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Has anyone here rear-ended a vehicle directly in front of them while in ACC? What were the peculiar conditions? I never read anyone posting about this, so it may be very very very rare event.

Although I have a few near misses, I never hit anyone, not even our trash cans. The collision detection has given me enough time to react and slam the brakes while in ACC.
 

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I suppose it's possible - Never heard of it happening though. With ACC, you also get high speed emergency braking which the other models don't have. I have experienced that one time and it applies the brakes quickly and HARD - Quicker than I could do and at least as hard, so it probably stopped me quicker than I could have done myself

Don
 

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Sure it's possible, there is more than one kind of accident not just rear enders. Was driving along and on coming car turned in front of me, noticed me, panicked and slammed on his brakes stopping right in my lane. Not having enough time to brake, I yanked the wheel to the left, throwing me into a four wheel side skid. The tires howled as I saw the passenger's eyes get wider knowing she was going to die. The tires heated up enough to grip and it jinked into the other opposing lane then I jinked around again to bring me back into my lane. Looking into the mirror I saw the passenger hitting the driver (her boyfriend/husband) over the head for almost killing her. If I hadn't been paying attention or tried to brake I would have smashed into them as there wasn't enough room or time to slow down. Thank Goodness I didn't have ACC.
 

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ACC isn't made to avoid accidents and drive in traffic. If someone jumps over in front of you, it will not detect them right away and you will rear end them if they panic stop or slow. Same for a sudden obstacle, or oncoming traffic or driving into a wall or median or divider. The system is dumb and makes people way too overconfident.

It only reliably works well to play follow the leader in open highway and light city traffic. Using it in bumper to bumper or 2 lane roads is asking for trouble.
 

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Am so glad that the Volt has a redundant system. Aside from the ACC's ability to do hard braking, the collission detection system is there to warn you also.
 

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Thank Goodness I didn't have ACC.
What does ACC have to do with it? Either you're paying attention or not. ACC wouldn't have prevented you from taking evasive action.

As for traffic, ACC actually works really well in bumper to bumper traffic, and relives the stress of constantly having to move your foot back and forth.
 

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ACC isn't made to avoid accidents and drive in traffic. If someone jumps over in front of you, it will not detect them right away and you will rear end them if they panic stop or slow. Same for a sudden obstacle, or oncoming traffic or driving into a wall or median or divider. The system is dumb and makes people way too overconfident.

It only reliably works well to play follow the leader in open highway and light city traffic. Using it in bumper to bumper or 2 lane roads is asking for trouble.
Evidently, yours works much different from mine - I don't find any of what you wrote to be true

Don
 

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So far, I’ve found if the person in front is already in my lane and close to the ‘distance’ I set, it keeps it.
If someone moves into my lane or pulls out in front- then it waits too long (for me) and will hit the brakes pretty hard (still keeping distance).
I always watch and just let it brake once (with my foot hovering over the brake) to see if it would work. It did, but I normally would just hit the brakes myself (or use the regen paddle) and slow down sooner. I like to keep a pretty good distance.

Keeping a wider distance dosn’t work very well in some places, where someone will dive into any space- not leaving enough room. But fortunately I rarely drive in such places.
 

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ACC isn't made to avoid accidents and drive in traffic. If someone jumps over in front of you, it will not detect them right away and you will rear end them if they panic stop or slow. Same for a sudden obstacle, or oncoming traffic or driving into a wall or median or divider. The system is dumb and makes people way too overconfident.

It only reliably works well to play follow the leader in open highway and light city traffic. Using it in bumper to bumper or 2 lane roads is asking for trouble.
LOL!

I trust ACC more than I trust my own reactions.

More than once it’s picked up a panic situation and slowed the car down without my intervention.

I’ll admit, the first time it happened it scared the crap out of me and I almost rear ended the car in front of me. See there is a design flaw... when the human steps on the brakes the entire system shuts off. So the car was hard braking under ACC and I put my foot on the brake pedal and turned it off. Dang near hit the car in front of me. Now I just let it do its thing as its way more effective.

Also, I drive bumper to bumper traffic with ACC on. 21k miles in one year three weeks. No accidents yet. ACC is best for heavy traffic where it reduces the fatigue and road rage by having the car reduce the workload off the driver.

I won’t ever own another car without ACC.

TJ


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I don't have ACC, but if you drive in LOW and have the cruise engaged, the forward collision alert (if activated) automatically disconnects the cruise resulting in rapid deceleration. It's not enough to bring it to a stop, but it's certainly good to have the car already rapidly decelerating while beginning to apply the brakes. All these safety features are very, very useful.
 

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As for traffic, ACC actually works really well in bumper to bumper traffic, and relives the stress of constantly having to move your foot back and forth.
Not really understanding this. I've driven my Volt in bumper to bumper traffic. Throw it in L and I barely ever have to touch the brakes.
 

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Find a few videos (YouTube has dozens of them) of ACC equipped Volts driven in traffic and you'll understand everything. You can drive across town without touching anything. After watching a few of those, ACC was a *must have* when I was Volt shopping

Don
 

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Find a few videos (YouTube has dozens of them) of ACC equipped Volts driven in traffic and you'll understand everything. You can drive across town without touching anything. After watching a few of those, ACC was a *must have* when I was Volt shopping
That's not a statement I was referring to.

Having said that I see no benefit to not touching anything. In fact, like others have expressed, I see it as a hazard as people stop paying attention.
 

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What does ACC have to do with it? Either you're paying attention or not. ACC wouldn't have prevented you from taking evasive action.

As for traffic, ACC actually works really well in bumper to bumper traffic, and relives the stress of constantly having to move your foot back and forth.
ACC is an accident waiting to happen because it takes you out of situational awareness (human nature) just like computers do on a plane. When an emergency happens the pilot doesn't have the situational awareness and people die. Works fine when there's no emergency though, just the regular run of the mill stuff it's designed for.
 

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ACC is an accident waiting to happen because it takes you out of situational awareness (human nature) just like computers do on a plane. When an emergency happens the pilot doesn't have the situational awareness and people die. Works fine when there's no emergency though, just the regular run of the mill stuff it's designed for.
like when you have everyone's number stored in contacts but you don't actually remember anyone's number?
 

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ACC isn't made to avoid accidents and drive in traffic. If someone jumps over in front of you, it will not detect them right away and you will rear end them if they panic stop or slow. Same for a sudden obstacle, or oncoming traffic or driving into a wall or median or divider. The system is dumb and makes people way too overconfident.

It only reliably works well to play follow the leader in open highway and light city traffic. Using it in bumper to bumper or 2 lane roads is asking for trouble.
Actually, I think FCA, Forward Collision Alert should detect if someone jumps in front of you, or at least my Volt has warned me a couple times when it's happened. Of course, you have to take evasive action.
 

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ACC is an accident waiting to happen because it takes you out of situational awareness (human nature) just like computers do on a plane. When an emergency happens the pilot doesn't have the situational awareness and people die. Works fine when there's no emergency though, just the regular run of the mill stuff it's designed for.
I’ll take ACC and ABS stopping me in an emergency well before I’d rather learn how to pump the breaks. Or to trust the guy behind me to know how to pump the breaks.

Your pilot analogy is also a poor analogy. Those computers only do what the pilot tells them to do. Fly at this altitude. Maintain this heading. Follow this route. Etc. ACC analyzes the situation in front of you and makes a decision based upon what it “sees.” The two are no where near related, although I do agree that the dumbness of the autopilot does lead to pilot complacency.

Will ACC lead to driver complacency? Doubtful. Your hands have to be on the wheel and that still leads you to be pretty engaged.

TJ


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Your pilot analogy is also a poor analogy. Those computers only do what the pilot tells them to do. Fly at this altitude. Maintain this heading. Follow this route. Etc. ACC analyzes the situation in front of you and makes a decision based upon what it “sees.” The two are no where near related, although I do agree that the dumbness of the autopilot does lead to pilot complacency.

Will ACC lead to driver complacency? Doubtful. Your hands have to be on the wheel and that still leads you to be pretty engaged.
A modern plane can almost take off and land by itself (in/from a modern airport). They could have pilotless planes but nobody would fly in them. Pilots do the take off and landing and little else. NTSB crash investigators say the computer/pilot interface is the weak point with them not maintaining situational awareness, they become too dependant on the computers. If professional pilots are not doing it with a load of passengers aboard, you know Joe Blow going down the road isn't either.
 

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A modern plane can almost take off and land by itself (in/from a modern airport). They could have pilotless planes but nobody would fly in them. Pilots do the take off and landing and little else. NTSB crash investigators say the computer/pilot interface is the weak point with them not maintaining situational awareness, they become too dependant on the computers. If professional pilots are not doing it with a load of passengers aboard, you know Joe Blow going down the road isn't either.
Take another good hard and long look at your facts. Your not totally wrong but your very off base.

TJ
(I’ve been flying planes since 1996)


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ACC isn't made to avoid accidents and drive in traffic. If someone jumps over in front of you, it will not detect them right away and you will rear end them if they panic stop or slow. Same for a sudden obstacle, or oncoming traffic or driving into a wall or median or divider. The system is dumb and makes people way too overconfident.

It only reliably works well to play follow the leader in open highway and light city traffic. Using it in bumper to bumper or 2 lane roads is asking for trouble.
I’m wondering if you have ACC? ACC is absolutely works well in stop and go traffic. I’ve had it for about a year now and it’s even more reliable going slower in the stop and go. If you are cruising along at 70MPH and you have clear road ahead and then come upon stopped traffic, that scenario is not as good in that you should really start slowing earlier than ACC would. I disengage ACC and take over when I see stopped traffic ahead outside the radar’s sight capabilities.

I think that ACC in the Volt is safer to use than AutoPilot in a Tesla not because it’s better (it’s not, Tesla’s is very good). ACC is safer in the Volt because it requires driver participation full time in the steering function. If you take steering out of the equation there’s a greater chance for a driver to become disengaged (cellphone, texting, email, whatever).

Again, ACC is perfectly suited for stop and go traffic.
 
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