticed something very interesting with TACC. The Skyline Drive is a relatively windy mountain top road with a speed limit of 35mph in the Shenandoah National Park. I set TACC to 40mph and as we went around sharp curves, the TACC would slow the car down to the proper speed to go around the curve just before it entered the turn (usually to 30-35mph).

I noticed the same thing on the same highway a couple months ago!

I was impressed with its performance. very smooth and didn't slow down TOO much.

 

[rhumbliner]

I recently tested the TACC on the Pacific Coast Highway and my experience has been roughly the same. It might be my imagination but I think it did a better job of slowing thru the curve when the big, yellow > > > signs bracket the curve.

I have AP but don't trust it on curvy, 2-lane roads with heavy traffic. Too often it would exhibit the "lurch" toward oncoming traffic that a few others here have reported.

 

[Alex Van Ness]

I recently tested the TACC on the Pacific Coast Highway and my experience has been roughly the same. It might be my imagination but I think it did a better job of slowing thru the curve when the big, yellow > > > signs bracket the curve.

I have AP but don't trust it on curvy, 2-lane roads with heavy traffic. Too often it would exhibit the "lurch" toward oncoming traffic that a few others here have reported.

I completely agree. I did not have auto pilot on. I tried it for about 2 minutes and realized it could not handle the curvy road.