Adaptive Cruise Control (experience post FW v6.1)

[drsaab]

I think it's worth reiterating the most surprising behavior I've encountered so far when tacc is engaged; that is, if a car in front of you in your lane is stopped at a signal, the tacc doesn't seem to register it as a target to be tracked and avoided unless it locks on before the car ahead comes to a complete stop. If that car is still creeping even a little bit, no problem: tacc acquires and reacts to it, even if it's a bit later than I would prefer.

Yes. It seems to track and stop below 40mph to 45mph for a stopped car. Above that it does not stop for a stopped vehicle.

Another dangerous situation is where the car in front you are locked on decides to turn left and once it leaves your lane, Tacc may not lock on the new stopped car now in your lane and actually accelerate towards it vs slowing down.

 

[Burt Court]

I think R2B followed the old proverb: When all else fails, read the instructions. That was a great reminder, I've only used one half the potential of my new cruise control. Need to spend more time in my garage, reading.
old geezer

 

[wk057]

So far TACC has been fun. I did some more driving with it on a ~5 lane road (two lanes on each side with a center turn lane).

Any time I was in the left lane following someone using the TACC, and they signaled left, changed to the center lane, and slowed down for their turn, the TACC would basically still have me following them and would slow me down to match until it got very close. Usually I would have to override it and accelerate if someone was behind me since my behavior would make no sense otherwise...

 

[randompersonx]

Another odd behavior I noticed. On the highway if a car in front of me changes out of my lane, and all of a sudden there is nobody in front of me, the car momentarily slows down before speeding up. This behavior is very unusual and certainly annoys people behind me.

 

[jerry33]

Another odd behavior I noticed. On the highway if a car in front of me changes out of my lane, and all of a sudden there is nobody in front of me, the car momentarily slows down before speeding up. This behavior is very unusual and certainly annoys people behind me.

They obviously programmed it to behave like real drivers. Generally when someone passes their first action is to press on the brake pedal (freeway driving here, not passing on a two lane road). Kind of makes you wonder why they bothered to pass.

 

[Saghost]

Another odd behavior I noticed. On the highway if a car in front of me changes out of my lane, and all of a sudden there is nobody in front of me, the car momentarily slows down before speeding up. This behavior is very unusual and certainly annoys people behind me.

Is the car that was in front of you that changed lanes slowing down? If so, it might be the same thing wk057 is reporting - a tendency to think the car it's locked on to is still in front of you even though it has moved out of your path slightly.

Unless you cross-reference the radar to the lane lines, it'll be tough to separate cars that just moved out of your lane from curves that happen to your lane. Maybe Tesla hasn't hooked the two together in the computer's head yet (but they will have to do some of that when autopilot starts steering anyway, so I'd expect this tendency to improve in a future update.)
Walter

 

[randompersonx]

Is the car that was in front of you that changed lanes slowing down? If so, it might be the same thing wk057 is reporting - a tendency to think the car it's locked on to is still in front of you even though it has moved out of your path slightly.

Unless you cross-reference the radar to the lane lines, it'll be tough to separate cars that just moved out of your lane from curves that happen to your lane. Maybe Tesla hasn't hooked the two together in the computer's head yet (but they will have to do some of that when autopilot starts steering anyway, so I'd expect this tendency to improve in a future update.)
Walter

I've had this happen several times where the car in front of me is not slowing down, but just gets out of my way and maintains their speed in the lane to my right.

It doesn't happen if they change out of my lane and there is another car still in the range of the Radar in front of me.

 

[wk057]

I've had this happen several times where the car in front of me is not slowing down, but just gets out of my way and maintains their speed in the lane to my right.

It doesn't happen if they change out of my lane and there is another car still in the range of the Radar in front of me.

I think the car continues to track the car that was in front of you in this instance, same thing as my post above about the center turn lane.

I did some more driving tonight. First time my fiance has been in my car since I got the TACC update. Freaked her out a bit.

I will note that the TACC locking on to a stopped vehicle in front when it has not been locked on to anything for a bit (no cars immediately ahead) is hit or miss. A few times it locked on and started to slow and came to a stop, and a few times it definitely wasn't going to and I stopped manually. So, careful with that. Obviously always pay attention to what it's doing.

 

[randompersonx]

I did some more driving tonight. First time my fiance has been in my car since I got the TACC update. Freaked her out a bit.

Interestingly, my wife commented on how other than my mentioning "this is not me ... this is all the car", she found it very difficult to tell when I was in TACC and when I was driving myself in MOST scenarios (though there were a few cases where the car was obviously misbehaving).

 

[wk057]

Interestingly, my wife commented on how other than my mentioning "this is not me ... this is all the car", she found it very difficult to tell when I was in TACC and when I was driving myself in MOST scenarios (though there were a few cases where the car was obviously misbehaving).

She kept looking at my feet, then freaking out. lol. "Oh my God the brake pedal moved..."

 

[randompersonx]

She kept looking at my feet, then freaking out. lol. "Oh my God the brake pedal moved..."

The pedals move on their own? This is going to start a new stream of fascination.

 

[Todd Burch]

Based on steering wheel position, speed, and the position of the radar target, it should be pretty easy to determine if the car it's tracking is in your path or an adjacent lane. If the car is slowing down when the car is in the adjacent lane, then it sounds like TACC needs a little bit more work...but I'll take it in its current state for now!

We probably just need to be a little extra vigilant until it improves. (Should be vigilant anyway anytime some dumb computer is doing the driving for us .

 

[EarlyAdopter]

The pedals move on their own? This is going to start a new stream of fascination.

Not to kill the excitement, because it is indeed cool, but my wife's two year old Volvo with TACC does the same (moves the pedals).

One thing from our experience with her car is these systems would be better called "active following systems" to emphasize the need to have a car in front of you to lock onto to function correctly.

Car in front of you that you've locked onto slows down and stops? No problem. The system will follow.
Car way out ahead of you, outside of radar lock range, already stopped? Problem. The system may or may not lock on in time to stop you.
Car in front of you moves a lane over and there's no other car within in range directly in front of you to acquire a new lock? Problem. The system may continue to follow the car now in the other lane because it wants to maintain a lock on something.

 

[wk057]

The pedals move on their own? This is going to start a new stream of fascination.

Only the brake pedal, the accelerator doesn't move. It is an odd sensation when the car pulls the brake pedal from under my foot. (I've been at the ready during stops just in case.)

 

[Boeing777]

A couple more observations about 6.1 and tacc in my P85D.

- Normal cruise control (non-tacc) may now be set as low as 18 mph.

- WARNING: When you allow tacc to bring the car to a dead stop in traffic, don't forget that it's still armed: if you're the second car in line at a stop and the car ahead of you makes a right turn, you can't just ease forward to the stop line (creep OFF) because tacc will assume you want to resume traveling at speed as soon as you touch the accelerator. Surprised the heck out of me, though on reflection I should have been able to predict the behavior.

This is the first circumstance in which I've ever thought creep might be a good thing. :biggrin:

This is an excellent observation, and one that I've already encountered as well. As you know, the system will go to HOLD after a few seconds requiring a light push on the pedal to re-engage. The only time the ACC will engage and accelerate after a complete stop (without driver intervention) is when the vehicle in front starts moving almost immediately after stopping. In that case, the ACC stays engaged, and does not have a chance to revert to the HOLD mode.

 

[evboost]

This is an excellent observation, and one that I've already encountered as well. As you know, the system will go to HOLD after a few seconds requiring a light push on the pedal to re-engage. The only time the ACC will engage and accelerate after a complete stop (without driver intervention) is when the vehicle in front starts moving almost immediately after stopping. In that case, the ACC stays engaged, and does not have a chance to revert to the HOLD mode.

It may have been noted below as well, but another couple of observations I have to add:

- At this point I after running my commute with and without TACC in nearly identical conditions, I find its about a wash on efficiency.
- Seems to do OK on curves for me. Specifically freeway off/on ramps. I had the car in front of me switch to a different lane and TACC didn't send me to full speed.
- Things that can confuse the system: Big rig trucks, overpass shadows, lane merges where you have to "zipper". The first two seem to over stimulate the system a bit. The later one needs a human touch yet, though the collision avoidance really is happy to tell me about almost hitting something.

Cannot wait until lane holding arrives to continue the journey of autopilot.

 

[Cottonwood]

I would like for the 6 and 7 distances to be noticeably larger. When I am doing a long drive on wide open, empty highways, a few hundred meters more distance is desirable. The 7 setting at 70 mph should be towards the limits of the reliable radar range, but close enough that the radar tracking can still work well and distances greater than the desired trail distance can be measured.

 

[NOLA_Mike]

I also note that the distances are not the same for every speed. 1 or 2 follows much closer to the vehicle in front at 35 MPH than it does at 75 MPH. Makes sense since following too close at high speeds would be dangerous and not allow enough room for safe stopping in all situations.

 

[Cottonwood]

I also note that the distances are not the same for every speed. 1 or 2 follows much closer to the vehicle in front at 35 MPH than it does at 75 MPH. Makes sense since following too close at high speeds would be dangerous and not allow enough room for safe stopping in all situations.

I agree that the distances are larger with speed, but at high speed and a "large" (7) distance setting, I want MORE distance. This is especially true if TACC becomes a part of the autopilot.

 

[Supercharged]

I wonder if this could be made retroactive to older Teslas.
A car this pricey should have had it when it came out two years ago.
Most cars have had it a few years now.