ABS and braking when cornering

[Kimosabe]

My 4x4 has all the bells and whistles including ABS, presets for various surfaces, ESP etc etc. As it is capable of being driven off road, it is more than capable of managing cornering on Tarmac at reasonable speeds.

I am a good driver and the evidence for this is my near 30 years of untarnished motoring, without any further training than my basic test. Before I enrolled with the IAM I had never driven into anything while turning a corner and had never skidded off a road due to excess speed but my biggest hang up comes when trying to fix something which was not broken. I'm putting a lot of effort into not braking when cornering than I think I need to.

The 'never brake when cornering mantra' seems defunct in a car with ABS because even when i floor the brake pedal, the brakes won't lock, the wheels will turn and the car can still be steered. On such a modern car being driven within speed limits on tarmac roads, is it still necessary to brake before a corner or bend and if so why?

[Mr Cholmondeley-Warner]

For safety. For control. For stability. For passenger comfort.

Safety - not carrying more speed into a corner than you can lose in the distance you can see to be clear.
Control - not doing more than one thing at once, or asking the tyres to do two things (braking and steering) at the same time.
For stability - braking while the car is not travelling in a straight line will lead to sideways forces on the car which will upset it. In a worst case scenario, it might spin or roll. ABS will be no help at all with this.
For passenger comfort - cars feel more balanced and "natural" cornering under power than they do under braking. Your passengers will thank you for removing the feeling that you go into corners too fast.

To pass the IAM test, and if you want to progress further with your driving, you will find most official organisations expect you to drive to the System. It takes some getting used to, but the more you press on, the more you will find the System is there like a safety net to help you keep out of trouble. It's a set of rules that apply all the time. You've already enrolled with the IAM, so despite your statement that "I am a good driver", you obviously know you could be a better one. Bear with it, and hopefully it will become more natural as you get more proficient at it. It is a big change from how many of us drove before we started on AD, but it's worth it.

Edit - add further info.

[michael769]

On such a modern car being driven within speed limits on tarmac roads, is it still necessary to brake before a corner or bend and if so why?

It's more comfortable for passengers?

[GJD]

My 4x4 has all the bells and whistles including ABS, presets for various surfaces, ESP etc etc. As it is capable of being driven off road, it is more than capable of managing cornering on Tarmac at reasonable speeds.

I am a good driver and the evidence for this is my near 30 years of untarnished motoring, without any further training than my basic test. Before I enrolled with the IAM I had never driven into anything while turning a corner and had never skidded off a road due to excess speed but my biggest hang up comes when trying to fix something which was not broken. I'm putting a lot of effort into not braking when cornering than I think I need to.

The 'never brake when cornering mantra' seems defunct in a car with ABS because even when i floor the brake pedal, the brakes won't lock, the wheels will turn and the car can still be steered. On such a modern car being driven within speed limits on tarmac roads, is it still necessary to brake before a corner or bend and if so why?

I'm not fond of emphasising it as 'never brake when cornering'. I've seen people do surprising, perhaps alarming things when they've been presented with a hitherto unseen hazard mid bend and they've forgotten they're allowed to brake when cornering. When you're assessing the distance you can see to be clear in a bend, with reference to the limit point and (as Ancient would rightly insist I mention) all the closer hazards, going through your mind is "Can I stop? Can I stop? Can I stop?" because if something changes, you might need to stop or slow down. So for starters:

YOU ARE ALLOWED TO BRAKE WHEN CORNERING.

Right, that's that out of the way .

To describe what the Syetem is about, I would emphasise it as getting the car set up for the bend before you arrive (just as for any other hazard). Do you find the way the System gets you to sort out position, speed and gear before you arrive to be strange or troubling for any other hazards, or is it just (some?) bends?

[zadocbrown]

I am a good driver and the evidence for this is my near 30 years of untarnished motoring, without any further training than my basic test......... my biggest hang up comes when trying to fix something which was not broken.

Forgive me, but if you are satisfied with your driving and don't want to change it, what are you hoping to achieve through further training?

This is an 'advanced' driving course - it's not aimed at people whose driving is 'broken', it's aimed at people who already drive to a reasonable standard who wish to acquire additional finesse/safety margin. That will nearly always mean changing something you could strictly speaking leave alone. It's not a matter of right and wrong, it's a matter of always seeking improvement.

In answer to your specific question - we need to say firmly that 'Never' braking on a bend is NOT the aim. Sometimes there are good reasons for doing it, and as you have established it rarely leads of itself to anything dramatically untoward. However, it is advantageous under normal conditions to be under power before entering the bend. The advantages are (not necessarily exhaustive and in no particular order):

a) The forces will help keep passengers in their seats, instead of throwing them forward and out, increasing their comfort
b) The car will be more balanced and responsive to driver inputs through the bend
c) Normally you want to accelerate after a bend, and if you are already on the gas this will happen more smoothly and quickly
d) If you normally finish braking before entering a bend, when you get it wrong you have more room to sort it out than if you normally brake all the way into a bend.

[Gareth]

I am a good driver and the evidence for this is my near 30 years of untarnished motoring, without any further training than my basic test......... my biggest hang up comes when trying to fix something which was not broken.

In answer to your specific question - we need to say firmly that 'Never' braking on a bend is NOT the aim.

I think we need to say something more here - something that relates to the severity of braking, how the braking is applied, the sharpness of the bend, the condition of the road surface, the condition of the rear tyres, and how slippery it is.

The reason to avoid braking in a bend is simply that it can lead to a major loss of control in some circumstances. The particular circumstances will depend on some or all of the factors listed, and possibly others not already mentioned, such as vehicle dynamics, condition, and so on.

A loss of control will be more likely if the road surface is uneven or slippery, if the rear tyres are near to the end of their useful life, if the braking is applied sharply as might happen in an emergency, or the impetus to lose control is greater than can be compensated for by whatever electronic trickery is fitted to the vehicle, (bearing in mind that a high proportion of vehicles on the road today either have no such systems or only have systems with limited capability).

The extent of loss of control is likely to be more than can be safely recovered within the road space available, if at all, by the vast majority of drivers.

[Slink_Pink]

It's worth noting that it's preferable to drive such that the safety systems do not intervene. This is part of the reasoning behind the system of car control. Also, as others have mentioned, no matter how good the safety system, you can't defy the laws of physics.

[Astraist]

The question of braking while cornering is an interesting one. But first, to address the OP's question: With ABS you can floor the brake pedal (if the need for sudden braking arises) mid-corner, or brake in a straight line and than evade, all while braking. But this ability is supposed to be reserved to when sudden braking for a stop is needed.

As for casualy braking in bends. I wouldn't brake in a bend for no particular reason. I might brake into a bend gently as the steering goes in, in what is called trail braking. I used to think that it enhances grip. Today I realise that it is better to negotiate a bend at a steady speed of 20mph instead of decelerating into it from 22mph down to 20mph.

However, since while trail braking we are losing speed, than the car's stability while trail braking will be lower than if you would negotiate the same turn at the same speed on constant throttle. This makes the question of whether or not to brake into a bend somewhat philosophical.

Since drivers tend to enter a bend at a certain speed which feels comfortable, than I find it better to slow down gently into the bend from that speed into a slightly slower speed mid-bend. This has the additional advantages of a quicker steering response and more steering feel along with faster brake response times for sudden braking.

[Kimosabe]

Okay so it's the AD way to go in slow - fast out, with a constant speed around a corner.

[jcochrane]

Okay so it's the AD way to go in slow - fast out, with a constant speed around a corner.

Slow in fast out I agree with but rather than constant speed I prefer to match speed to the limit point. So if the limit point increases then I would increase the car's speed to match it. All other things being equal. If the limit point decreases then I would decrease the car's speed to match it.

As an exercise focus on the limit point on the approach to bends and you'll notice how often and early the limit point will start to run more often than not before steering input is required.

[TripleS]

Okay so it's the AD way to go in slow - fast out, with a constant speed around a corner.

That, in total, sounds a bit tricky to me.

[Silk]

Okay so it's the AD way to go in slow - fast out, with a constant speed around a corner.

That, in total, sounds a bit tricky to me.

It's easy enough to do it. The problem is managing the expectations of following drivers who expect you to do what they do, which is to leave everything to the last minute and hope for the best.

[kfae8959]

I think Triple is reflecting on the logic, not the practice!

David

[Silk]

I think Triple is reflecting on the logic, not the practice!

David

Who knows what goes on in that mind of his?

[TripleS]

I think Triple is reflecting on the logic, not the practice!

David

Who knows what goes on in that mind of his?

Eileen's had the same problem - for above 50 years! She remains mystified to this day.