Steering input

[Astraist]

On many discussions here and on the old fora, we tend to get back into the subject of steering input. So, just like I did there, I will sum up my thoughts about what steering inputs correlate with what steering outputs, and hopefully put an end to this otherwise endless debate.

So, I am not writing this because it is a particularly important subject, I am writing this because it isn't and we would be better it off putting it to rest here and than resume bantering on more important subjects.

To think that there is absolutly no correlation between steering input and steering output is untrue. There usually are gains, however little, to be reaped from improving the Human-Machine interface. So it's something I do work on, rather than trying to transcend it entirely from the outset.

I will look into how the elements of a steering style can be made to fulfill our requirements for percision, smoothness, consistency and effort-reduction. These elements, however, are not unique to any particular style: Each style is in essence a different compromise between them all.

But before I do that, I think we need to put whatever amount of fixed-input steering that we do outside of the discussion. Fixed-input is too generic to be a "steering style". You just hold the damn thing and deflect it.

Within a reasonable range of motion, fixed-input is the ideal way to steer. Generally, it's ideal to do it with the hands across the diameter of the wheel rather than across a chord, but in the very extremes of shoulder breadth and steering wheel diameter, putting the hands slightly higher might be better.

Accuracy
Accuracy requires both hands. With a single hand, the weight of the hand acts on the wheel so that it works against turning it "up" and the driver needs to compensate with more shoulder strength. In the "down" direction it falls with the steering. In both cases there tends to be a bit too much steering going on too quickly.

When another hand is on the wheel in any way, it creates friction that counteracts some of that added weight and the steering tends to be more accurate, amongst other things.

Accuracy generally improves with the pulling hand. Even if it is initiated from across the wheel (as with rotational and other styles), the pulling motion is still generally one towards the body rather than away from it. It utilises many more muscles, both slow-twitch and fast-twitch.

The only problem with the pulling hand is in it's final range of motion - towards the bottom of the wheel. Ultimately the arm's motion is limited by the torso, the forearm supinates and the wrist becomes twisted, which hampers accuracy. Pull-push in particular tends to suffer from that.

Smoothness
Steering smoothness drops as the input is split up into more pieces. Every switching from guiding the wheel with one hand to another decelerates and than accelerates back the rate at which the wheel is rotated. With either Pull-Push or rotational we want each guiding hand to "bite" as much steering movement as possible.

Effort
You wouldn't want steering to require more effort than it absolutely must. A lot of one-handed steering stems from that thinking, but it is in fact self-defeating because more muscle needs to counteract the weight of the hand when steady and particularly when in motion.

Pulling, even if it's not with the aid of gravity, again helps with reducing effort compared to pushing. Anyhow, you'd want each movement - pulling or pushing - to be as long as possible rather than having to stop and reinitiate the motion many times over a single input.

You also want symmetry between how you turn into the corner and how you remove steering lock, so the effort is distributed 50-50% between both hands, even if the road curves mostly in just one direction, which it would in, say, a road going around a mountain.

Consistency
Being consistent is mainly about ensuring control even in the event of steering kick-back. You wouldn't want it springing out of your hand over a bump in a corner. To achieve this, two hands should be on the wheel (even if only one is guiding it at any given time) as long as possible.

At least one hand should grip the wheel rather than be pressed on to it, as is the case with the hand not guiding the wheel or with the hand that is guiding it in the case of palming. Pull-Push is good in terms of having a more secure grip.

Consistency is also about readiness. Most of our inputs on the public road should be quite slow in terms of rate, but we do need to be capable of applying lock quickly while still staying as smooth, accurate and effortless as possible. Rotational can be good that.

It's desireable than, to have the hands settle after each steering input back into a position roughly across the diameter of the wheel, so that fixed input can be used for adjustments or big, sudden deflections, if needed.

Safety
Starting a steering motion from across the diameter of the wheel in order to get a big "bite" of steering has the disadvantage of putting the hand in the way of the airbag, but I think we can all agree that this is a reasonable compromise.

If you look at the speed in which we need steering inputs of more than 90 degrees of lock it's normally below the threshold of airbag deployment anyway, and in any case were are only vulnerable at the very start of the motion.

True, another driver might hit us at speed, but it's one area where I am happy to sacrifice some secondary safety for primary safety. After all, primary safety can also dictate the fate of others around us - in our car or in another.

One thing some people do which is hazardous is hooking the entire hand inverted on the inside of the rim to rotate it. Very limited in motion it is, too, and it also uses far too much effort. There are issues with smoothness in switching hands in this fashion, and with consistency because failing to draw one hand out of the wheel can arrest it's motion.

What I do
Personally, I use fixed-input for any input less than 90 degress of steering in a car wheel, and slightly less in a more planar wheel (as in lorries). When a greater input is needed, I simply extend the range of motion available for fixed-input by predictivelly prepositioning the hands against the direction of the bend.

Because prepositioning both hands is also very limited in range, I tend to preposition just the hand in the direction of the bend and keep the opposite hand where it was. I pull the wheel as if I "draw" it out from the opposite hand so that mid-corner I fall back into quarter-to-three. I than preposition the opposite hand to remove the steering lock and fall back to the basic hand position again.

In order to achieve the greatest range of motion, I am happy to preposition the hand around and under the wheel. It's not palming, but gripping the face of the wheel with the palm pointing down. The hand than slips under the opposite hand and across the wheel so one can apply 270 or 360 degrees of steering in one "go." Here's a good example of it all:

https://www.youtube.com/watch?v=NgDK4wiZJ_M

So I get smoothness for using the longest possible hand motions and using either the pulling hand or bot hands together in a fixed-input. I get accuracy and effort reduction for much the same reason, and I am also consistent because both hands are on the wheel at all times and at least one is gripping it at any moment.

However, if you look at what we established is needed for effective steering, it's not unobtainable with any of the other steering styles, be it rotational, pull-push or whatever.

[titian]

You may be aware that the IAM Roadsmart are in the process of updating their Skills for Life course material, one of their objectives is to bring the training up to date, acll it "real world".

The IAM's advice on steering is now:-
• Hold the steering wheel in a way that allows for a full and accurate range of movement - Maintain a light grip, ready to exert a tighter grip if required - Keep arms slightly bent to prevent accidental movement of the steering wheel
• Demonstrate a smooth steering action which allows for easy use of the other controls - Use a steering method that is comfortable and allows for a full range of movement with little physical effort - Pull-Push steering enables safe and efficient use of other controls - Fixed grip steering is an option for smaller movements of the wheel as long as the arms don’t cross - Advanced drivers should also be aware that a comfortable seating position is important for accurate steering
• Steer the vehicle accurately to maintain a stable, safe and appropriate course with the capacity to change direction, if required - Advanced drivers should be aware that the type of vehicle, any power assistance and the mechanical set up may influence their steering method - A straight course should require little or no steering input.

As in all things driving, SAFETY is of primary importance, however the IAM stance has moved towards "if it isn't broken, don't fix it" which in this context means don't spend inordinate amounts of observing time and effort in trying to change the Associate's steering method so long as it is safe, smooth and consistently acurate, they go on to say that so long as observers achieve the desired outputs, the inputs ought not to be changed.

It has been said though that in the case of Masters, a student would find it difficult to pass without a fundamentally sound style of pull/push steering, hearsay?

[Astraist]

Admittingly, I was not aware. Not least because I coach outside of such frameworks as the IAM, and indeed outside of countries where such frameworks exist...

All I do is helping myself and helping others around me in becomes the best drivers they can. Given the time, I always like to help drivers develop their competence on all levels, including the human-machine interface.

In the context of the discussion on this board, what I tried to do is to get a relatively insignificant but still noteworthy subject summed up, so that we don't have a hundred threads degenerating into discussions on steering methods.

[martine]

So you are happy putting your hand/wrist/lower arm across the airbag during some steering?

I use a combination of fixed grip and pull/push for larger movements.

[Astraist]

I am.

Ultimately, you cannot entirely avoid the possibility of hand injuries. The volumes of airbags vary between cars and hands placed even at just 11 O'Clock (wheel as clockface) can be injured. There can also be hand injuries unrelated to the airbag.

The speed in which I cross my arm over are well below the threshold of airbag deployment, and frontal airbags don't tend to deploy when the collision is at a substantial angle away from straight-ahead anyway.

There is of course a chance for spontaneous deployment, but that has become quite rare. Newer cars also have variable velocities of airbag deployment which reduces injuries.

Anyhow, since I pull the wheel back (see video), the hand doesn't stay there so it might be better than the way some people shuffle or cross hands in quick succession over the top of the wheel so their hands are exposed throughout the entire corner.

And, eventually I also find this to be a place where one needs to compromise between primary and secondary safety. For me, secondary safety is secondary for a reason.

It's also part of why I normally do use my thumbs as leverage over the spokes of the wheel.

[Horse]

So you are happy putting your hand/wrist/lower arm across the airbag during some steering?

The airbag will [almost certainly, in normal driving] not go off unless there'sa frontal impact. So if this technique isn't used if there's the chance of that type of crash, then where's the problem? Just make choice of appropriate method part of planning.

[Mr Cholmondeley-Warner]

Can I make a plea? Can we PLEASE not derail this thread into (yet) another discussion of the IAM and its standards. If this happens, I can and will remove posts, or move them to the IAM forum where they can be dissected into tiny pieces by the IAMists.

[waremark]

"So, I am not writing this because it is a particularly important subject, I am writing this because it isn't and we would be better it off putting it to rest here and than resume bantering on more important subjects."

And then you include some fairly prescriptive thoughts with which others are bound to disagree! Happy to read your thoughts (I generally appreciate your inputs - ha ha! ) but don't know why you think they could close down the topic.

[Astraist]

My point wasn't to avoid discussion, but rather to give a sense of priorities.

There are lots of people here who seek to transcend the human-machine interface entirely. I don׳t, but overall I agree it isn't all that significant to how one drives.

And outside of my description of how I steer, I can't see anything particularly prescriptive. I suggested how I personally steer mainly to provide an example that isn't rotational or pull-push, and show how it is in accordance with the objective criteria for good steering which I have explained.

[waremark]

My point wasn't to avoid discussion, but rather to give a sense of priorities.

There are lots of people here who seek to transcend the human-machine interface entirely. I don׳t, but overall I agree it isn't all that significant to how one drives.

And outside of my description of how I steer, I can't see anything particularly prescriptive. I suggested how I personally steer mainly to provide an example that isn't rotational or pull-push, and show how it is in accordance with the objective criteria for good steering which I have explained.

I take most of my comment back - not particularly prescriptive, and I agree about priorities. My main point was really amusement at following this with a detailed post on steering:

"and hopefully put an end to this otherwise endless debate".