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TACC does not work very well on curvy roads :(

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No, TACC does not adjust based on speed limit, though you can manually reset the TACC speed to the new limit.
I would have said "semi-automatically" or something. "Manual" to me would mean nudging the speed up or down to meet the limit. Presumably you are talking about the brief tug on the stalk which resets TACC to the detected limit in a single operation.

I'd like it if TACC would drop to a detected reduced limit automatically, though you'd want some sanity-checking on that (say, not more than a 5 mph drop to be done automatically?). I don't think you'd want it to speed up automatically, though again maybe a 5 mph increase would be reasonable. I'd also kind of like it if it would do geofenced learning so it could remember that I always drop or raise the speed at certain points. Maybe with a future update?
 
I'm a bit confused. I'm not expecting the car to "learn" (yet ;)) but I'm surprised you're asserting that it won't "improve with time" despite Tesla's history of and commitment to software updates. Heck, you've offered the Mercedes example of a solution to the problem and are assuming Tesla won't at least meet that standard. Odd.

i agree.

so lets check back in say, 2025. cuz as of 2015, tacc is dangerous as it is exciting.
95% reliability is worth jack if hitting that 5% once is enough to put you in a hospital.

Wow, Hwy 17 seems like a pretty challenging road for TACC, I am impressed that it worked so well for you.

i gather it's the opposite:

the 17 is like a normal hwy.
it's just telling how tacc has not worked well, for such a common scenario.

It seems to me that some people are using cruise control where it shouldn't really be used.

blaming the victim, are we?
:)
 
I see you live in Vancouver. I am going to assume you are not familiar with the Hwy 17 being referred to. I can assure you it is far from "normal". I've driven it many times. It is twisty, steep, and the lanes are narrow with typically no or very little shoulder.

But it is a two-lane (in each direction) limited access freeway with center divider. Not what I would call twisty or steep. Yes, it's unusual *for a freeway* but it's still a freeway. It's no surprise that TACC works fine there.

If you want twisty and steep try Black Bear Pass near Telluride CO (but not in your Tesla :)
 
But it is a two-lane (in each direction) limited access freeway with center divider. Not what I would call twisty or steep. Yes, it's unusual *for a freeway* but it's still a freeway. It's no surprise that TACC works fine there.

If you want twisty and steep try Black Bear Pass near Telluride CO (but not in your Tesla :)

Well, I didn't expect it to work well, and it did. So I guess my perspective is different. Obviously there are plenty of roads more curvy and dangerous, but I wouldn't use TACC on them.
 
If the road is too curvy for TACC to work, the road is too curvy for cruise control in the first place.
From the previous anecdotes, I'm not sure that's the case. I get the impression from those anecdotes that simple slight twists to get around, say mountain terrain, are often enough to throw off TACC.
 
I just used it on highway 17 from Santa Cruz to Los Gatos and it worked flawlessy the whole way, zero intervention from me. Medium heavy traffic, lots of weaving idiots, on a very curvy road, short wall to the left with oncoming traffic. Car distance set to 6 or 7. Starting to wonder if the poor performance people are experiencing is when the following distance is < 6.

I have also done 17 and TACC worked completely flawlessly, even with the typical sudden slow downs.

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It's not your typical freeway. It's a very curvy route up and over a mountain. Two lanes each side and notorious around here for accidents. But a blast to drive. Everybody i know says they're scared of it. I love it!

?? 17 is a FREEWAY. I certainly expect it to work there. I find it works well enough most of the time on real lay twisty roads (think Skyline Dr or Woodside Rd west of Woodside).

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I totally agree on autonomous. I like using it because it stops me from my very bad habit of zeroing in on the car in front of me because they are always going slower than I want. I actually think TACC has slowed me down and made me a more relaxed and polite driver. It's a bad habit that I just can't seem to break. Ironic, I buy a rocket ship of a car and end up driving slower than I did before. Maybe I am finally growing up!

Seriously, any kind of cruise control shouldn't be used on curvy roads. TACC is not autonomous driving.

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Originally Posted by bluenation viewpost-right.png
i gather it's the opposite:

the 17 is like a normal hwy.
it's just telling how tacc has not worked well, for such a common scenario.
:smile:



"Highway 17 is far from normal and it worked fine. Not sure how you are interpreting what I said."

I think we are talking about two different 17s. 17 from San Jose to Santa Cruz is far from a typical US FWY.
 
I totally agree on autonomous. I like using it because it stops me from my very bad habit of zeroing in on the car in front of me because they are always going slower than I want. I actually think TACC has slowed me down and made me a more relaxed and polite driver. It's a bad habit that I just can't seem to break. Ironic, I buy a rocket ship of a car and end up driving slower than I did before. Maybe I am finally growing up!

Yeah I'm having the same experience. If someone cuts in front of me, the car backs off and I don't get angry. I also find not having to modulate the throttle constantly gives me MORE attention to spend on the rest of driving/monitoring other cars.
 
From the previous anecdotes, I'm not sure that's the case. I get the impression from those anecdotes that simple slight twists to get around, say mountain terrain, are often enough to throw off TACC.

Certainly in the case of Highway 17 you are supposed to slow down by 5-10mph around the curves. I would say that isn't an appropriate time for cruise control, since you are constantly slowing down and speeding up. Relying on the car in front of you to slow you down isn't great if they suddenly change lanes coming into the curve. I think the poster you are replying to is saying that if the curve is sharp enough to throw off TACC you would probably have to disable CC to slow down even if there was no car in front of you.
 
Certainly in the case of Highway 17 you are supposed to slow down by 5-10mph around the curves. I would say that isn't an appropriate time for cruise control, since you are constantly slowing down and speeding up. Relying on the car in front of you to slow you down isn't great if they suddenly change lanes coming into the curve. I think the poster you are replying to is saying that if the curve is sharp enough to throw off TACC you would probably have to disable CC to slow down even if there was no car in front of you.

In my case, there was sufficient traffic such that the prevailing speed never exceeded safe curve speed. But your point is taken.
 
But it is a two-lane (in each direction) limited access freeway with center divider. Not what I would call twisty or steep. Yes, it's unusual *for a freeway* but it's still a freeway. It's no surprise that TACC works fine there.
Sorry, maybe you are calling it a "freeway" based on a map you are looking at, but it is not a freeway, the part under discussion that goes over the mountain between Los Gatos and Santa Cruz has multiple intersections that are not the "freeway limited access" type with on ramps and off ramps, and it the lanes are narrow with no shoulder at all for most of it. Not a "freeway". It is notorious for having a higher accident rate.

I am impressed that TACC works well on it.

And yes, it's a fun drive when traffic is light.
 
So I'm new to this forum, but have spent some time on Tesla's forum since getting my P85D in December.

I love my car, but it still amazes me the number of people who respond in the form of "you're holding it wrong" or "the manual says you shouldn't do XXX". I love the TACC. It got even better in 6.2. I use it every day in traffic. On local roads. Yes, I know what the manual says. Yes, the car has "tried to kill me" on several occasions. But that's fine. I am responsible for being in control of my car at all times and supervising the TACC. I accept the responsibility. And the truth is it works amazingly well 90+% of the time in rush hour traffic and it lowers my stress getting home each and every day. I understand how it works. Every time there is an upgrade things change and it's my responsibility to be alert to understand those changes. But: that doesn't change the fact that I want it to improve in these situations and for Tesla to make it better. Those disclaimers aren't because Tesla never wants to have TACC work 24x7 everywhere, it's legal stuff and a statement around where they think it's "nearly bulletproof". I want it to do more, I'm sure Tesla aspires to more, I'll provide feedback to help. I don't think it helps to tell people to only use it "the way the manual says". If you love your car and Tesla, let's help give the data necessary to help them go to the next level. Yes, the car tries to wreck almost every time I go around a corner on TACC and cars are stopped ahead. I'm in control, expect that and prevent that from happening. That doesn't mean I don't want Tesla to eventually fix that. My feedback to them is in the most positive light possible. There is much to improve. 60+% of what I gave feedback on in 6.1 has totally been addressed. I'm happy!