Blatto

Adaptive cruise control, dangerous

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I'm due to change my car in a few months time and have been very happy with the 2016 ST-Line 140 Fiesta I've had for the past 3 years.

I'm looking at the new St-Line X 140 version to replace it with so I arranged to take one for a test drive. I  wasn't expecting to get the opportunity until next month but the garage phoned me out of the blue and asked if I wanted to try one this afternoon so I took up the offer.

This one had the adaptive cruise control fitted so I thought I'd try that out.

It has three settings for the distance to follow the car in front and even on the furthest setting it was way too close at 70mph.

The 1st setting (the shortest distance) was downright dangerous about 2 to 3 cars lengths at 70mph. Why on earth would anyone follow that close at 70mph unless they have a death wish?

I let it stay on that setting for a few seconds before I took back control, a very unsafe system that needs rethinking.

I'm surprised they are even allowed to sell a car that automatically distances itself at less than 15 metres at 70mph, the absolute minimum should be about 70 metres and it wasn't even that on the furthest setting available.

The rest of the car was great and I'll definitely be getting one, but not with a suicidal/homicidal cruise control.

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There must have been a fault with that particular car; mine keeps much further than that away from the car in front at 70 at the lowest setting. In fact it’s the setting I use all of the time.

If the car you buy comes with adaptive cruise, there’s a setting in the menu that will switch it back to normal cruise.


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I’d go along with Andy on this. I have the adaptive cruise and the distance it keeps is perfectly fine, not close at all to being dangerous.

its probably become the one extra that I want a car to have no matter what, makes long journeys an absolute pleasure.

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Hmm strange it was a nearly new car only 3000 on the clock (not that new cars can't go wrong of course) and I mentioned it when I took it back. The guy said that was how they were in all the ones he's driven including the Focus.

How  much distance would you estimate yours are on the various settings?

Even on the furthest setting it was less then about 10 cars lengths maybe about 50 metres at most. That's way too close at 70mph.

Look at video from about 20 secs in, that's about how far back it was keeping me that's definitely dangerous

 

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11 hours ago, Blatto said:

Hmm strange it was a nearly new car only 3000 on the clock (not that new cars can't go wrong of course) and I mentioned it when I took it back. The guy said that was how they were in all the ones he's driven including the Focus.

How  much distance would you estimate yours are on the various settings?

Even on the furthest setting it was less then about 10 cars lengths maybe about 50 metres at most. That's way too close at 70mph.

Look at video from about 20 secs in, that's about how far back it was keeping me that's definitely dangerous

 

Don't forget the car doesn't need "thinking time" it will react instantly to the car in front slowing down.

.

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1 hour ago, Tiexen said:

 

Don't forget the car doesn't need "thinking time" it will react instantly to the car in front slowing down.

.

No, but you do if it fails to react.

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14 hours ago, DG97 said:

I’d go along with Andy on this. I have the adaptive cruise and the distance it keeps is perfectly fine, not close at all to being dangerous.

its probably become the one extra that I want a car to have no matter what, makes long journeys an absolute pleasure.

Same here.  I thought normal cuise control was fine until I tried the adaptive on the fiesta.  Wouldn't be without it now.  Never been worried about the distances either.  I have mine set to 3 and it brakes well in advance etc.  Like any dirver assistance feature it needs to be in conjunction with readiness to take manual control.

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1 hour ago, alexp999 said:

No, but you do if it fails to react.

In fairness, you’ll need more time if you need to react as your foot isn’t actually on the throttle but resting somewhere so not as quick of a transition to start braking if needed. 

Like all tech extras, they’re driving aids not replacements for a human. 

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2 hours ago, DG97 said:

In fairness, you’ll need more time if you need to react as your foot isn’t actually on the throttle but resting somewhere so not as quick of a transition to start braking if needed. 

Like all tech extras, they’re driving aids not replacements for a human. 

I think its safer than normal cruise, a numpty reading texts not paying attention will drive into the back of the car in front, adaptive would slow the car down.

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1 hour ago, Tiexen said:

I think its safer than normal cruise, a numpty reading texts not paying attention will drive into the back of the car in front, adaptive would slow the car down.

But equally adding more and more of these convenience features means stupid people that do that, will pay even less attention to the road than they already do(n't). 😞

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I agree with many of the opinions raised here :-

8 hours ago, pragmatix said:

If you dont like it turn it of in settings.

Yes, if I had a car with it fitted I could turn it off but I still think the implementation (assuming it wasn't a faulty car) that I experienced is still dangerous with it on. It's not just about the stopping distances it's also about being able to look far enough ahead to be able to assess any situations arising and take the necessary actions to avert an accident.

The one I test drove was following too close for me to be able to look far enough ahead to do that. That means other drivers using it will be driving unsafely in my opinion, so I'd rather it wasn't an option. I won't be paying £300 for that option after my test drive experience.

4 hours ago, Tiexen said:

I think its safer than normal cruise, a numpty reading texts not paying attention will drive into the back of the car in front, adaptive would slow the car down.

True, but I think it would just encourage muppets who drive whilst using a phone to be even more reckless than they already are.

A bit off topic but with regards to phone use I think it's about time to introduce a 12 month ban, phone destruction and possibly a jail sentence for being caught using a mobile whilst driving, the current pathetic fines are clearly no deterrent.

7 hours ago, DG97 said:

Like all tech extras, they’re driving aids not replacements for a human. 

Again true, but I still maintain the implementation I experienced is not aiding but just making people follow closer than is safe and making them think that 2-3 car lengths at 70mph is acceptable. It's not. 

For example  at 70mph you are traveling at about 31 metres per second. 2-3 cars lengths is about 12 metres, less than 0.5 seconds of reaction time . A good high performance car will take about 45 metres to stop from 70mph and that's in perfect conditions, with dry roads, good tyres suspension etc.. At 2 - 3 cars lengths you would wouldn't even hit the brakes before you were in the back of the car in front. From my test drive I'd say that the reaction time of the adaptive cruise was longer than 0.5 seconds.

The old adage of "Only a fool breaks the two second rule"  (and that was considered to be the minimum gap you should leave) is still a good rule to follow IMHO, using the above example a two second gap would be about 62 metres or about 15 cars lengths as a minimum. I try to leave about 100 metres at 70mph for a bit of an extra margin, not always to be driving at the minimum safe distance. Even at it's maximum setting the adaptive cruise was barely half that distance.

Does it also take wet/slippery roads into consideration? My guess here is  probably not, I bet it  keeps the same distance even in the wet.

I'll see if I can get another test drive in a different fiesta or focus just to make sure the one I experienced wasn't faulty, but I get the impression it was working ok, just badly implemented which  would be a shame if it is as I quite like the idea.

 

 

 

 

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42 minutes ago, Blatto said:

I agree with many of the opinions raised here :-

Yes, if I had a car with it fitted I could turn it off but I still think the implementation (assuming it wasn't a faulty car) that I experienced is still dangerous with it on. It's not just about the stopping distances it's also about being able to look far enough ahead to be able to assess any situations arising and take the necessary actions to avert an accident.

The one I test drove was following too close for me to be able to look far enough ahead to do that. That means other drivers using it will be driving unsafely in my opinion, so I'd rather it wasn't an option. I won't be paying £300 for that option after my test drive experience.

True, but I think it would just encourage muppets who drive whilst using a phone to be even more reckless than they already are.

A bit off topic but with regards to phone use I think it's about time to introduce a 12 month ban, phone destruction and possibly a jail sentence for being caught using a mobile whilst driving, the current pathetic fines are clearly no deterrent.

Again true, but I still maintain the implementation I experienced is not aiding but just making people follow closer than is safe and making them think that 2-3 car lengths at 70mph is acceptable. It's not. 

For example  at 70mph you are traveling at about 31 metres per second. 2-3 cars lengths is about 12 metres, less than 0.5 seconds of reaction time . A good high performance car will take about 45 metres to stop from 70mph and that's in perfect conditions, with dry roads, good tyres suspension etc.. At 2 - 3 cars lengths you would wouldn't even hit the brakes before you were in the back of the car in front. From my test drive I'd say that the reaction time of the adaptive cruise was longer than 0.5 seconds.

The old adage of "Only a fool breaks the two second rule"  (and that was considered to be the minimum gap you should leave) is still a good rule to follow IMHO, using the above example a two second gap would be about 62 metres or about 15 cars lengths as a minimum. I try to leave about 100 metres at 70mph for a bit of an extra margin, not always to be driving at the minimum safe distance. Even at it's maximum setting the adaptive cruise was barely half that distance.

Does it also take wet/slippery roads into consideration? My guess here is  probably not, I bet it  keeps the same distance even in the wet.

I'll see if I can get another test drive in a different fiesta or focus just to make sure the one I experienced wasn't faulty, but I get the impression it was working ok, just badly implemented which  would be a shame if it is as I quite like the idea.

 

 

 

 

I drive with the distance set to either the lowest setting or the second lowest and find the gap adequate. At maximum distance, the gap that is left is really large and more than safe imo.

You’d have to double check the manual but I think at maximum distance, the gap left is equivalent to give or take 2.2 seconds

The adaptive cruise doesn’t take into consideration rain etc as it’s a driving aid. It’d really be up to the driver to configure what distance setting is safe for the conditions or if driving with cruise control on in extremely poor conditions is a good idea. On that topic, I think the Belgians might have a law that states using cruise control on congested motorways is prohibited so all comes down to the driver to decide what is safe or not. 

Agreed it may make drivers more prone to distraction etc but saying that, no matter the car or cruise control you see people on their phones every day so truth is the punishments should be more severe than discouraging driver comforts like the adaptive cruise which my opinion is still that it’s one of the best options to have on a car.

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As to using it in the rain, no form of cruise control is safe for use in the wet.

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9 hours ago, alexp999 said:

But equally adding more and more of these convenience features means stupid people that do that, will pay even less attention to the road than they already do(n't).

Very true!

Software is not fault free. Boeing's software on the 737 has become infamous for driving aircraft into the ground! And the software on an aircraft has had very, very much more rigorous testing and quality checks than the stuff they bung into cars.

Trust Ford's software with your family's lives if you like, but I won't be doing that if I can help it.

 

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Had a look in the manual, at speed of 62mph the distance of the gap left by the ACC is as follows:

1 distance bar: Distance gap 28m

2 distance bars: Distance gap 39m

3 distance bars: Distance gap 50m

4 distance bars: Distance gap 61m 

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In

18 minutes ago, DG97 said:

Had a look in the manual, at speed of 62mph the distance of the gap left by the ACC is as follows:

Interesting. So even on setting on setting 4 it is only just over the 2 seconds gap. I'm fairly sure the Fiesta I tried only had 3 settings and the figure you quoted above of 50m for that setting is way too close, which is what I experienced on te test drive

So if the quoted figures are correct the first 3 settings are dangerously close and the 4th setting just on the bare minimum distance.

Setting 1 =  1 second gap

Setting 2 = 1.4 second gap

Setting 3 = 1.8 second gap

Setting 4 = 2.2 second gap

Setting 1 and 2 are suicidally close. 3 & 4 are absolute bare minimums in perfect conditions, and  should be double that in the wet.

14 hours ago, pragmatix said:

As to using it in the rain, no form of cruise control is safe for use in the wet

Based on the above figures it's not safe in the dry either but yes I agree I wouldn't use cruise control in the wet.

But since they have rain sensors for the wipers you would hope that they could use that to at least double the distances if rain is detected. Assuming the radar can reach that far.

11 hours ago, Tdci-Peter said:

Trust Ford's software with your family's lives if you like, but I won't be doing that if I can help it

Probably wise but I'd consider using it in the dry  if setting 1 was about 70 metres and 4 was about 150 metres.

If the above figures are correct then those of you who feel settings 1 & 2 are safe must be using a different definition of safe to me.

Many years ago I witnessed an old 60's style mini drive into a large concrete block that had fallen from a bridge on the A1M. I was traveling behind in my MKIII Cortina doing about 60mph and I was about 150 Yards (roughly the same in metres for you youngsters)  behind another car that was following the mini. The mini virtually stopped dead and disintegrated in a puff of dust, I expect he just didn't see it, I certainly don't remember seeing any brake lights. The car behind him was probably (based on my following distance) about 50 yards behind the mini he braked but still hit what was left of the mini, I remember seeing his brake lights but his following distance was too short, he hit it pretty hard. Settings 1 or 2 and probably 3 on the Above list would not allow you to avoid that incident. From 150 yards back I managed to stop about 25 yards from them and that took some doing (No ABS etc. in those days)

It was such an horrendous accident it is still burnt vividly in my memory, I jumped out to help but the mini driver no longer existed, the guy in the car behind him was still alive but trapped.

I was panicking as you'd expect, not sure how best to help, fortunately about 10 seconds later another guy stopped who was a doctor from the local hospital he was better able to deal with it than me so I rushed off to the nearest emergency phone (no mobiles in those days). To cut a long story short. The guy in the mini was dead and from what I saw there was very little of him left, the guy following him was in hospital for 6 months and had both legs amputated. I kept in touch with this guy until he died about 3 years ago. His life was ruined from that day.

I realise this is an extreme example and it's rare for the car in front to stop almost immediately but it can happen. I was over 5 seconds behind that incident and only just about stopped in time (granted I probably had worn suspension and was locked up in panic braking with no ABS in those days) but it taught me a lesson.

Keep as big a gap as is feasible you never know what's going to happen.

A modern car with good tyres, ABS and modern brakes I would leave about 100 metres at 70mph none of the settings listed above would feel safe to me.

 

 

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1 hour ago, DG97 said:

Had a look in the manual, at speed of 62mph the distance of the gap left by the ACC is as follows:

1 distance bar: Distance gap 28m

2 distance bars: Distance gap 39m

3 distance bars: Distance gap 50m

4 distance bars: Distance gap 61m 

According to the Highway Code, the stopping distance (excluding thinking time) at 60 is 55 metres, so on the face of it 3 of the above settings don't comply. I know most modern cars will stop in a shorter braking distance, and yes, it would be very rare for the vehicle in front to stop dead (but as @Blatto mentions, it could happen) but the HC is the guideline we're supposed to use.

I suppose all this is leads us to the bigger question: would you trust a fully autonomous car? Hours of interesting debate there!😀

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Sorry to throw this in the mix, but isn’t the point of adaptive cruise about maintaining distance from the car you’re following, not using it to stop the car dead.

Surely if cars in front of you were slowing to that degree, then you’d be braking too, thus turning off cruise control anyway.

 

 

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28 minutes ago, Jollyandy said:

Sorry to throw this in the mix, but isn’t the point of adaptive cruise about maintaining distance from the car you’re following, not using it to stop the car dead.

 

Yes, fair point - perhaps we're all getting a little carried away on this one. For stopping a car you need "collision assist" and "active braking" I believe, though the issue was whether the system leaves a big enough gap for the driver to carry out emergency braking and stop the car if necessary.

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Yes you are correct, hopefully you would intervene and brake yourself but my point is it's still making you follow at an unsafe distance so that when you do intervene you won't have the time to stop anyway.

I saw a test on the Fiesta St-Line (I think it was in an Autocar magazine) they do braking tests from various speeds. If my memory serves me correctly the Fiesta did 60-0 in just over 30 metres that's over a 1 second gap at 60mph add in the average reaction time of about 1 second to actually realising that you need to emergency brake and you'll hit the car in front if you are  following using settings 1 & 2. And thats in perfect conditions with the driver fully on the ball.

There are a number of other advantages to leaving a big gap apart from stopping in time.

1. you are able to see much further ahead to anticipate and plan

2. you aren't constantly on and off the brakes/accelerator, therby saving fuel and wear and tear.

3. If there's some muppet sitting on your tail way too close (either from ignorance/stupidity or using settings 1 and 2 of his ford Adaptive cruise control) if you leave a big gap to the car in front of you, you will be able to brake slowly and progressively and avoid having the muppet behind rear end you.

I'm sure there are a few other advantages too and no disadvantages as far as I can see.

 

 

 

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17 minutes ago, Blatto said:

I'm sure there are a few other advantages too and no disadvantages as far as I can see.

One disadvantage you do find is the muppets behind overtaking and filling up that nice gap you've so carefully left!😀

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2 hours ago, Eric Bloodaxe said:

One disadvantage you do find is the muppets behind overtaking and filling up that nice gap you've so carefully left!

Yes I get that all the time, but I'd rather have them in front of me where I can control the gap rather than right up me chuff.

I usually just lift off a fraction so I'm about 2mph slower than them and return the gap to a safe distance.

One disadvantage I have just thought of is if everyone kept about 100 metres apart at 70mph we probably wouldn't fit all the cars on the road these days.

But I'll leave the following dangerously close to the clueless muppets,  there seem to be enough of them on the roads to avoid that issue.

 

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Out of interest, are the settings speed related or fixed?  What I mean is, is the lowest setting designed to be used at slow speeds and the top setting at high speeds?  Or is it variable distance, so any setting would be roughly twice as far at 60 as it is at 30?  

I use standard cruise control all the time, it's one of the main must-have features on a car for me, but I'm yet to own anything with adaptive cruise. :smile:   

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6 hours ago, Blatto said:

Probably wise but I'd consider using it in the dry  if setting 1 was about 70 metres and 4 was about 150 metres.

It is not a problem to use it provided the distance met normal, sensible human requirements, and provided the driver is fully alert and in overall control. Then he/she has time to over-ride the system if needed or wanted. I suspect the user manual says something to the effect that this system in no way relieves the driver of overall responsibility.

I can't see Ford, or any car maker, accepting any responsibility for incidents any time soon. Which pretty much does in the concept of driverless cars. Autonomous maybe, but with a driver to take any blame for incidents. Then there is a huge problem with boredom and lack of attention, which will be almost impossible to avoid if autonomous steering is used.

A convoy system of close following vehicles can be done, but it would need communication between multiple vehicles to give advance notice of unexpected events, and would need heavily safety qualified software and hardware, pretty much to aerospace standards. Not a cheap or easy thing to obtain. But it might well work for lorries and haulage companies.

I would not trust any offerings by the main car manufacturers, they have a history of paring everything down to minimum cost, with plenty of examples of design and safety problems resulting from this.

In about 45 years of driving, I have had a few minor incidents, quite a few near misses or scary moments, and been in couple of car write-off crashes (not me driving!). That Mini incident must have been horrendous, but these events do change our attitudes to driving, usually for the better, ie. reducing un-neccessary risk. When I see a load of idiots ahead nose to tail at 60 to 80 mph, I increase my usually quite conservative gap even more. When idiots pull in to my gap, I just have to try to avoid getting too wound up, and say: it may be your funeral, but I won't allow it to be mine too!

 

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