With ACC it can't acount for extra stopping distance when towing. I just increase following distance to max and override it in heavy traffic. More often than not its not issue as I'm typically going slower than rest of traffic.
The type of caravan braking system used in Europe and the UK uses some the caravans kinetic energy to compress the overrun braking mechanism. When operating correctly, this should only add perhaps 300 to 800 Newtons of force to compress the hitch, before the caravans brakes begin to apply braking effect, which will reduce the forward thrust on the compression. Thus the force onto the tow vehicle is modulated and should not cause the tow vehicles braking performance to be significantly altered.
This is roughly the equivalent of one additional adult passenger in the tow vehicle, and if the ACC cannot cope with that then something is seriously wrong with the cars braking system.
Because ACC is better at maintaining the distance between the vehicle ahead, it should make towing even safer, by removing the unreliable human trying to do the same.
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Even if as the Prof described there should be no significant change in the stopping distance towing or otherwise, there will be in changing conditions like wet roads differing surfaces, differing vehicle loading, aging tyres etc?
Then surely the ACC designer will have integrated some control system feedback from the radar to modify, modulate the braking effort?
Vehicle designers don't know what you will be towing, could be max unbraked trailer or light brake trailer. Hence recommendation not to use ACC while towing.
Designers do know - in UK/EU the max unbraked trailer weight is limited to 50% of the car's kerb weight, or 750 kg whichever is the lower.
I'm still intrigued as to exactly which authorities recommend not using ACC while towing - does the recommendation also apply to basic cruise, ie non-adaptive ?
Surely if on ACC and towing the system should sense the distance closing and it would ease the throttle or apply the cars brakes that bit firmer in order to maintain the distance. It may make the driving feel less smooth than when solo. But even solo with a fullly loaded car plus roofbox the system has to cater for the increased weight of the car.
There must be some in the Forum who have used ACC when towing. What is their experience?
I’ve not read about not using ACC when towing. Be interested in seeing a link.
There must be some in the Forum who have used ACC when towing. What is their experience?
I’ve not read about not using ACC when towing. Be interested in seeing a link.
I have used ACC when towing. It's fine. My car wont start Pilot assist when towing (steering assistance) which makes sense as it no longer knows the length of your outfit and the turning characteristics.
When I had ACC with lane change, if in the nearside land and coming up behind a slower vehicle, my vehicle would slow down, however when indicating to pull out the vehicle would immediately speed up and one could find themselves a bit closer to the slow vehicle than they would like to be unless you did a very quick land change which is not a good idea with a caravan in tow.
The problem you have described is not the fault of the ACC, which is only the system that controls the speed of the vehicle. Lane change is a separate system and part of an autonomous driving system.
At all times the driver is ultimately responsible for the control of the car and its interactions with other vehicles. If your particular vehicles Autonomous driving system or ACC does not manage a situation correctly and an incident occurs, then arguably the drive is not paying due care and attention or in full control of the vehicle.
If an system begins to miss handle a situation the driver should cancel or override the system to regain full manual control.
The obstruction is still partially in front of the vehicle which indicates that the ACC is very directional and therefore thinks that the obstruction is no longer there.
I am well aware that the lane change has nothing to do with the acceleration, but I was not very clear about my action when indicating. I hope you are not insinuating that I am not paying attention when driving because if I was not paying due care and attention I would have been involved in a mishap a long time ago.
Our current vehicle although it has CC, it does not have ACC or lane change and I feel more in control as I am able to judge a lot better instead of leaving it to the vehicle to decide what it wants to do.
The lane change is only a warning and as John mentions nothing to do with the vehicle speeding up.
On one of the rural A roads that we use to get home, there are bends and on either side of the bends are hedges. As you approached the bends even at 40mph, the car used to brake as it recognised the hedge as an obstacle and one had to over ride the ACC. It is quite safe to negotiate the bend at up to 60mph as the bends are not that sharp.
Sometimes the ACC would cause the vehicle to brake if a car entered the road on the right even though they were not in your lane and travelling in the opposite direction. A lot depended on the distance as the further away from the turning vehicle the better the chance of the ACC operating. It was a 2012 vehicle so software probably not as sophisticated as today's software.
With all the above taken into consideration, when driving along one needs to take into account that the vehicle may react differently to what is expected.
I'm glad my car doesn't have any of this autonomous stuff - I've managed well enough without it for nearly 60 years although I've always been a fan of basic cruise control.
I can’t envisage using ACC or Lane change other than on a motorway or long dual carriageway. In OZ and USA I’ve used it on long rural highways.But not surprised it does odd things on country lanes. 🤣
I also have used it in restricted speed section of roadworks. keeps the speed and comfortable spacing in control.
It is noticeable very frequently that the gap ahead seems to grow, so the radar bit has an easy life!!!
It is noticeable very frequently that the gap ahead seems to grow, so the radar bit has an easy life!!!
My present VAG car is the only one I've ever had with ACC. I find it very useful on most roads, even at 20mph. I can set the distance to the vehicle in front and it seems to keep pretty good distance control.
The biggest issue is if the vehicle in front turns of the road either to right or left, the system slows my car down, even though the vehicle ahead has moved well of my driving line.
The second issue which is not specific to the ACC is that when on dual carriageways or motorways, the distance I like to keep to the vehicle in front seems to invite fast boys to cut in which causes the system to brake to restore the distance.
The biggest issue is if the vehicle in front turns of the road either to right or left, the system slows my car down, even though the vehicle ahead has moved well of my driving line.
The second issue which is not specific to the ACC is that when on dual carriageways or motorways, the distance I like to keep to the vehicle in front seems to invite fast boys to cut in which causes the system to brake to restore the distance.
Any car maker share your recommendation, that when their vehicle is used for towing, the ACC system they use, is then not up to the job?
Obviously, each maker has it's own ACC or is it only one ACC maker modified for each car manufacturer. ?. Mercedes and Volvo at one time we're always the safety motivated leaders.
From Vitara manual's towing section
"For vehicles equipped with the dual sensor brake support system turn it OFF when towing. Do not use ACC, If not unexpected accidents related to the system being turned on may occur"
There is towing mode which will disable these systems.
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