I thought this an interesting video when Elon retweeted it. Basically the car is responding faster than the people do and keeping things from escalating. That said, having been on 101 when the cars in front start dancing like that I have to say my biggest worry isn't stopping in time its having someone behind me not stop.
The car responding faster allows for a less steep braking, which makes a rear-end less likely as the car behind you has more time to react (even assuming it doesn't have auto-pilot).
This is why I always try to brake early and long. Nothing annoys me more than drivers leaving it to the very last second, giving the person behind them as little time to react as possible.
I expect an autopilot could deal with that situation much better than a human as well. It should be able to predict if the car behind won't stop. Certainly better than a human driver could (if the human would even notice the car coming from behind with that happening in front). Then, assuming there is some space open in front, as there was in this case, it could accelerate to avoid the collision from behind. Now I'm curious whether Tesla's autopilot is already programmed to do this.
These were not on Autopilot, but human-operated maneuvers.
Why would Autopilot have a warning for frontal collisions but not for rear collisions? And why would Autopilot be speed-limited and all that if it was able to use launch mode to avoid a rear collision?
I think the consequences of this would be too significant for Tesla to silently implement. Given an unavoidable rear crash, it could cause a multi-car accident and increase the collision's severity relative to braking.
I was discussing the case of an avoidable rear crash. Vehicle approaching from rear, either not beginning to slow by a minimum expected distance, or slowing, but with apparently insufficient space to come to a stop. Space in front, allowing for safe acceleration. Seems logical to move out of the way, and I don't see any reason why it would increase the chances of a multi-car accident.
Sometimes it would misjudge an avoidable crash, though. When
an accident includes a vehicle in front, the middle car is oftentimes liable for following too closely. It might seem logical, but that "safe acceleration" could cause a pileup, and push it into an intersection for example.
That's why I usually break fast initially and check the rearview; extend the braking distance to allow extra room for the person behind if they are too close.
> That's why I usually break fast initially and check the rearview;
Great habit, but after seeing over 10,000 charts for chiropractic cases (was working on IT software to categorized it) I learnt another trick that many doctors tell their patients (unfortunately after the fact):
Once in a emergency breaking situation, before you look into the mirror, secure your neck/back of your head as hard as you can into the headrest cushion. This trick will "unite" your head with the seat and in rear-end, it will push you and the car both at the same time, instead of - from what I seen in 80% of Chiro cases - your seat head cushion hitting your head in a moment when its pulled hard to the back due to G-forces related to being in a rear-end.
I have to say seeing some photos I quickly got into a habit of first doing that, next checking mirror - if I assume someone might not make it and I still have room upfront, I go forward as fast and as close as I securely can.
When the car behind me is driving too close, I leave even more space than usual to the car in front to give myself time to brake slowly if anything happens.
I've actually found a really good solution to tailgaters: put very slight pressure on your brake pedal, enough to get the brake lights on, but not enough to actually cause any substantial deceleration. This will cause the tailgater to also slow down, but more than you because they have no way of telling how hard you are braking. The result is increased distance between you and them.
Do that a few times and even the most persistent tailgater gets it and either changes lanes or stops riding your ass.
When I'm driving, I'm usually always thinking about having escape paths. I get nervous if I don't have a shoulder or a clear lane next to me, unless traffic slowed to a near stop.
On freeways, each lane tends to develop its own speed, and at 4+ lanes the cognitive load starts to overwhelm me, especially when the relative speed difference between neighboring lanes is very high. At this point anyone in a slow lane may decide to try to pull out into the fast lane, or someone from the faster lanes might try to squeeze in to the queue of waiting cars; meanwhile if you try to unilaterally lessen the speed difference, the people behind and around you will get antsy and aggressive, often defeating the point.
These situations are some of the most dangerous that most driver experience: high speeds, large discrepancy between speeds, and limited escape paths.
I don't own a car but have a license and occasionally drive one. I'm not used to driving on highways with more than two lanes and when I spent a few months in the US I had panic attacks the first few weeks when riding at speed limit and there was no escape path. I had to leave the highway twice to recollect.
That's a good habit - however we don't know in this video if the SUV that got flipped over was braking suddenly, which can also cause collision without the rear car's anticipation (e.g. the rear car driver might be checking the right lane right before passing on the right etc. and missed that information for a split of a second right before collision.)
Please don't do this in the snow or in wet conditions. Sharp actions are what will make other cars change direction or magnify the effects of drivers that you have caused to panic. Putting on your hazards and slowing at a deliberate pace is safer for everyone behind you.
Also sudden hard brakes can cause injuries as well when the seat belt it tighten suddenly, but the software based braking will brake more accurately than a human, as you said in a timely manner.
I have no idea if it looks behind, or uses that information for anything. Ideally, it would time it such that when it was rearended, it was touching the car in front. It would significantly increase the mass and decrese the risk of whiplash.
Most Tesla's on the road don't have rear facing radar. I don't think the rear facing camera is used for anything other than parking. So, that leaves ultrasound, which has limited range.
I would think in theory they could use the camera alone to detect an approaching vehicle, and take some remedial action.
When the car is motionless (e.g. immediately after it has come to a stop from the emergency breaking), does the computer engage the breaks just soft enough so the car stays put?
And would this reduce the impact from behind if it were to happen?
I'm curious if you really want the brakes on full when you get hit from behind. It seems the cars would start to crumple in place until firmly together and you overcome friction, getting launched. With the brakes off, you would immediately accelerate, but perhaps with a lesser initial burst.
That's the decision I had to make one day. I saw a car coming to hit me from the rear. I took my foot off the brake and gripped the steering wheel, leaned back and relaxed. It worked out well, but I've always wondered if the brakes make any difference one way or the other.
I think you misread me. I was suggesting the computer don't put the break on full when stationary, but only enough to keep the car still (as the road may not be flat etc).
Well I would hope it would choose getting rear ended, particularly because that is the fault of the driver behind you. If you choose to slam into someone instead of letting someone slam into you, you are now at fault.
You can't control cars other than yours. On the bright side, if the car behind you is also a Tesla with AutoPilot 8.0+ with latest radar sensors, then you should be just fine :)
