Why isn't it possible to set cruise control to follow speed limit?

[stevezzzz]

Here's where the confusion lies: the pull-stalk-and-hold action has different meanings depending on context. There are several cases, but two will illustrate the problem.

Case 1: TACC is engaged and is holding the current set speed (the triangular bug on the speedo). If the solid or dotted tick mark representing the speed-limit-plus-offset is displayed at any speed other than the current set speed, pull-and-hold resets the current set speed to the new speed, and the car accelerates or decelerates to the new set speed.

Case 2: TACC is disengaged and the driver controls the car's speed with the go pedal; the triangular bug and the tick mark are displayed at two different speeds. Pull-and-hold does not reset the current set speed to the speed-limit-plus-offset (tick mark), but instead re-engages TACC at the 'old' set speed (triangular bug).

Why Tesla implemented this modal behavior is unknown, and frustrating to me. What happens frequently is that I disengage TACC with braking (as at a traffic light), then encounter a change in the speed limit and watch the tick mark move in response, and attempt to use pull-and-hold to re-engage TACC at the tick mark (as in Case 1) only to realize it's accelerating to the old set speed instead.

 

[Cyclone]

Steve, in your scenario at the bottom, what happens if you pull and hold towards you? Would that change the cruise speed to the current speed limit + offset? So perhaps the engagement process would be not to flick the lever towards toward (or press the go pedal), but pull and hold the level towards you to reset to current limit + offset.

 

[ArtInCT]

Sometimes it's best to just put the coffee down and step away from the thread for a while.

Boy, do I agree with this.... sheesh.

 

[Andyw2100]

First you said this:

to be clear from the confusion above: there is a way to set the car to drive at the speed limit.

If you want to set the car to drive at the speed limit: pull back towards you and hold briefly to set the cruise to follow the speed limit (make sure the offset is at zero)

and I showed clearly why that was wrong, with documentation from the manual, which I had also supplied before.

Then you attempted to say I was wrong, but slightly changed what you were saying, by writing:

The speed assist absolutely does change the set speed based on changing speed limits. You can see the little tick mark change change as it registers the new speed limit. If you agree with the new speed limit you simply pull the lever back and the car follows the new speed limit.

Sometimes you won't agree with the new speed because it read the sign from an exit or other adjoining road so it is reasonable to require that you confirm the new set speed. But it absolutely does follow and adjust the set speed to changing speed limits.

I really can't tell if you are just being argumentative at this point, refusing to just admit that you were wrong, or if you really can't see the difference between what you are saying and what the reality is. I think you do "get it" because later in this thread you seem to, and you kind of make reference to it here when you talk about "require that you confirm."

The point is that the "Speed Assist" speed is the one that is being adjusted in the way you describe, not the cruise control speed. The cruise control speed can be matched to the Speed Assist speed by pulling the lever, as you describe. But, and this is the important part, so I'm going to write it all in caps, so you don't miss it again, because you've missed it a few times before, THE CRUISE CONTROL SPEED WON'T CHANGE ON ITS OWN WHEN THE SPEED ASSIST SPEED CHANGES. THE CAR CAN NOT FOLLOW THE SPEED LIMIT AS THE SPEED LIMIT CHANGES.

I think you understand this, because you do talk about having to reset the cruise speed, by pulling the lever towards you. What I don't understand is how you can refer to that as "following the speed limit." The car isn't following anything. You are resetting the cruise control speed to the Speed Assist speed repeatedly. The car isn't following anything on its own, which was the original question. Yes, the car "knows" the speed limit at any time, and yes, you can set the cruise control speed to that speed at any time, but no, the car can not do this on its own.

- - - Updated - - -

Sometimes it's best to just put the coffee down and step away from the thread for a while.

Boy, do I agree with this.... sheesh.

i can't help but think that those comments were directed at me, and my somewhat vigorous and pointed discussion on this topic. If so, in my defense let me say that I can't help but feel strongly about something when I have taken the time to post the correct information, with excerpts from the manuals and release notes to support the information I am providing, only to then have someone else incorrectly post that the information I provided is wrong. I'm sorry, but I'm going to react pretty strongly to that.

 

[ecarfan]

Yes, and I believe the video posted up thread by cgiGuy confirms what Andyw2100 is describing. With TACC engaged the car's speed will not change automatically when the posted speed limit changes but the driver can "tell" the car to change the TACC speed to the current posted speed by pulling the lever towards the driver.

I do not own a post-September 2014 Model S so cannot confirm that behavior directly but I believe that is what the posted video shows.

If I don't have that correct, please inform me.

 

[Andyw2100]

bhzmark, I agree with your statement, but that still isn't "automatic" as asked in the opening post or demonstrated prior to production.

Yes, and I believe the video posted up thread by cgiGuy confirms what Andyw2100 is describing. With TACC engaged the car's speed will not change automatically when the posted speed limit changes but the driver can "tell" the car to change the TACC speed to the current posted speed by pulling the lever towards the driver.

Cyclone, ecarfan (and I expect most of you) understand what I've been saying.

Thanks, Cyclone and ecarfan!

 

[stevezzzz]

Steve, in your scenario at the bottom, what happens if you pull and hold towards you? Would that change the cruise speed to the current speed limit + offset? So perhaps the engagement process would be not to flick the lever towards toward (or press the go pedal), but pull and hold the level towards you to reset to current limit + offset.

No, it won't. That's precisely the issue: when TACC is currently disengaged you can pull and hold the lever till the cows come home, and it won't update the set speed, but performs a Resume instead. Conversely, when TACC is already engaged, pull-and-hold performs the Update function (i.e., updates the set speed to reflect the speed-limit-plus-offset value).

So one available driver action (pull-and-release the stalk) always performs a Resume. The other driver action (pull-and-hold the stalk) is either Update or Resume, depending on context.

 

[Cyclone]

Steve, thanks for the update. I agree that I confusing. It's easy when you know what is happening, but from standpoint of not knowing, the difference in behavior is confusing. Hopefully a near-future release will streamline things.

 

[cgiGuy]

And of course, these videos are the reason all of us assumed this behavior was already part of TACC: [video]https://youtu.be/7quu551ehc0?t=49s[/video]

I'm sorry, but I'm going to react pretty strongly to that.

I really don't know what's hard to understand about this.

I'll try one more time.

In other words YOU CAN NOT HAVE THE CRUISE SET SPEED FOLLOW THE POSTED LIMIT. No. Just no.

Reacting strongly and helping is one thing. Reacting strongly and being insulting is another. Would you speak that way to someone's face if you were trying to help them understand and they weren't getting it?

 

[Andyw2100]

And of course, these videos are the reason all of us assumed this behavior was already part of TACC: [video]https://youtu.be/7quu551ehc0?t=49s[/video]

The poster you claim I'm insulting has a car with TACC functionality. He doesn't need to watch a video to assume anything.

Reacting strongly and helping is one thing. Reacting strongly and being insulting is another. Would you speak that way to someone's face if you were trying to help them understand and they weren't getting it?

First of all, I don't think I was particularly insulting. Saying things like, "why are you being so stupid?" or "you must be dumber than dirt not to understand this" would be insulting. My comments were somewhat on the sarcastic, and perhaps even condescending side, but I think they were appropriate for someone who was a) taking a similar tone with me, and b) WAS WRONG when I had provided proof that I was right.

As for your question as to whether or not I would speak that way to someone's face, I actually would. I'm not afraid of confrontation and standing up for myself when I know I'm right. That occasionally embarrasses people I'm with so I try to be conscious of that.

I want to get this posted, but I'll write up an example of my confrontational nature, Tesla-related, that took place a couple of weeks ago and post it as a follow up.

 

[Andyw2100]

I want to get this posted, but I'll write up an example of my confrontational nature, Tesla-related, that took place a couple of weeks ago and post it as a follow up.

I had gone to a touchless car wash, to get my P85D washed. I had previously purchased $100 worth of washes at this place for $50, and had a card that had a remaining credit on it, good at a number of locations, only two of which are near locations I would travel. After carefully maneuvering around big tracks of ice, and walking up to the machine to pay for my wash, I couldn't get it to accept my card. To make a long story short, I wound up having to back out and let a guy in a truck behind me try to use his credit card, and it turned out the card acceptor just wasn't working to read any cards at all.

I went into the convenience store associated with this car wash to see if there was a way the person working the register could manually take a charge off the card, and print a ticket that would allow me to operate the machine and generate a wash. There wasn't. I told the young woman working the register that I'd like to leave my name and number so that I could call and speak to the manager during the week. (This was on a Saturday.) I was completely polite, and not at all angry with the person at the register. My plan was to a) make sure someone in charge new their system wasn't functioning, and b) probably ask for a free wash credit for the inconvenience of having made a trip there without being able to get a wash. (I could have paid cash for the wash, but that would have had me paying double what the washes cost me.) The woman handed me a paper and pen and I started to write my information, but immediately realized there was someone behind me waiting to check out, so I moved over to an unoccupied register, so that he could check out. I started writing my information there, and heard him say to the young woman, loudly enough for me to hear, "Some people are such pains in the ass. I could never have a job like yours."

Before I continue I should say that I am, as far as physical confrontation goes, a wimp. I have not been in a fight since sixth grade, and I lost that fight badly. The guy that made the comment was much bigger than me, and looked like he very possibly may have been arrested at some point in his life for beating up people like me.

I realize most people in the world would have let that comment pass, without respect for what the other guy looked like, and certainly would have knowing that a comment could put them in very real physical danger. But I didn't care. I stopped writing, looked up, looked directly at him, and said, "Excuse me?" He didn't say anything, and wouldn't look at me. So I continued. I said, "I wasn't in any way rude or mean to this woman. I simply asked to leave my name and number for her manager." He still didn't say anything as he was finishing his transaction, thanked the woman, and left. I then went back to her register, somewhat dumbfounded, and asked her if she thought I had been in any way difficult or rude. She said that I absolutely had not been, and that the guy had been in several times already that day, and that she thinks he was just looking for an excuse to have something to say to her. She said not to worry about it at all.

My point is that when I know I'm right I'm not afraid to say so, even at the risk of getting punched in the face.

I really don't think using all caps (or even being a little condescending) when someone keeps saying I'm wrong, after I've proven I'm right, (with documentation to support my points), is over the top or even out of line. If you do, cgiGuy, then I guess we'll just have to agree to disagree.

 

[Torpedo Ted]

No, it won't. That's precisely the issue: when TACC is currently disengaged you can pull and hold the lever till the cows come home, and it won't update the set speed, but performs a Resume instead. Conversely, when TACC is already engaged, pull-and-hold performs the Update function (i.e., updates the set speed to reflect the speed-limit-plus-offset value).

So one available driver action (pull-and-release the stalk) always performs a Resume. The other driver action (pull-and-hold the stalk) is either Update or Resume, depending on context.

You are correct. Pull and hold to set to speed limit only works if TACC is already engaged. This is very confusing and annoying

 

[CHG-ON]

You are correct. Pull and hold to set to speed limit only works if TACC is already engaged. This is very confusing and annoying

Agreed. Took me a few tries to figure out it's logic. I don't get it. I would think that when initially setting the cruise, the option to default to the speed assist limit would make the most sense , along with the ability to set at current speed with a quick tap.

 

[bhzmark]

Thread question: " Why isn't it possible to set cruise control to follow speed limit?"

Answer 1:you can NOT set the car to adjust the car speed up and down automatically to follow the speed limit in the same way it adjusts its speed up and down automatically to follow the car in front of it.

Answer 2: you CAN set the car's cruise control system to follow the speed limit. And cruise system follows the speed limit by indicating its determined speed limit (and confidence level thereof) with the tick mark (solid or dashed) on the speedo. If you then want the car to adjust its actual max speed to the new speed limit, you simply pull and hold back the lever and car speed will adjust to the new speed limit speed.

I think it is reasonable that the car does not automatically adjust the max cruise speed upwards when it registers a higher speed limit -- because I have seen firsthand that it sometimes gets that wrong. So asking for driver confirmation to increase the speed seems a reasonable input. I suppose adjusting it downward without add'l driver input would ok in most cases.

Asking for driver input to resume cruising after a stop at a light when the car in front moves ahead (or perhaps makes a rt turn while the light is still red!) seems reasonable also.

Some may wish to avoid that input. Perhaps when the confidence level of detected speed limits is increased (perhaps maps encoded with the speed limit) that will happen. Just reading signs doesn't seem to be enough.

 

[Andyw2100]

Thread question: " Why isn't it possible to set cruise control to follow speed limit?"

Answer 1:you can NOT set the car to adjust the car speed up and down automatically to follow the speed limit in the same way it adjusts its speed up and down automatically to follow the car in front of it.

Answer 2: you CAN set the car's cruise control system to follow the speed limit. And cruise system follows the speed limit by indicating its determined speed limit (and confidence level thereof) with the tick mark (solid or dashed) on the speedo. If you then want the car to adjust its actual max speed to the new speed limit, you simply pull and hold back the lever and car speed will adjust to the new speed limit speed.

I'm done.

I would ask that someone please take my place in trying to explain to bhzmark that he or she is just wrong. I don't want to risk insulting him or her any more, I don't want to be condescending, and perhaps most importantly, I don't want my head to explode. So I'm done. You guys can have at it or not.

 

[Danal]

Here's where the confusion lies: the pull-stalk-and-hold action has different meanings depending on context. There are several cases, but two will illustrate the problem.

Case 1: TACC is engaged and is holding the current set speed (the triangular bug on the speedo). If the solid or dotted tick mark representing the speed-limit-plus-offset is displayed at any speed other than the current set speed, pull-and-hold resets the current set speed to the new speed, and the car accelerates or decelerates to the new set speed.

Case 2: TACC is disengaged and the driver controls the car's speed with the go pedal; the triangular bug and the tick mark are displayed at two different speeds. Pull-and-hold does not reset the current set speed to the speed-limit-plus-offset (tick mark), but instead re-engages TACC at the 'old' set speed (triangular bug).

Why Tesla implemented this modal behavior is unknown, and frustrating to me. What happens frequently is that I disengage TACC with braking (as at a traffic light), then encounter a change in the speed limit and watch the tick mark move in response, and attempt to use pull-and-hold to re-engage TACC at the tick mark (as in Case 1) only to realize it's accelerating to the old set speed instead.

I also find this very annoying, and slightly dangerous. If Tesla monitors these forums: Please consider changing this to a consistent behavior. Almost anything would be OK, as long as it is not modal/context dependent.

 

[Sigma4Life]

Thread question: " Why isn't it possible to set cruise control to follow speed limit?"

Answer 1:you can NOT set the car to adjust the car speed up and down automatically to follow the speed limit in the same way it adjusts its speed up and down automatically to follow the car in front of it.

Answer 2: you CAN set the car's cruise control system to follow the speed limit. And cruise system follows the speed limit by indicating its determined speed limit (and confidence level thereof) with the tick mark (solid or dashed) on the speedo. If you then want the car to adjust its actual max speed to the new speed limit, you simply pull and hold back the lever and car speed will adjust to the new speed limit speed.

I think it is reasonable that the car does not automatically adjust the max cruise speed upwards when it registers a higher speed limit -- because I have seen firsthand that it sometimes gets that wrong. So asking for driver confirmation to increase the speed seems a reasonable input. I suppose adjusting it downward without add'l driver input would ok in most cases.

Asking for driver input to resume cruising after a stop at a light when the car in front moves ahead (or perhaps makes a rt turn while the light is still red!) seems reasonable also.

Some may wish to avoid that input. Perhaps when the confidence level of detected speed limits is increased (perhaps maps encoded with the speed limit) that will happen. Just reading signs doesn't seem to be enough.

I'm done.

I would ask that someone please take my place in trying to explain to bhzmark that he or she is just wrong. I don't want to risk insulting him or her any more, I don't want to be condescending, and perhaps most importantly, I don't want my head to explode. So I'm done. You guys can have at it or not.

Andyw2100 I don't understand why you are still upset. bhzmark clearly says that the car does not automatically change speeds to match the speed limit in 'Answer 1'. He then states you can manually tell the car to follow the speed limit in 'Answer 2'. He then goes on further to give his opinion. I understand he may have upset you previously, but now it seems like your simply holding a grudge and it's you that's no longer being logical. That's just my 2 cents.

 

[Andyw2100]

Andyw2100 I don't understand why you are still upset. bhzmark clearly says that the car does not automatically change speeds to match the speed limit in 'Answer 1'. He then states you can manually tell the car to follow the speed limit in 'Answer 2'. He then goes on further to give his opinion. I understand he may have upset you previously, but now it seems like your simply holding a grudge and it's you that's no longer being logical. That's just my 2 cents.

It's the first part of his "Answer 2." That's just not correct. He wrote: "Answer 2: you CAN set the car's cruise control system to follow the speed limit."

You can't. And saying "you can" could easily confuse people. We've seen people here confused in the past over far less confusing things than this. That's what I'm trying to prevent.

 

[Sigma4Life]

It's the first part of his "Answer 2." That's just not correct. He wrote: "Answer 2: you CAN set the car's cruise control system to follow the speed limit."

You can't. And saying "you can" could easily confuse people. We've seen people here confused in the past over far less confusing things than this. That's what I'm trying to prevent.

I see what you're saying. I agree that it could be worded more clearly as it does seem to imply that the car will make speed limit adjustments without additional input.

 

[Andyw2100]

I see what you're saying. I agree that it could be worded more clearly as it does seem to imply that the car will make speed limit adjustments without additional input.

Thanks for saying that. And what's frustrating for me is that I honestly think that I have explained it about as well as it can be explained, with references, so that it would be clear, and there wouldn't be confusion. But bhzmark keeps coming back and muddying the waters. At this point I don't really care whether or not he or she fully understands how it works. I honestly think he or she does, and is just saying things differently. But to let those posts stand, without addressing them, as if they are correct could potentially confuse someone else. And now I guess I kind of feel like "in for a dime, in for a dollar" on this.