[JRRF]

Just found this in the manual. A lot of ACC systems out there are not directly connected to forward collision alerts, but rather each has a unique setting. On the Volt they apparently are connected.

Changing the gap setting
automatically changes the alert
timing sensitivity (Far, Medium,
or Near) for the Forward Collision
Alert (FCA) feature. See Forward
Collision Alert (FCA) System 0 208.​

There's also been a bit of discussion here on how sensitive FCA is. It might be related to your Gap setting even if you are not using ACC.

 

[sparty]

Yes - this is 1 goofy thing about Volt's implementation. The other one with FCA/Automatic High Speed Braking is that we got the simple or poor man's implementation. The better system will use radar to detect open area when there is not sufficient time to stop and automatically steer into that open/safe area.

 

[JRRF]

Yes - this is 1 goofy thing about Volt's implementation. The other one with FCA/Automatic High Speed Braking is that we got the simple or poor man's implementation. The better system will use radar to detect open area when there is not sufficient time to stop and automatically steer into that open/safe area.

That is a significantly more sophisticated system. I'm not aware of anyone that does quite that much, and I can think of an array of other issues associated with steering the car out of your lane. To do anything close to that you would need to have 360 degree situational awareness.

Some of the more advanced systems today bounce a radar signal off the road to pickup a slowing/stopped vehicle ahead of the car immediately in front of you.

 

[BAZINGA]

Yes - this is 1 goofy thing about Volt's implementation. The other one with FCA/Automatic High Speed Braking is that we got the simple or poor man's implementation. The better system will use radar to detect open area when there is not sufficient time to stop and automatically steer into that open/safe area.

What manufacture offers this?

 

[limbery]

I occasionally get a false alarm with my HUD but have never had the car actually apply brakes. I love my ACC and have it set at the farthest following distance and I'm still always ready with my foot as I don't really trust it to never fail. It's scary that it doesn't have the far distance awareness and will approach a bunch of very slow or stopped cars ahead at the full speed that the cruise is set at and only quickly decelerates at a relatively late time so I usually override it in these circumstances. Works great in any kind of moving and flowing traffic though

 

[JRRF]

It's scary that it doesn't have the far distance awareness and will approach a bunch of very slow or stopped cars ahead at the full speed that the cruise is set at and only quickly decelerates at a relatively late time so I usually override it in these circumstances.

That's my biggest complaint as well. If you notice, when there are cars farther ahead of you, the display will not show any awareness of them until you get pretty close -- too close if you are cruising at 70. Some of the better systems out there will recognize vehicles ahead at a much greater distance, and start slowing much sooner, making manual intervention much less necessary.

The other issue with the Chevy ACC is that regardless of the gap setting, you wind up stopping 2 feet from the bumper in front of you. And my experience is that this distance is inconsistent. What should happen is that the distance you stop from the car in front of you should be proportional to the gap setting.

 

[hellsop]

The other issue with the Chevy ACC is that regardless of the gap setting, you wind up stopping 2 feet from the bumper in front of you. And my experience is that this distance is inconsistent. What should happen is that the distance you stop from the car in front of you should be proportional to the gap setting.

Why would it matter what stopped point matters? the descriptions I've been seeing is that gap distance is based on speed/time, not linear distance anyway. That is, the "close" following distance is bigger at 70 MPH than 50. Have you seen otherwise? What's the spacing for "00 MPH" then?

 

[JRRF]

Why would it matter what stopped point matters? the descriptions I've been seeing is that gap distance is based on speed/time, not linear distance anyway. That is, the "close" following distance is bigger at 70 MPH than 50. Have you seen otherwise? What's the spacing for "00 MPH" then?

That may be exactly what's wrong. The Chevy system may only be based on speed/time, with no other parameters. That may explain the different (and seemingly arbitrary) stopping distances, and why you sometimes wind up on top of the guy's bumper in front of you. I've used other systems where the final stopping distance is consistent, and is set based on the gap. It certainly makes good logical sense, but requires another parameter.

 

[Abbyhawk]

That is a significantly more sophisticated system. I'm not aware of anyone that does quite that much, and I can think of an array of other issues associated with steering the car out of your lane. To do anything close to that you would need to have 360 degree situational awareness.

Some of the more advanced systems today bounce a radar signal off the road to pickup a slowing/stopped vehicle ahead of the car immediately in front of you.

I have had 3 instances of FCA warning while following at very generous distances in foggy or rainy conditions. My system has looked beyond the vehicle immediately in front of me, and sensed the impending rear-ender between the next car and the 3rd one, much farther up the road! The driver of the car in front of me each time has not yet applied the brakes when my alert went off. I've had my foot on the brake pedal before that driver saw the problem in front of him!

 

[JRRF]

I have had 3 instances of FCA warning while following at very generous distances in foggy or rainy conditions. My system has looked beyond the vehicle immediately in front of me, and sensed the impending rear-ender between the next car and the 3rd one, much farther up the road! The driver of the car in front of me each time has not yet applied the brakes when my alert went off. I've had my foot on the brake pedal before that driver saw the problem in front of him!

Your car may have reacted to a slower moving car ahead of you before they braked for what was going on ahead of them, but the Chevy system does not look beyond the first reflective obstacle (i.e. the vehicle ahead of you).

 

[MaxSmart]

That's my biggest complaint as well. If you notice, when there are cars farther ahead of you, the display will not show any awareness of them until you get pretty close -- too close if you are cruising at 70. Some of the better systems out there will recognize vehicles ahead at a much greater distance, and start slowing much sooner, making manual intervention much less necessary.

I often get forward collision alarms while on ACC, which shouldn't happen IMO. It sees a 25mph car ahead while cruising at 70mph, rather than braking it beeps at me, so I slam on the brakes to slow down. Scratching my head as to why the ACC doesn't brake like it does if I were approaching a 55mph car.

 

[JRRF]

I often get forward collision alarms while on ACC, which shouldn't happen IMO. It sees a 25mph car ahead while cruising at 70mph, rather than braking it beeps at me, so I slam on the brakes to slow down. Scratching my head as to why the ACC doesn't brake like it does if I were approaching a 55mph car.

You are right -- it shouldn't happen. But I believe it's all based on distance, and then your closing speed winds up being too much for the 25 mph car. The Chevy system just requires more attention from the driver.

 

[scoops]

Your car may have reacted to a slower moving car ahead of you before they braked for what was going on ahead of them, but the Chevy system does not look beyond the first reflective obstacle (i.e. the vehicle ahead of you).

This is incorrect, the ACC system in the Volt will often track the car in front of the car you're following. If they start braking, the Volt will too (before the middle car has even reacted).

 

[JRRF]

This is incorrect, the ACC system in the Volt will often track the car in front of the car you're following. If they start braking, the Volt will too (before the middle car has even reacted).

I will continue to disagree unless you can provide a source for your assertion beyond your personal observations. I've owned various cars with ACC for 10 years and can assure you unequivocally that the Chevy does not track anything beyond the first bounce. And you are lucky to get that since its "sight" distance is very limited.

If this is your first car with ACC you may be so excited about it that you dream that it behaves like a third generation system that you've seen in other car commercials, but it doesn't. If you are traveling at speed and the car in front of you veers away from a just stopped vehicle ahead of it, don't take any bets on not hitting it.

 

[scoops]

I will continue to disagree unless you can provide a source for your assertion beyond your personal observations. I've owned various cars with ACC for 10 years and can assure you unequivocally that the Chevy does not track anything beyond the first bounce. And you are lucky to get that since its "sight" distance is very limited.

If this is your first car with ACC you may be so excited about it that you dream that it behaves like a third generation system that you've seen in other car commercials, but it doesn't. If you are traveling at speed and the car in front of you veers away from a just stopped vehicle ahead of it, don't take any bets on not hitting it.

Don't believe everything you think. This is not the first car I've driven with ACC; after all the technology has been around for at least a decade.

If you were in a condition where the car in front of you swerved: it would depend on if the Volt was already tracking the leader car. What did they do? Swerve too? Run into the back of the car they were following? Either way I would at least expect the FCA to sound an alarm and initiate emergency braking to reduce the severity of the accident. When a vehicle is already being tracked the distance the Volt can see is pretty impressive.

Here's a video showing exactly what I'm talking about in a Tesla V.1 (Similar hardware to the Volt):

My posit is that the Volt would have preformed very similarly.

Now, for your assertion that I am only going on personal observations (which, turns out, are correct) I present this excellent video by Mutley:
[video]https://vid.me/CSnw[/video]

 

[JRRF]

Don't believe everything you think. This is not the first car I've driven with ACC; after all the technology has been around for at least a decade.

If you were in a condition where the car in front of you swerved: it would depend on if the Volt was already tracking the leader car. What did they do? Swerve too? Run into the back of the car they were following? Either way I would at least expect the FCA to sound an alarm and initiate emergency braking to reduce the severity of the accident. When a vehicle is already being tracked the distance the Volt can see is pretty impressive.

Here's a video showing exactly what I'm talking about in a Tesla V.1 (Similar hardware to the Volt):

My posit is that the Volt would have preformed very similarly.

Now, for your assertion that I am only going on personal observations (which, turns out, are correct) I present this excellent video by Mutley:
[video]https://vid.me/CSnw[/video]

Go drive a few other cars with ACC and then tell me how impressive the Volt's forward vision is. I have not driven some of the new implementations by Toyota and other base Japanese manufacturers, but I can tell you unequivocally that the systems by MB, Volvo, Audi, Acura, and even Dodge are much better. BMW's is about on a par with the Chevy.

The Volt is NEVER tracking the car two in front of you. This ain't no Tesla.

When the car in front of you moves away, if the leader car is already stopped, then since you have NOT been tracking it, the Volt will treat it like a brick wall. You will get an alert, the system will attempt emergency braking, and if you are traveling more than 25 mph you will hit that car. If that leader car is moving very slowly it will take quite a bit of time for the Volt to "detect" it, and depending on your closing speed you may still hit it.

What you are asserting is not impossible, and there are cars (including Tesla) that have implemented this. But Chevy has not. Go try it out and let us know how it goes

Here's the Warning from the manual that your insurance agent will read back to you after the crash (emphasis added):
"For example, the
system may not brake for a
vehicle it has never detected
moving. This can occur in
stop-and-go traffic or when a
vehicle suddenly appears due to
a vehicle ahead changing lanes.
Your vehicle may not stop and
could cause a crash"

 

[scoops]

Go drive a few other cars with ACC and then tell me how impressive the Volt's forward vision is. I have not driven some of the new implementations by Toyota and other base Japanese manufacturers, but I can tell you unequivocally that the systems by MB, Volvo, Audi, Acura, and even Dodge are much better. BMW's is about on a par with the Chevy.

The Volt is NEVER tracking the car two in front of you. This ain't no Tesla.

When the car in front of you moves away, if the leader car is already stopped, then since you have NOT been tracking it, the Volt will treat it like a brick wall. You will get an alert, the system will attempt emergency braking, and if you are traveling more than 25 mph you will hit that car. If that leader car is moving very slowly it will take quite a bit of time for the Volt to "detect" it, and depending on your closing speed you may still hit it.

What you are asserting is not impossible, and there are cars (including Tesla) that have implemented this. But Chevy has not. Go try it out and let us know how it goes

Here's the Warning from the manual that your insurance agent will read back to you after the crash (emphasis added):
"For example, the
system may not brake for a
vehicle it has never detected
moving. This can occur in
stop-and-go traffic or when a
vehicle suddenly appears due to
a vehicle ahead changing lanes.
Your vehicle may not stop and
could cause a crash"

*sigh* I feel like I'm speaking right by you. You said the Volt NEVER looked past the car in front of it and I proved that statement wrong.

I never said the Volt had the best ACC in the entire world. I have *no* doubt that there are better ones out there. What's your point?

Did you watch the video of the Volt tracking two in front? I have seen it with my own two eyes and felt it with my own two butt cheeks. The Volt will aggressively brake if the car in front of the car you are following slows down (Often they're almost coming to an almost complete stop to take a right turn into a driveway). EVEN IF THE BRAKE LIGHTS OF THE CAR YOU ARE FOLLOWING HAVE YET TO COME ON. *Of course* This isn't always the case!

Dude, you're quoting the manual from a hyper-risk-adverse company. Of course it's gonna say that. Did you notice that it also said *MAY*?

I don't know what else can be said...? If I'm traveling at 93mph (the highest speed ACC will work at) and am at the closest distance setting following another car also going 93mph and all of a sudden the car in front of me swerves because there's some drunk guy on a riding lawnmower in the middle of the road then the ACC ain't gonna do Jack. But there are situations where the Volt will react before you even know that something is wrong because you can not see beyond the car in front of you but the Volt can.

 

[JRRF]

*sigh* I feel like I'm speaking right by you. You said the Volt NEVER looked past the car in front of it and I proved that statement wrong.

I never said the Volt had the best ACC in the entire world. I have *no* doubt that there are better ones out there. What's your point?

Did you watch the video of the Volt tracking two in front? I have seen it with my own two eyes and felt it with my own two butt cheeks. The Volt will aggressively brake if the car in front of the car you are following slows down (Often they're almost coming to an almost complete stop to take a right turn into a driveway). EVEN IF THE BRAKE LIGHTS OF THE CAR YOU ARE FOLLOWING HAVE YET TO COME ON. *Of course* This isn't always the case!

Dude, you're quoting the manual from a hyper-risk-adverse company. Of course it's gonna say that. Did you notice that it also said *MAY*?

I don't know what else can be said...? If I'm traveling at 93mph (the highest speed ACC will work at) and am at the closest distance setting following another car also going 93mph and all of a sudden the car in front of me swerves because there's some drunk guy on a riding lawnmower in the middle of the road then the ACC ain't gonna do Jack. But there are situations where the Volt will react before you even know that something is wrong because you can not see beyond the car in front of you but the Volt can.

scoops, by all means live your dream. I just hope you are never behind me.

 

[scoops]

scoops, by all means live your dream. I just hope you are never behind me.

You're either a troll or a twat. I'm not sure which and frankly I don't care.

I've proven you wrong as any reasonable person would see. Of course you can't come back with anything constructive to add to the conversation because your position is completely wrong. I've never been in a car accident and I do everything I can to minimize my chances of ever being in one. I use ACC as a tool to alert me of potential problems and augment my own senses. You'd be damn lucky to have me behind you.

You're wrong.

Wrong.

 

[scoops]

I often get forward collision alarms while on ACC, which shouldn't happen IMO. It sees a 25mph car ahead while cruising at 70mph, rather than braking it beeps at me, so I slam on the brakes to slow down. Scratching my head as to why the ACC doesn't brake like it does if I were approaching a 55mph car.

This confused me when I started. The Volt is simply trying to wake up the driver to take over. The ACC has deemed the situation to be likely dangerous and could end up outside of the ACC's wheelhouse. It's best for a human to take over. I'm sure the ACC could handle it in many/some cases but it's best for a human with better oversight on the situation to take over.