Under the influence of adaptive cruise control

shadonoz said:
Interesting article in Wired today https://www.wired.com/story/tesla-autopilot-why-crash-radar/

Seems like too many Tesla drivers just don't get it. Should be obvious: when driving, DRIVE.

Great marketing to call it "auto-pilot", but maybe not the best idea after all.

No doubt all of US know not to rely too heavily on i-Activsense, right?
Click to expand...

I completely disagree with this article - w.r.t. CX-5. I EXTENSIVELY use i-Activesense in my CX-5. In fact, used it even in heavy rain conditions but constantly alert and attentive. Its has NEVER failed me except in 1 area: when I switch lanes because the car ahead is slow - my car is slow. During that brief period which lane change is happening my car starts to speed up sensing there's nothing in-between. I have sent 2 emails to Mazda whereby I suggested if turn signal is on then adaptive = OFF.

Case pointed out in article: Number of times has the car in front of me disappeared either to a different lane or took a ramp. In front number of times I have parked vehicle condition due to traffic. Here's what happens: Speed: 20 mph / cruise speed: 45 mph. Car in front: disappears. My car immediately and for an instant starts to accelerate. Almost immediately realizes there's again a car in front. Starts to de-accelerate. If distance sufficient, drops to the set cutoff speed and after which system pings and I take control. If distance in-sufficient - generates ALARM and flashes "BRAKE" on dashboard.

2nd. case - where adaptive cruise control actually saved me. Was driving at 65 mph. There's a setting using which I always drive at 3 car lengths. The car in front - suddenly braked hard and then rammed into the car in front (tail-gate). I was hearing all the crash sounds while my car braked - hard, automatically by cruise control and within less than a second beeped after which had to take control. If auto cruise control had not been on - I believe I would still been able to stop but I believe I would have been more near to the car in front in the 1st. place. When the dust settled - it became apparent it was a 4 car pile-up all because the 1st. car: braked and stopped trying to avoid a deer.

Personally - I think CX-5 uses the cameras behind the wind-shield in conjunction to the radar based sensors behind the emblem. In short - having radar and optical decision tools perhaps works better than just radar.
 
But Tesla DOES use cameras... eight of them [with a 360 degree view], plus 12 ultrasonic sensors, as well as the radar!

I absolutely agree with you that MRCC is wonderful. I use it virtually all the time on the highway, and often in town. And it has never let me down. But I don't expect it to substitute for paying attention to my driving.

It's interesting that many vehicles are starting to employ these safety features, but we keep hearing about Teslas hitting things, despite there being relatively so few Teslas on the road.

Maybe that's a commentary on Tesla's systems, or Tesla drivers, or that it's more profitable to write about a hotshot, expensive Tesla screwing up, rather than a "lowly" Chevy, Mazda, Volvo, whatever.
 
I use MRCC far more often than the cruise control in any other car that I have had. It really works well, i love it, it makes driving so much more relaxing. But as many have said, its not perfect in every situation and is no replacement for the driver being actively engaged in the drive.

Mr Musk cetainly seems to have captured the imagination of the glitterati and of The Millenials and Gen now/me.

Completely unrelated story:
Yesterday I read an article about Australian slang, and discovered a new phrase that has been added to the list in 2017:

“Milkshake duck ...”

This term describes phenomena that are initially perceived as positive, only to soon after be revealed as deeply flawed. Oxford Dictionaries defined the term as "a person or character on social media that appears to be endearing at first, but is found to have an unappealing back story".

And, by the way, Happy Australia Day all!
cd4a148268f2c58bc3059058607e6e11.jpg


Ned Kelly Pizza for breakfast! Baked beans, bacon, cheese and eggs. Mmmmm!
 
Last edited:
bmninada said:
I completely disagree with this article - w.r.t. CX-5. I EXTENSIVELY use i-Activesense in my CX-5. In fact, used it even in heavy rain conditions but constantly alert and attentive. Its has NEVER failed me except in 1 area: when I switch lanes because the car ahead is slow - my car is slow. During that brief period which lane change is happening my car starts to speed up sensing there's nothing in-between. I have sent 2 emails to Mazda whereby I suggested if turn signal is on then adaptive = OFF.

Case pointed out in article: Number of times has the car in front of me disappeared either to a different lane or took a ramp. In front number of times I have parked vehicle condition due to traffic. Here's what happens: Speed: 20 mph / cruise speed: 45 mph. Car in front: disappears. My car immediately and for an instant starts to accelerate. Almost immediately realizes there's again a car in front. Starts to de-accelerate. If distance sufficient, drops to the set cutoff speed and after which system pings and I take control. If distance in-sufficient - generates ALARM and flashes "BRAKE" on dashboard.

2nd. case - where adaptive cruise control actually saved me. Was driving at 65 mph. There's a setting using which I always drive at 3 car lengths. The car in front - suddenly braked hard and then rammed into the car in front (tail-gate). I was hearing all the crash sounds while my car braked - hard, automatically by cruise control and within less than a second beeped after which had to take control. If auto cruise control had not been on - I believe I would still been able to stop but I believe I would have been more near to the car in front in the 1st. place. When the dust settled - it became apparent it was a 4 car pile-up all because the 1st. car: braked and stopped trying to avoid a deer.

Personally - I think CX-5 uses the cameras behind the wind-shield in conjunction to the radar based sensors behind the emblem. In short - having radar and optical decision tools perhaps works better than just radar.
Click to expand...




@bmninada,

On that setting you referenced to in your 2nd case, those adjustments are not car lengths. They are a relative visual indicator of the spacing settings. If you were driving just 3 car lengths at 65mph, you would be way too close.

Compare the distance between you and the car in front the next time you drive at freeway speed and also in a urban street setting of 20-30 mph and you will see the difference.
 
Puyapim said:
@bmninada,

On that setting you referenced to in your 2nd case, those adjustments are not car lengths. They are a relative visual indicator of the spacing settings. If you were driving just 3 car lengths at 65mph, you would be way too close.

Compare the distance between you and the car in front the next time you drive at freeway speed and also in a urban street setting of 20-30 mph and you will see the difference.
Click to expand...

I mis-quoted - yes its relative. I have seen a setting = 3 (for example) when speed = 20 could be just 1 car length whereas in the same setting but speed = 80 could be 5 car length away. Its a solid system where it tries to keep the 2 second / 3 second / etc. second rule under most conditions.
 
bmninada said:
I mis-quoted - yes its relative. I have seen a setting = 3 (for example) when speed = 20 could be just 1 car length whereas in the same setting but speed = 80 could be 5 car length away. Its a solid system where it tries to keep the 2 second / 3 second / etc. second rule under most conditions.
Click to expand...


Yep that is what it is. I have mine set on that same setting only because I prefer to be safer. Thomas on Autogefuhl recommended that one setting below the max is what he prefers.

I don’t use it that much anyway. Only on freeway traffic that is not congested which is unheard of around here.
 
bmninada said:
I mis-quoted - yes its relative. I have seen a setting = 3 (for example) when speed = 20 could be just 1 car length whereas in the same setting but speed = 80 could be 5 car length away. Its a solid system where it tries to keep the 2 second / 3 second / etc. second rule under most conditions.
Click to expand...

That's exactly how it works, approx 1 second following time per bar, 2 bars minimum.

Call me reckless, but I really wish there was a one bar setting! Of course, Mazda will never do that. Liability, you know.
 
shadonoz said:
That's exactly how it works, approx 1 second following time per bar, 2 bars minimum.

Call me reckless, but I really wish there was a one bar setting! Of course, Mazda will never do that. Liability, you know.
Click to expand...

Correct me if I am wrong but isn't this the one bar you are talking about (uhm):

28v3jeq.jpg
 
Xeler8ing said:
Correct me if I am wrong but isn't this the one bar you are talking about (uhm):
Click to expand...

You are correct! But I could swear that I can't ever get lower than 2 bars at my normal 74 mph. I'll have to check next time I'm on the highway.

But that diagram seems to be wrong. It indicates that at 50 mph: 4 bars = 2.2 sec, 3=1.8, 2=1.3, and 1 bar=1.1 sec. It seems to me that the "headway" is much greater than that, but I rarely set it at 50. So maybe it's not a linear time relationship after all. Maybe it's got a lower limit [longer time/distance per bar] at higher speeds.

Or maybe I'm just confused. Wouldn't be the first time.

Hey Anchorman, got any tech docs on this topic?

And thanks for making me go to my OM to verify. I didn't realize you could change the set speed +/- 5 mph with a long press.

I learn something new every day from hanging around this group!
 
shadonoz said:
You are correct! But I could swear that I can't ever get lower than 2 bars at my normal 74 mph. I'll have to check next time I'm on the highway.

But that diagram seems to be wrong. It indicates that at 50 mph: 4 bars = 2.2 sec, 3=1.8, 2=1.3, and 1 bar=1.1 sec. It seems to me that the "headway" is much greater than that, but I rarely set it at 50. So maybe it's not a linear time relationship after all. Maybe it's got a lower limit [longer time/distance per bar] at higher speeds.

Or maybe I'm just confused. Wouldn't be the first time.

Hey Anchorman, got any tech docs on this topic?

And thanks for making me go to my OM to verify. I didn't realize you could change the set speed +/- 5 mph with a long press.

I learn something new every day from hanging around this group!
Click to expand...
Just use 2 or 3 bars and you should be fine
 
I don't see any advantage to travelling close cruising when you don't have too, so use a big gap between the car in front.
If someone fills my gap I just lift off and get it back.

Its the most effective way to save braking and fuel, and allows more reaction time.
 
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