Adaptive cruise control, dangerous

[Blatto]

1 hour ago, Tdci-Peter said:

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!

It makes me shake my head in disbelief every day. I travel about 30 miles up the A1M to work every day and probably 80% of the people are sitting about 2 cars lengths apart at 60 - 80 mph. If the person at the front of the train of muppets does an emergency stop every single one of them will be in the rear end of the car in front and then get rammed by the next idiot behind.

Many years ago they started a campaign on TV promoting the idea of keeping two chevrons apart. I'm sure many of you will remember it and have seen the chevrons painted on some of the roads, they were spaced at the approximate distance of 2 seconds at 70mph. Most of the ones we had on the roads round our way have long since faded away but the idea of two chevrons still exists in lots of peoples minds. Sadly a bloke I work with thinks two chevrons are two white lane marker lines as he's never seen the original chevrons. So he's blindly going along about 2 cars lengths behind thinking he's doing the right thing. I'm beginning to think the 80% I see every day think two white lane maker lines are the safe distance.

Add to that Ford car systems (and probably many other manufacturers) that have settings that go as low as 28 metres at 60mph and you have whole generation of drivers who have no idea of what a safe distance is.

 

[Blatto]

If the ford system worked like the VW Passat  I would consider getting it.

If you watch from about 2:20 in he mentions it has 5 settings and he is using it on 3. It appear to be leaving about a 3 second gap which is reasonable.

 

[martinf64]

2 hours ago, Blatto said:

If the ford system worked like the VW Passat  I would consider getting it.

If you watch from about 2:20 in he mentions it has 5 settings and he is using it on 3. It appear to be leaving about a 3 second gap which is reasonable.

 

So you will be getting a VW Passat next then...or you could try not using cruise control altogether, probably the cheaper option 🙄

[LondonFiesta]

I’ve skip read this so hopefully won’t upset anyone. I have two different types of cruise control in my cars, one optical based and one radar based. The radar one works well and can do (I’m not happy using it) in bad weather. The optical one often just gives up. So you may be right behind someone using it and the sun hits the screen, poof and it switches itself off. That’s way more dangerous.

I don’t know what the ford one is based on but as said, driver aids. The ones in my cars are meant to take you to a stop but I’ve bottled it every single time letting it do it itself. Especially as so far self parking it’s scuffed three of its wheels.

[Tdci-Peter]

1 hour ago, martinf64 said:

or you could try not using cruise control altogether,

I would recommend using the older, fixed speed cruise control. This can make driving more comfortable, as you can move around without mucking up the accelerator position, and can possibly make driving safer. It avoids those speed variations which can disconcert following drivers, when you change track on the CD / MP3, or something.

A little speed change may not be a problem for you, but if cars are following you nose to tail, each one will have to adjust speed slightly more violently, until at some point in the chain, there will be an impact. Unless at least one driver is keeping a sensible distance.

The manual cruise control may actually require a greater degree of driver awareness and involvement than with normal accelerator pedal control. You need to keep your eyes on the vehicles ahead to make smooth speed changes. Note the plural in vehicles! This makes for safer driving.

Adaptive cruise control removes that need to concentrate, at least for 99% of the time until it fails. Steering is a very light load on the human brain on a dual carriageway, so inattention to driving is an obvious and inevitable result.

If Boeing can not get their safety critical software 100% right with multi-million dollar budgets, then what chance have Ford (or VW!) got. Plus, as said above, a bit of dirt or bright sun on a windscreen can make the system fail unexpectedly at any time.

 

 

 

[Blatto]

2 hours ago, martinf64 said:

So you will be getting a VW Passat next then...or you could try not using cruise control altogether, probably the cheaper option

Well I wouldn't buy a car for this feature alone.

I was just trying to point out that from that Video it seems VW have done a decent job in making the car follow at a reasonable distance. Three Seconds is still a bit closer than I would like but the guy did say it had 5 settings and he  was using number 3 so I'd expect 4 & 5 would be fairly useable. Compared to the Fiesta I tested with the highest setting which was still way too close for safety. I'll stick with standard cruise control until Ford can get it right.

 

[Blatto]

Just looking in the ford owners  manual and I can't believe whoever wrote this can get away with it.

Under the adaptive cruise control section it shows this table 

Adaptive cruise control, distance between vehicle settings

Set speed               Graphic display, bars indicated between vehicles     Time gap, seconds     Distance gap     Dynamic behavior 
mph ( km/h)                                                               
62 mph (100 km/h)        1                                                                                1                31 yd (28 m)                          Sport. 
62 mph (100 km/h)        2                                                                                1.4             43 yd (39 m)                          Normal. 
62 mph (100 km/h)        3                                                                                1.8             55 yd (50 m)                          Normal. 
62 mph (100 km/h)        4                                                                                2.2             67 yd (61 m)                          Comfort. 
 

Basically they are suggesting that driving way too close to the car in front is Normal for settings 2 and 3 and the potentially homicidal/suicidal setting 1 should be encouraged by calling it Sport.

The only setting there that is even remotely sensible is setting 4 and that's barely the minimum distance you should be in perfect conditions and they choose to call that comfort.

They need to change it to this :-

 

Set speed               Graphic display, bars indicated between vehicles     Time gap, seconds     Distance gap     Dynamic behavior 
mph ( km/h)                                                               
62 mph (100 km/h)        1                                                                                1                31 yd (28 m)                          Extremely Dangerous immediate driving ban. 
62 mph (100 km/h)        2                                                                                1.4             43 yd (39 m)                          Very Dangerous 
62 mph (100 km/h)        3                                                                                1.8             55 yd (50 m)                          Dangerous
62 mph (100 km/h)        4                                                                                2.2             67 yd (61 m)                          Bare minimum

Or preferably  make a system that can maintain safe gaps, setting 1 should be 2.2 seconds and setting 3 a wet road setting which should be at least 4 seconds, and maybe have setting 4 for Ice which should be 10 seconds or more.

I just can't see how they can  put so much effort in to adding collision protection/airbags ABS, traction control etc... to a car in the name of safety and then include a system that encourages dangerously close following distances.

I know I've covered this topic before but I have only just seen their ridiculous descriptions for unsafe distances so felt compelled to bring it up again.

[Bobr]

You should never use cruise control, adaptive or otherwise, on a wet or icy road.

[primus1960]

 

5 minutes ago, Bobr said:

You should never use cruise control, adaptive or otherwise, on a wet or icy road.

Yup, I was gonna say that too but you beat me to it bob

[Blatto]

Yes, fair point. 

I was really meaning to point out that their descriptions and the distances that their adapative cruise control uses are dangerous and encourage people to think that that is somehow a normal/safe gap to use even if not using cruise control. Setting 4 is the only reasonable safe distance for dry conditions and that's pretty much a bare minimum. I wouldn't feel very safe always driving at the bare minimum distance.

3 seconds for Dry, 4-6 seconds for wet and 10 + seconds for ice would be more reasonable gaps.

Calling a 1 second gap "Sport" is very irresponsible. And calling 1.4 - 1.8 normal is just encouraging people to drive at unsafe distances thinking they are doing the right thing.

 

 

 

[Guy Heaton]

Agreed - why is there in fact any difference?  Either a distance is safe or it isn't, doesn't matter what mode or gear you're in.

[Paulkp]

I tend to agree with Michael.  It seems to me that "tailgating" has got far more prevalent, and also more vehicles now cut almost directly in front of you, having overtaken you on a dual carriageway or motorway. Far less than 2secs in front, and if they are SUVs or bigger, totally obscuring your view of the road (Hazards ?) ahead.

It does strike me that safety aids lull drivers into a false sense of security, and they should include a 12" spike aimed at the driver's Sternum !!

Happy Xmas !

[Bobr]

I agree with Michael.   Ford might be putting themselves in a very dangerous position.   If someone was to take those ridiculous distances seriously and be involved in a collision as a result Ford might find themselves in court.

[alexp999]

I do agree I would prefer for there to be longder distance options, I only ever use mine in the 4 bar (2.2 seconds) setting.

It is probably a limitation of the radar's ability to "see" far enough ahead to allow you to set it further.

One thing I will say, is that the 2 second gap rule (in dry conditions), primarily is to factor in a humans reaction time. It takes on average 1.5 seconds for a human to react, the car can react in milliseconds. So in theory, if the system is operating correctly, if a car performs an emergency stop in front of you without warning, the car will react almost instantly (milliseconds) and still have 99% of the 1 second gap to try and stop, where a human could spend 1.5 seconds of the gap to react and only have 0.5 seconds worth of stopping distance - obviously plus the time it takes for the car in front to come to a stop too.

The problem with it, is that the people you are following, don't know you have computer controlled radar cruise (with "instant" reaction times) and so it will make them unhappy about how close you are (it certainly would me, no matter how new/expensive the car looked).

[Eric Bloodaxe]

Never had adaptive cruise, so didn't realise there were different modes - I assumed you just set it as with normal cruise, and the system would adjust as required while maintaining a safe distance. Calling a cruise control setting "sport" sounds nuts to me!😄

[TomsFocus]

Does the cruise react differently in the different modes?  So sport may accelerate and brake more harshly than normal maybe?  I can't see any other reason for calling it that!  

[jbell]

I have standard (not adaptive) cruise control on my 2013 fiesta. One time the 'increase speed' button got stuck down so every time I disengaged cruise control it would re-enable as soon as I took my foot of the brake and start speeding up. 

Haven't used cruise control since. 

[Tiexen]

1 hour ago, TomsFocus said:

Does the cruise react differently in the different modes?  So sport may accelerate and brake more harshly than normal maybe?  I can't see any other reason for calling it that!  

I find adaptive cruise excellent (setting 4) on a "not too busy" motorway where you can sit in lane one following a coach at 65mph and let the car keep up with the vehicle in front slowing and accelerating as the vehicle in front does,

The danger is if anyone cuts into the space between (normally I would back off the throttle until the gap opens back up) the adaptive cruise  will immediatly hit the brakes which can be really scary especially if you have a vehicle behind!

Regarding the safety of the gaps the car on auto will brake much quicker than a driver - it doesn't need "thinking" time but i agree all but setting 4 is too close at 60mph

 

[alexp999]

1 minute ago, Tiexen said:

I find adaptive cruise excellent (setting 4) on a "not too busy" motorway where you can sit in lane one following a coach at 65mph and let the car keep up with the vehicle in front slowing and accelerating as the vehicle in front does,

The danger is if anyone cuts into the space between (normally I would back off the throttle until the gap opens back up) the adaptive cruise  will immediatly hit the brakes which can be really scary especially if you have a vehicle behind!

Regarding the safety of the gaps the car on auto will brake much quicker than a driver - it doesn't need "thinking" time but i agree all but setting 4 is too close at 60mph

 

The coaches are slow in your part of the country 😛

[Blatto]

10 hours ago, Paulkp said:

It seems to me that "tailgating" has got far more prevalent, and also more vehicles now cut almost directly in front of you, having overtaken you on a dual carriageway or motorway. Far less than 2secs in front

Yes very annoying now .

I remember back in the late 1970's and also during the 80's they used to have regular public information slots during prime time TV promoting road safety and showing drivers how to use roundabouts, safe distances etc... We need that to come back. That was where the slogan "Only a Fool breaks the 2 second rule" came from i.e. suggesting that as the minimum following distance.

8 hours ago, alexp999 said:

One thing I will say, is that the 2 second gap rule (in dry conditions), primarily is to factor in a humans reaction time. It takes on average 1.5 seconds for a human to react

Precisely, you need a minimum gap to give yourself a fighting chance of stopping if something unexpected happens.

At 62mph (the speed quoted in Fords manual, as above)  you are travelling at just under 28 per metres  second so with the average reaction time of 1.5 seconds you have already travelled 42 metres before you start braking.

Using Fords adaptive cruise control distances for 1 & 2 as above, but braking yourself you would already have  hit the vehicle in front before you got to the brake pedal.

I realise the car in front does not usually stop instantly but that is not always the case as I recounted in an accident I witnessed many years ago in another post (can't find the link at the moment). Also a high performance car takes about 30 Metres to stop from 62mph so even if the adaptive cruise control reacted instantly and braked for you you would still hit the vehicle in front on setting 1.

10 hours ago, Bobr said:

If someone was to take those ridiculous distances seriously and be involved in a collision as a result Ford might find themselves in court.

I suspect they didn't consider the legal implications of quoting unsafe distances if something goes wrong. Although I expect they'd point out the fact that it also says in the manual these are driver aids and that the are to be used with caution and the onus is on the driver to drive safely. 

My main concern is that in quoting those unsafe figures and having setting that will make your car follow the vehicle in front at those distances it will just make people think it must be safe.

8 hours ago, alexp999 said:

and so it will make them unhappy about how close you are (it certainly would me, no matter how new/expensive the car looked).

 The only way you can reasonably deal with someone tailgating you is to leave even bigger gaps to the car in front of you. If something happens up ahead you will have the ability to brake very gradually at first, hopefully getting the attention of the idiot behind you before you have to apply full braking to avoid the incident. If someone is sitting right up my posterior I try and leave at least a 10 second gap to the car in front.

 

[Tdci-Peter]

On 12/19/2019 at 9:47 PM, Blatto said:

Just looking in the ford owners  manual and I can't believe whoever wrote this can get away with it.

Under the adaptive cruise control section it shows this table 

Adaptive cruise control, distance between vehicle settings

Set speed               Graphic display, bars indicated between vehicles     Time gap, seconds     Distance gap     Dynamic behavior 
mph ( km/h)                                                               
62 mph (100 km/h)        1                                                                                1                31 yd (28 m)                          Sport. 
62 mph (100 km/h)        2                                                                                1.4             43 yd (39 m)                          Normal. 
62 mph (100 km/h)        3                                                                                1.8             55 yd (50 m)                          Normal. 
62 mph (100 km/h)        4                                                                                2.2             67 yd (61 m)                          Comfort. 

I think a group should get together and start a class lawsuit against stupid manufacturer stuff like this.

First, when dealing with a possibly lethal situation, the worst case of a brick wall stop must be accounted for. The vehicle ahead may hit a stationary van or lorry because the driver is asleep, or his/her automatic control systems have failed. Or it may hit an oncoming vehicle that has had a sudden blow-out or major failure of vehicle, control systems or driver. It may be rare, but as Blatto says, it does happen. 100km/hr is 27m/s, and to stop in 1 second needs a 2.8G deceleration. That means the tires have to give a grip of 2.8 times the car's weight. I suspect this is only possible under ideal conditions. Is there some clever gizmo in the car monitoring road grip and tire condition? I don't think so. And that G figure assumes instant reaction.

Then, is there still, in small print in the manual, the usual proviso that these gadgets are driver aids, and that the driver retains full responsibility for all situations? If so, the car must always be used in a way that the driver can cope with. A gap of at least 2 seconds would be the minimum. I very much doubt if the software in all this fancy, clever stuff has been tested and approved to the international safety standards for safety critical systems, like aircraft software needs to be. Even then, look at Boeing (just as an example!)

Finally, what about following vehicles. Each has a reaction time, whether human or machine, and a braking capability. The situation is common on motorways where one car just flashes it brake lights briefly for no good reason, then about 15 cars later on a packed road, cars are having to do an emergency stop. Without reliable wireless communication between all the vehicles at the speed of light, a group of cars or lorries can not behave like a train and all slow down together. Unfortunately, those two words "reliable" and "wireless" are mutually incompatible, always have been, and always will be. So that rules that out!

Completely crazy!

 

[Guy Heaton]

I can get the point about computer reactions allowing closer driving but it's not nice to have one behind you.

have noticed too some high end modern cars get very close after overtaking.  I wonder if that is computer controlled as well.  It's also not that nice.

[Paulkp]

Lots of valid points posted on this topic - should it move to "General Ford Related Discussions" ?

[TomsFocus]

1 hour ago, Guy Heaton said:

have noticed too some high end modern cars get very close after overtaking.  I wonder if that is computer controlled as well.  It's also not that nice.

I've noticed this come up a few times in this thread.  I often pull back a bit soon after a dual carriageway overtake to avoid holding everyone up in the overtaking lane (I'm usually on cruise at an indicated 70mph)...  I always wait until I can see at least their headlights in the rear view mirror though, and as I'm maintaining that speed the gap is constantly widening so never thought of it as an issue.  Just wondered if the headlights in the mirror is far enough or if there's something else I should be doing to ensure a big enough gap as it's not possible to work out the 2 second rule backwards.

[ShamusUK]

I find that even with the 4 car setting, i'm always feeling anxious when using adaptive cruise.

At 70mph, i would like the gap to be almost double (especially when conditions are not perfect). It should also increase the gap when the wipers are on.

It's a bit of a paradox really. Adaptive cruise is supposed to make the journey more relaxing. In reality it can be quite the opposite, unless it's a very quiet motorway in the middle of the night when you are sharing the road with a handful of cars and lorries.