Run away acceleration

Nor does my state, though some U.S. states may have that law.

Here, we can legally pass in any lane, but must have our own marked lane separate from the car being passed. The 'no passing on the (wrong side, pick your culture)' means only that we cannot go onto the shoulder, or use the passee's own lane, to pass.

Thus, we are not legally restricted to remain behind lane hogs or 'campers' going illegally slow in the so-called 'fast lane'.

 

DRCC is not going to accelerate that fast to close the gap. It has about the same rate of closing the gap as changing from 3 bar to 1 bar of following distance. Besides, the DRCC would have sensed the slower car as soon as the car in front of you left the lane therefore will lock into the slower car before any acceleration happens.

 

I'm talking about a large gap in front where the slower car in front of the car that's moved over is initially over the DRCCs 3 bar range and the car overtaking me is slowly overtaking.

 

Acceleration rate would also depend on drive setting, especially in DRCC. Eco slower than Normal and Power faster than both

 

The Prime has auto braking with the auto CC, it's a good safety feature. In a traffic delay on the freeway it will bring the car all the way to Zero mph.

 

The regular Prius has that too, it's a standard part of the full speed DRCC. Take note of my earlier post. If you are following a car with DRCC activated and that car comes to a stop, your car will come to a stop as well.

BUT if you are cruising but not "tracking" someone ahead of you and come up to a red light that already has cars stopped at it, your car will slam into the back of the stopped cars. DRCC does not track stopped objects unless it was an object it was already tracking that then stopped.

 

You won't slam into the stopped car, unless you going recklessly at high speed towards the red light, the auto braking will prevent that.

 

I promise you it will not do so. There are 2 forms of "auto braking" on the Prius. There is DRCC and there is PCS. DRCC is only meant to cruise the same speed as the car in front of you. With full speed DRCC it can even come to a complete stop safely and smoothly.

However, if you are not already tracking a car and you come up to a completely stopped car(say you were driving alone on the road at 50mph and you went around a curve and saw there was a red light ahead with a car already stopped) DRCC will completely 100% ignore it. The little "car on the road with the distance" prompt thing won't pop up like it normally does and you will hit the stopped car. DRCC does not and is not supposed to track stopped objects. It will stop your car, if it is already tracking it and the tracked vehicle stops.

PCS will kick in in that situation, but just watch videos online PCS does not completely stop the vehicle, it only slows it milliseconds before impact. It will flash "BRAKE" in red on the screen and beep loudly.

This information is in the manual I believe. It is a common, but extremely dangerous misconception. It does this to reduce false positives from road signs and the like.

 

This is a very dangerous misconception.

 

Right, PCS braking is good for approximately 40km/h delta-V, if I remember the videos correctly. If the speed difference between you and the obstacle ahead is greater than that, you're going to hit.

This is also the best-case outcome under controlled, dry conditions. YMMV.

 

PCS also brakes in the absolute most frightful, least graceful way possible. You certainly don't want to rely on it. It will SLAM the brakes at the very last second. It actually flashes the scary BRAKE message about 2 or so seconds before it actually brakes, to allow you some time to react manually. It also gives "driver assist" to the brakes, so it amplifies how hard you pressed the brakes because they've done research that shows most people don't hit them hard enough in panic stops. Very different from the smooth stop of DRCC.

 

If you're going round a curve towards a set of traffic lights (you can't see) at 50 mph, then the word "recklessly" applies.

 

It was just a clearly laid out hypothetical so that everyone would know exactly what I meant by "doesn't track stopped objects". Trust me, you don't want to rely upon PCS to stop your vehicle under any circumstances, no matter how slow or safely you are driving it is always a violent affair. If you came around that corner at 25mph the exact same thing would happen and you would slam into the car, or at the very best violently slam on the brakes and just miss it by a millimeter if you are already traveling very slowly.

 

But kithmo isn't saying it will! He says that it is more likely you'll crash if you drive too fast or recklessly and rely on the auto brake.

 

Basically, I agree not to rely on any tech to prevent crashing, I rely on my 45 years driving experience for that, but I do believe that at 25 mph the PCS would prevent you hitting a stopped vehicle in front just as efficiently as you could, it maybe more frightening as it doesn't slow down much before it slams on the brakes, but it does work, if it didn't then what's the point of putting it on the vehicle ?.
If you're going round a corner too fast and can't see the obstacle then you're just as likely to hit it, with or without PCS.

 

+1

 

I definitely agree with you, and the reason I mentioned what I did was so that other people would understand the limitations of the system and not allow themselves to get too careless.

From the marketing I've seen related to PCS it is intended to slow collision speed so that it is less likely to cause injury. It states it can stop the car, but the most it will slow it is around 19-25mph or so. I've seen various numbers but no definitive "this is the speed where PCS will stop the car, above that it will only slow it" just a few articles talking about it and vague generalities in the manual.

I know when I first bought the car, before I seriously investigated, I assumed that if DRCC was active and I came upon a completely stopped vehicle, or one who was traveling like 50mph or more slower than me that the vehicle would react to that car and stop as slowly and gracefully as possible, but it will not. I have seen people with my own eyes take their feet off the pedals while DRCC is active because they believe it will react to situations like that.

 

EURO-NCAP - I'm not sure if we all get the same version of AEB - but this detects a pedestrian walking across - most times!!! [START AT ABOUT 2:30]

But - that one didn't test with a parked or stopped car.

But this is a more generic, older Aussie demonstration, which does use a stationary object:

 

PCS braking is better described as "emergency braking", IMO, rather than "auto braking". That latter term is arguably dangerous as it downplays the seriousness a good degree; in comparison, "auto A/C" or "automatic transmissions" are comfort and convenience features.

We use abbreviations so much, but "collision" is right there in the name of "PCS". Casual readers need to understand its function is more like air bags than an everyday driving aid like DRCC. You don't want to need it, you certainly don't want to rely on it.

 

Thanks Alan. That indicates that at speeds below 25mph, PCS should be capable of stopping the car in an emergency providing the road surface is not contaminated.