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Regardless of how I set the following distance it stops ridiculously close to the vehicle in front. Like so close that it would fail a drivers test
Is this adjustable somewhere that I'm missing or do I have to manually override every time traffic stops so people in front of me don't think I'm an aggressive idiot?
 

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That is not adjustable.
Also I believe the manual states it's not for stop and go traffic (even though it works). But I'd have to go double check.
 

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How close is close? How far away do you want to be? Is it different than you would want if you were at a stop light? Granted I don't use it that often in stop and go traffic but I have (and used it on my Outback, too). It just seemed to stop at the same distance I would normally stop at a red light. I haven't noticed it to be abnormally close. It truly isn't designed for stop and go traffic although it is so nice to have that option.
 

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Many things affect the stopping distance, but, there's something else I've noticed from using the front camera, or simply getting out to look (in simulated situations - not on the highway) - the car looks really close when it's not, due to that big hood and high seating position.
 

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Discussion Starter · #6 ·
How close is close? How far away do you want to be? Is it different than you would want if you were at a stop light? Granted I don't use it that often in stop and go traffic but I have (and used it on my Outback, too). It just seemed to stop at the same distance I would normally stop at a red light. I haven't noticed it to be abnormally close. It truly isn't designed for stop and go traffic although it is so nice to have that option.
The rule of thumb I was always taught was that you should be able to see the tires of the car in front of you when stopped.
When ACC stops I'm probably about half that distance.

Maybe it is an illusion as Robert suggests. I'm not able to get out in traffic and check the actual distance
 

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The rule of thumb I was always taught was that you should be able to see the tires of the car in front of you when stopped.
When ACC stops I'm probably about half that distance.

Maybe it is an illusion as Robert suggests. I'm not able to get out in traffic and check the actual distance
If you have a two car family, or a neighbor who likes you, pull as close to their parked car as you feel ACC stops you, and then get out and check.

If you're dangerously close, then, I'd go in and have a dealership check it out. If they can replicate it, they may end up needing to recalibrate Eyesight.

Also, my Ascent seems to nose down a bit when stopping in heavy stop and go traffic. That seems to lend to the illusion for me. I often hover my foot over the brake pedal because of that, even when I know better.

Final note: following distance has minimal impact on stopped distance. It creates a variable follow distance that's based on your setting combined with your speed and the speed of the vehicle it's following. It's not a static setting except for coming to a full stop behind a stopped vehicle (which always seems to be about the same distance regardless of setting).
 

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The rule of thumb I was always taught was that you should be able to see the tires of the car in front of you when stopped.
When ACC stops I'm probably about half that distance.
Not to perpetuate the stereotype, but that's an awful polite distance! If you can see the tires of the car in front of you then you are pretty far. I find that ACC stops at an acceptable distance. If any farther away, people would try to squeeze in front of you.

This graphic might help. Car and Driver does "in-depth" reviews where one of the things they do is called the "obscured roadway" test. This is the distance in front of the car that you cannot see while properly seated. They have not yet tested the Ascent in this manner. I found a Hyundai Santa Fe, which should be reasonably similar enough.
 

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My wife mentioned the "seeing their tires" rule of thumb around when we got married. I had never heard that. I always heard a car length, 15 ish feet.
 

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My wife mentioned the "seeing their tires" rule of thumb around when we got married. I had never heard that. I always heard a car length, 15 ish feet.
This must be why so many drivers are an entire car length behind the white line at stop lights. They probably stop when the line is about to become about of view. I frequently pull up exactly to the line in the next lane over. Sometimes when they see you as a point of reference, they will pull up to the line. Most of the time, they just stay back there.

This also might be why when cars start to build up behind a stop light, many people stop at long distances from the car in front of them. Then they begin creeping forward inch by inch. Then everybody else behind them has to close in the gaps and the line of cars moves along like an inchworm. It would be awesome if people just pulled up to where they're supposed to be, but people are funny that way.
 

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That is not adjustable.
Also I believe the manual states it's not for stop and go traffic (even though it works). But I'd have to go double check.
In what amounts to a whole lot of words, this is correct. Page 42 of the Eyesight Manual (or at least the pdf version that I have).

Adaptive Cruise Control is designed for use on expressways, freeways, toll roads, interstate highways and similar limited access roads. It is not intended
to be used in city traffic. In the following conditions, do not use Adaptive Cruise Control. Doing so may result in an accident.
- Ordinary roads (roads other than those mentioned above) Depending on the driving environment (complexity of roads and other
factors), the system may not be able to perform as the traffic conditions require, and that may result in an accident.
- Sharp corners or winding roads
- Frozen roads, snow-covered roads or other slippery road surfaces The tires may spin, causing loss of control of the vehicle.
- Traffic conditions when frequent acceleration and deceleration make it difficult to maintain the following distance
It may not be possible for the system to perform as the traffic conditions require.
 

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When I took delivery of my Ascent, I asked whether Eyesight ACC could be used in stop-and-go traffic. I was told no, which was a bit of a disappointment. We also have a Tesla Model S and I absolutely love the ability to use the ACC in local traffic. It's a godsend when delivering my kids to school in the morning.

Despite the fact that people have said that the Ascent DOES come to a stop, I'm not anxious to try it out. I've already been to the body shop once to have a minor scratch repainted (in my first 1000 miles, no less), I don't need another trip for something more significant.
 

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Tesla States the SAME limitations...

When I took delivery of my Ascent, I asked whether Eyesight ACC could be used in stop-and-go traffic. I was told no, which was a bit of a disappointment. We also have a Tesla Model S and I absolutely love the ability to use the ACC in local traffic. It's a godsend when delivering my kids to school in the morning.

Despite the fact that people have said that the Ascent DOES come to a stop, I'm not anxious to try it out. I've already been to the body shop once to have a minor scratch repainted (in my first 1000 miles, no less), I don't need another trip for something more significant.
The Tesla absolutely shouldn't be used in stop and go traffic either, even though their newest software updates have improved "Traffic Aware Cruise-Control" performance in general. Like other systems, it too can have issues with identifying a stopped vehicle in time to stop itself (and has, and has crashed into things small and large). At let's say a city speed of 30 mph, that's 45 feet per second and limited time to identify a vehicle it's closing with at such a rate of speed.

As a matter of fact, the Tesla Model S system comes with virtually identical warnings (page 75 of the most recent online Tesla Model S manual, dated August 10, 2018) contrary to the opinions of most of the general public (other than Tesla puts in a lot more references to "serious injury or death" than I noticed in the Subaru manuals):

https://www.tesla.com/sites/default/files/model_s_owners_manual_north_america_en_us.pdf

Traffic-Aware Cruise Control is primarily intended for driving on dry, straight roads, such as highways and freeways. It should not be used on city streets.

Warning: Traffic-Aware Cruise Control is designed for your driving comfort and convenience and is not a collision warning or avoidance system. It is your responsibility to stay alert, drive safely, and be in control of the vehicle at all times. Never depend on Traffic-Aware Cruise Control to adequately slow down Model S. Always watch the road in front of you and be prepared to take corrective action at all times. Failure to do so can result in serious injury or death.

Warning: Although Traffic-Aware Cruise Control is capable of detecting pedestrians and cyclists, never depend on Traffic-Aware Cruise Control to adequately slow Model S down for them. Always watch the road in front of you and be prepared to take corrective action at all times. Failure to do so can result in serious injury or death.

Warning: Do not use Traffic-Aware Cruise Control on city streets or on roads where traffic conditions are constantly changing.

Warning: Do not use Traffic-Aware Cruise Control on winding roads with sharp curves, on icy or slippery road surfaces, or when weather conditions (such as heavy rain, snow, fog, etc.) make it inappropriate to drive at a consistent speed. TrafficAware Cruise Control does not adapt driving speed based on road and driving conditions.
Even the minimum set speeds are near identical (18mph for the Tesla, 20mph for the Ascent).

That being said, I have extensively tested ACC in such scenarios, with similar results as Tesla owners - with one exception. Having read the manuals for both, I know I MUST be hyper vigilant and be ready to intervene. There have been a couple of times during extensive testing that I have not been sure if the Ascent would stop in time or recognize the object in front of me in time. Very very few. Just like with the Tesla. Except, if one reads the news about what happens when someone isn't hyper-vigilant, and not lucky, they'll note the Tesla drives into stationary things as well. Sad fact of how the stuff still works.

As a matter of fact, The Tesla manual goes into even more detail with even more warnings about how the system should perform and when it shouldn't be used - and it too virtually matches the Eyesight manual.

Warning: Due to limitations inherent in the onboard GPS, you may experience situations in which Traffic-Aware Cruise Control slows down the vehicle, especially near highway exits where a curve is detected and/or you are actively navigating to a destination and not following the route.

Warning: Traffic-Aware Cruise Control cannot detect all objects and may not brake/decelerate for stationary vehicles or objects, especially in situations when you are driving over 50 mph (80 km/h) and in situations where a vehicle you are following moves out of your driving path and a stationary vehicle or object is in front of you. Always pay attention to the road ahead and stay prepared to take immediate corrective action. Depending on Traffic-Aware Cruise Control to avoid a collision can result in serious injury or death. In addition, Traffic-Aware Cruise Control may react to vehicles or objects that either do not exist or are not in the lane of travel, causing Model S to slow down unnecessarily or inappropriately.

Warning: Traffic-Aware Cruise Control may be unable to provide adequate speed control because of limited braking capability and hills. It can also misjudge the distance from a vehicle ahead. Driving downhill can increase driving speed, causing Model S to exceed your set speed (and potentially the road's speed limit). Never depend on Traffic-Aware Cruise Control to slow down the vehicle enough to prevent a collision. Always keep your eyes on the road when driving and be prepared to take corrective action as needed. Depending on Traffic-Aware Cruise Control to slow the vehicle down enough to prevent a collision can result in serious injury or death.

Warning: Traffic-Aware Cruise Control may occasionally cause Model S to brake when not required or when you are not expecting it. This can be caused by closely following a vehicle ahead, detecting vehicles or objects in adjacent lanes (especially on curves), etc. Adjust your following distance To adjust the following distance you want to maintain between your Model S and a vehicle traveling ahead of you, rotate the cruise control lever to choose a setting from 1 (the closest following distance) to 7 (the longest following distance). Each setting corresponds to a time-based distance that represents how long it takes for Model S, from its current location, to reach the location of the rear bumper of the vehicle ahead of you. As you rotate the cruise control lever, the instrument panel displays the current setting. Release the lever when the desired setting is displayed.

Note: Your setting is retained until you manually change it.

Warning: It is the driver's responsibility to determine and maintain a safe following distance at all times. Do not rely on Traffic-Aware Cruise Control to maintain an accurate or appropriate following distance.

Warning: Never depend on Traffic-Aware Cruise Control to adequately slow down Model S to avoid a collision. Always watch the road in front of you and stay prepared to take immediate corrective action.
One difference I did note is that the Subaru Ascent can use that engine and CVT, in conjunction with the brakes, to slow the Ascent to a full stop while going down a mountain. You'll note the Tesla manual says the Tesla may not be able to.

Anyway, I am not arguing either system is better or worse - they're different systems. I am pointing out that neither system, which are both the best in their respective classes, are designed for that, and BOTH come with copious amounts of warnings to NOT use their adaptive/aware cruise controls for anything but straight/straight-ish highways and never in stop and go traffic or on city streets and always while being in full control of the car and being fully vigilant of everything going on.
 

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I think, as with all of the various systems available, the major difficulty is stopping for a stationary vehicle when not previously following said vehicle. The instrument clusters on both the Tesla and the Ascent show the driver when a leading vehicle has been acquired. In those situations, I've never been concerned that the Tesla would not stop. When approaching stopped traffic at a light, for example, I NEVER take the chance that the car will slow / stop in time.

With respect to not using the Tesla ACC in stop-and-go traffic, not entirely true. From the Tesla manual:

"When following a vehicle, Traffic-Aware Cruise
Control remains active at low speeds, even if
Model S comes to a standstill. When the
vehicle is moving again, Traffic-Aware Cruise
Control resumes operating at your current set
speed."

You're absolutely correct that the manual states that ACC should only be used on highways / freeways. No quibble there.

Good to know that the Ascent will operate in a similar manner as the Tesla. Maybe I'll test the Ascent ACC in similar conditions. Hyper-vigilantly, of course.

Thanks for your response. Please don't take anything in my response to be a challenge to what you've said. I believe your intent is simply to provide information, and accept it as such.
 

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I think, as with all of the various systems available, the major difficulty is stopping for a stationary vehicle when not previously following said vehicle. The instrument clusters on both the Tesla and the Ascent show the driver when a leading vehicle has been acquired. In those situations, I've never been concerned that the Tesla would not stop. When approaching stopped traffic at a light, for example, I NEVER take the chance that the car will slow / stop in time.

Good to know that the Ascent will operate in a similar manner as the Tesla. Maybe I'll test the Ascent ACC in similar conditions. Hyper-vigilantly, of course.

Thanks for your response.
LOL!!!! You nailed it in sooooo many less words than my usual excessive verbosity. That's exactly it, and I too have never had an issue with the Ascent as long as that little green light is lit and the Eyesight ACC display shows the green "eye beams" and a car those beams are watching!

So yeah, same thing, similar warnings, and look for the little green LED. :grin: :tango_face_wink:
 

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All's good

Thanks for your response. Please don't take anything in my response to be a challenge to what you've said. I believe your intent is simply to provide information, and accept it as such.
Of course not!! Same here. :smile:

You'll note in the Eyesight manual similar stuff. "Don't do it!! Really, don't!!" and "here's what it will do..."

I always thought it odd that both of them (Tesla and Subaru) go into detail telling you not to do it, then go into detail telling you "when you DO perform that action, it will work like this". But like you/we said, it's all a matter of knowing both system's limitations and being aware of what's going on.

One of the instances I noticed (twice) was it not determining a stopped car was a stopped car. It didn't figure out what it was in time for ACC to do anything, so pre-collision system instead jumped in, because it is designed to see stopped objects. I was well aware of what might happen, so, I hit the brakes before pre-collision braking did anything except beep and warn "object detected".

The computer programmer and semi-pro photographer in me is wondering what it will take to make the systems detect static objects better. I used to wonder why that's where the identification problem is. Before researching this extensively, I thought the problem would lie in detecting MOVING objects. I was 180° wrong. Totally wrong, lol!

I realized after giving it some deep thought that when one is driving, a moving car in front of them is like a picture. A stopped car is a blur of something heading "towards" us.

In the human world, it's like looking at the car in front of you (picture) and being stopped on the side of the highway and watching a car whizz by (blur). Makes sense when I stopped to think about it. We've got the intellect and fuzzy matching capabilities to know "hey, it's a highway, that blur is a car" without waiting for it to be so close that we can touch it. I can't wait until cars can do that too. Soon, I hope.

Anyway, this reply is already a gazillion words... one last thing... Subaru has a timeline for their vehicles becoming fully autonomous... every now and then a Google search reveals it... most of the time, it's tough to find (and I have no clue why). But, if you're interested, Googling on the right day may turn it up.
 

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I've been a Tesla fan for quite a long time, so I've followed their development pretty closely. If you think about it, our cars already have the hardware they need for autonomous driving - a camera(s), control hardware for steering, acceleration and braking systems, and a computer. What is needed to complete the technology is the programming (and possibly more computing power, if needed to support the program).

Clearly, programming for all the things the human brain can react to is a daunting challenge. The driving is the easy part; our first gen Model S has that nailed - on an empty road in clear conditions. It's pretty well there in traffic also, but it's the things that go sideways that make true autonomous driving a thing of the future. We'll get there, but there's a lot that has to happen first.
 

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This must be why so many drivers are an entire car length behind the white line at stop lights. They probably stop when the line is about to become about of view. I frequently pull up exactly to the line in the next lane over. Sometimes when they see you as a point of reference, they will pull up to the line. Most of the time, they just stay back there.

This also might be why when cars start to build up behind a stop light, many people stop at long distances from the car in front of them. Then they begin creeping forward inch by inch. Then everybody else behind them has to close in the gaps and the line of cars moves along like an inchworm. It would be awesome if people just pulled up to where they're supposed to be, but people are funny that way.
People are funny. I try to stop centered on the sensor, or at the line if it's a camera system. I almost never creep up as where am I going to go unless it's a large gap like someone turned right and people are moving up for that.
 
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