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Discussion Starter #1
Forward Collision Alert/Forward Automatic Braking Reminder.....

Yesterday I almost T-Boned a knucklehead who shot out of a farm stand parking lot at a 90deg angle to the road I was driving on.
She jumped out from the parking lot on the right side of the road, crossing from my right to left across the two lanes maybe only 40ft in front of the Bolt. I was going about 40mph at that point- I nailed the brakes and cursed her out, just barely missing her by a couple of feet.. I could see her face was all flushed red from the near-accident stress.

Afterwards, I was pissed that the Forward Collision Alert/Forward Automatic Braking system on my Premier not only didn't stop the Bolt... but it never even activated the flashing HUD LED's! I have had it activate several times in the four months I've owned the Bolt, so I know it does function, but not this time?
After reading the text in the owners manual, I now understand the carefully worded description of the FCA/FAB operation and the limitations of the system...

"If the vehicle has Forward Collision Alert (FCA), it also has FAB, which includes Intelligent Brake Assist (IBA).
When the system detects a vehicle ahead in your path that is traveling in the same direction that you may be about to
crash into, it can provide a boost to braking or automatically brake the vehicle."

Pay close attention to the middle part of the second sentence... "When the system detects a vehicle ahead in your path that is traveling in the same direction". So, it seems that a vehicle entering your path from the right or left side at or near a right angle (like from a parking lot off to the side of the main road which is std for almost all parking lot entrances and exits) will not activate the system and will not warn you or brake your Bolt if someone suddenly shoots out from the side lot/road, etc..

So, be warned... .the FCA/FAB system may prevent you from rear-ending the vehicle ahead of you, but it's not going to do anything for vehicles crossing your bow!
 

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I think that you are correct. If a car is passing your bow it will activate when they are straight ahead of your Bolt, but not to the left or right of the path of the Bolt. I had someone come across from a side street and the collision alert went off and maybe the braking was boosted. I hit the brakes, the alert went off etc, but couldn't say what was the sequence. I stopped about 5 feet from impact. I was very happy to miss him, because the repair of a Bolt is very iffy at this point, with a lack of spare parts, not to mention dealing with insurance companies, etc. As always, driver beware.
 

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Discussion Starter #3
^ My FCA didn't even activate when the car was directly in front of me.. I'm thinking because she darted out so quickly from the right side at point blank range the system didn't have time to get her distance/closing rate and react? She had actually started to cross the two lanes.. then she stopped because the "window" was so small... then second guessing her original decision she gunned it out of the parking lot literally right in front of me.
 

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In my Cherokee, the collision avoidance did not activate if I was already depressing the brake pedal. "You've got this!", so to speak.
 

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Discussion Starter #5
In my Cherokee, the collision avoidance did not activate if I was already depressing the brake pedal. "You've got this!", so to speak.
I considered that possibility too, but it didn't mention that "feature" in the manual.

Sure would be nice to know....
 

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Pay close attention to the middle part of the second sentence... "When the system detects a vehicle ahead in your path that is traveling in the same direction". So, it seems that a vehicle entering your path from the right or left side at or near a right angle (like from a parking lot off to the side of the main road which is std for almost all parking lot entrances and exits) will not activate the system and will not warn you or brake your Bolt if someone suddenly shoots out from the side lot/road, etc..
I believe that the system operates off the forward-facing camera mounted below the rear-view mirror. I expect that it would "recognize" a car ahead of you and then watch for changes in it's size and position in order to judge whether or not there's a collision threat. Expecting it to recognize a threat coming out of nowhere is probably beyond its capabilities. There's a separate system that works off the ultrasonic detectors in the bumpers, but that one's only for objects like pedestrians that are very close.

These systems are still in their infancy. Right now, my attitude is that it might be able to avoid an accident, but it's certainly not something you can rely one.
 

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:DMine has activated several times since I've had my Bolt. Neat system, glad it's available.
 

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Discussion Starter #8
^ Did it actually apply the brakes or just the audible and LED warnings?
 

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It will and I have had it apply the brakes. It does use the front facing camera that is behind the rear view mirror, for both vehicle and pedestrian safety systems.

This is a decent video of the same system in a Cadillac.

I do think there are some subtle changes to the system since that video was made though. I have noticed in stop and go traffic that it seems to not only just detect that the car is there but when their brake lights come on. I've had the alert go off even when the car in front off me wasn't slowing, it was just close and their brake lights were on, just riding them not actually slowing. Doesn't happen often, just noticed it a few times. So I believe that the system is not only using shape and size of the images to detect car or pedestrian, but also processing the brake lights being on or off.
 

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I have been testing the low speed collision alert,and braking. Good place in (highway,city) gridlock to test the sensors, collision features .Experiencing the same red light flashes,with sound alerts as others;mine can be intermittent. Missing the active braking where I have been brave enough to almost hit the vehicle in front. ONLY my foot is hovering above the brake pedal. Where I have to press the brake because I don't sense the Bolt braking. The feature description,and vehicle setting option does include the word braking,so we should expect it. Pedestrian alert,and braking doesn't seem to brake either. These "safety"feature for vehicles isn't new. Many have had the collision avoidance feature(s) for years. Infiniti(?) had commericals in the past couple of years showing a female/male driver reversing,and the SUV braked as a child appeared behind the rear bumper. Subaru's eyesight commercial also shows/advertises actively stops an equipped vehicle,pre collision.
 

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I have been testing the low speed collision alert,and braking. Good place in (highway,city) gridlock to test the sensors, collision features .Experiencing the same red light flashes,with sound alerts as others;mine can be intermittent. Missing the active braking where I have been brave enough to almost hit the vehicle in front. ONLY my foot is hovering above the brake pedal. Where I have to press the brake because I don't sense the Bolt braking.
In the videos I've seen where they test these systems the car doesn't apply the brakes until the very, very last moment. I don't think you'd be able to keep your foot off the brake pedal long enough to determine if the car would brake by itself without risking actually hitting something if it doesn't.
 

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I had someone who was cutting across my lane (from lane to the left of me, into the lane to the right of me) and the colission alert when off, but they were already partially in my lane. I think the collision alert relies on a camera that looks for a shape of a car in front of it. So it only goes off it it sees something that looks like the rear end of a car. Not the side of a car.
 

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As for testing if the brakes are actually applied, I've often wondered myself...


...but I'm unwilling to actually run the experiment.
 

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Distance you're speaking of? Less than 31CM/ 1 FT?My video is within this distance,way too close to find out if you're going to avoid an impact.
 

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using this older thread to share an experience I had yesterday.

Driving in 'L' on a straight two lane road with cruise control set at 43 mph at 6:30 AM (still dark). The Forward Collision Alert (FCA) goes off and disables my cruise control. The car didn't appear to brake accept for the regen from being in 'L'. I was like, holy crap what am I about to hit? Kept looking for something, but nothing was there. Finally decided that the two buses that had just passed going in the other direction in the adjacent lane must have set it off.

I've heard others on this forum mention it going off going around a curve in the road, but this was on straight road. I've never had this happen before.
 

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Similar but different, I was driving a family member's Tesla M3 using cruise control when an oncoming car suddenly turned left across our path. The Tesla braked only after the car was past our direct line of travel.

This is one instance the AI software and sensors lag behind an experienced and focused human driver. I, seeing the car's speed was getting him out of our path, wouldn't have braked at all. A more cautious driver would have braked as soon as he/she saw the car commencing the turn. The Tesla only braked after the fact and to no purpose.

jack vines
 

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Driving in 'L' on a straight two lane road with cruise control set at 43 mph at 6:30 AM (still dark). The Forward Collision Alert (FCA) goes off and disables my cruise control.... I've heard others on this forum mention it going off going around a curve in the road, but this was on straight road. I've never had this happen before.
I've had it go off a couple of times over the past 2 years on straight, open roads with no obvious cause. It beeps and flashes briefly and then stops and doesn't apply the brakes. I chalk it up to a false positive by the software.

I don't know the details of how these things work, but I assume that it's a neural network that's been trained, and these are notorious for odd edge cases that trigger falsely. So I assume that the system generates a false positive, triggers the alarm, then is almost immediately presented with a new image a few feet further along the road which doesn't trigger, and thence cancels the alarms.
 

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I hate that **** red light and beeps :mad:
Goes off when I take a turn where traffic is still in the opposite lane.

I have also had it Not go off when it should have.
I am also thinking it doesn't go off if you are only going Under 10mph
 

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Today, I did notice that it beeps when there is a bus stopped on the next lane. Possibly reason why GM did not offer ACC on the Bolt.
 
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