Phantom braking

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DocScott

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I beg to differ. Drives that are going too slow get cited for it - because it's dangerous.
Defensive driving courses suggest (here's a second link; there are many more) if someone is tailgating you to slow down slightly, not speed up. This both encourages the jerk to pass you, and gives them more room in front of you to do so.

I understand that the norms for what is safe relative to the speed limit and the flow of traffic vary by region, and that in Southern California the expectation is that most people drive well over the limit, and that driving at the limit there can be a safety hazard. But that's still different from giving in to a tailgater.
 

undergrove

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Defensive driving courses suggest (here's a second link; there are many more) if someone is tailgating you to slow down slightly, not speed up. This both encourages the jerk to pass you, and gives them more room in front of you to do so.

I understand that the norms for what is safe relative to the speed limit and the flow of traffic vary by region, and that in Southern California the expectation is that most people drive well over the limit, and that driving at the limit there can be a safety hazard. But that's still different from giving in to a tailgater.

My first concern with a tailgater is to make sure I have extra distance between me and the car ahead so I won't have to brake suddenly. This often means slowing down somewhat. This may irk the tailgater, but it is the only safe thing to do. Then, if there is a lane to my right I will move over when it is safe to do so. These idiots wiil often try to push you faster regardless of speed if you aren't tailgating the car in front of you--even if you are in the rightmost lane. The only thing you can do there is keep an extra safe distance from the car ahead and watch out for them whipping around you and cutting in too fast out of spite.

California law requires a safe following distance. It used to be 1 car length for every 10 mph of speed. It is now a 3 second interval at whatever speed.
 

Dogwhistle

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Klaus-RF said: "Reminds me of an airplane autopilot system that could easily do automated take-offs but couldn't land. BTW - AP landing capabilities have been in commercial airplanes since at least 1977. ( Might not have been FAA Approved then, but the planes were fully capable of landing using AP alone including putting the gear down. )

Not exactly. 99% of all landings and 100% of takeoffs are still done by pilots. And it was only in the last 7-8 years that planes could even attempt to self land. Basically autopilot will get you lined up and very close to the ground, but the pilot has to have a visual of the runway or he/she will abort the landing...
Staying a bit off-topic here, but modern aircraft can conduct Category III autolands that do not require the pilot to have visual contact with the runway for the landing. The only restriction on autopilot usage (assuming all systems are functioning normally), is to disconnect the autopilot by 60 knots on landing rollout.
 

Klaus-rf

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going too slow is not the same as someone behind you coming up on you too fast.
Quickly slowing does indeed bring those behind you up on you fast. No?

The issue is the car on AP/NoAP slows too much, too quickly [when it doesn't need to] and the it doesn't resume back to normal speed - while traffic is passing on both sides and closing quickly from the rear - when the suspected reason for sudden braking has cleared. By several seconds. If it slowed then sped up again as soon as the obstacle cleared, the issue would not be so much a problem.

As many others have noted and I've stated here several times: AP/NoAp have absolutely no idea about closing traffic from behind. This is dangerous - especially when one adds phantom braking to the mix.

I don;t fault the semi driver at all. He had plenty of clearance until MY car (automagically) dropped 20MPH in 70MPH traffic and waited more than four seconds where it didn't speed up at all. That time period needs to be shortened to one second, for example.
 

DocScott

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Quickly slowing does indeed bring those behind you up on you fast. No?

The issue is the car on AP/NoAP slows too much, too quickly [when it doesn't need to] and the it doesn't resume back to normal speed - while traffic is passing on both sides and closing quickly from the rear - when the suspected reason for sudden braking has cleared. By several seconds. If it slowed then sped up again as soon as the obstacle cleared, the issue would not be so much a problem.

As many others have noted and I've stated here several times: AP/NoAp have absolutely no idea about closing traffic from behind. This is dangerous - especially when one adds phantom braking to the mix.

I don;t fault the semi driver at all. He had plenty of clearance until MY car (automagically) dropped 20MPH in 70MPH traffic and waited more than four seconds where it didn't speed up at all. That time period needs to be shortened to one second, for example.
We now have enough numbers to work it out.

Suppose the semi were following 3 seconds behind, which Undergrove states is the minimum required by California law.

Now your car drops from 70 to 50 mph for four seconds. So for four seconds, the semi, if it didn't change its speed would be closing at a relative speed of 20 mph. If it had been 3 seconds behind at 70 mph it would now be 3 - 4*20/70 = 1.9 seconds behind at 70 mph, meaning it would have closed only a bit more than a third of the following distance.

If your car then gradually speeds back up to 70 mph, the semi would never be at any risk of rear-ending your car, even if the driver of the semi didn't slow at all in response. Of course, that would leave the semi less than the three second following distance behind, and so the semi should slow slightly for a bit to let the distance open back up. It shouldn't be a crisis or nerve-wracking for anyone involved.

If your slowing by 20 mph for four seconds really did result in the semi being right on your tail, then the semi must have been tailgating before the braking occurred.

So while I agree that AP would be improved if it took more account of the rear camera view, I don't agree that the semi driver was blameless in the scenario you described.
 
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No. Its @MountainPass parent's fault for raising a kid that cares about other people.
I feel like I represent Tesla owners when I am driving, so behaving poorly makes all of us look bad. I have seen people saying we are the new BMW driver, so let's make sure to use our turn signals.