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 Roadcraft
 Roadcraft, an introduction
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Nigel A
Male Junior Member
68 Posts


TAUNTON, Somerset
United Kingdom

(None)

Formerly BMW 80RT

Posted - 06/10/2009 :  1:04 AM
rioguy and gymnast seem to be pretty much on the mark. And it is interesting now that they are exploring limit point.

A key point coming out of their remarks relates to being able to stop (at all times) in the distance you can see to be clear. What that really means is that there might be a hazard or potental threat present in a shorter distance than you can actually see, so the 'see to be clear' bit is important. What this also means is, as referred to in their comments, that there are basically two speeds for going through a bend. One is just within the physical limitations of grip, which is what would be done on a race circuit. And the other is a speed so that you can stop in the distance you can see to be clear. The two are quite different. And since we are dealing with safety being paramount only the second is relative in road conditions.

Roger asked about the difference between open and closed bends, which comes from the item on positioning. A closed bend is one which you can not see across, and an open ben is one where you can. An exteme example of an open bend is on a racetrack where the road all the way through the curve and on out the otherside can be clearly seen. In these circumstances, should they happen on the road, then the speed for the bend might be up to the limit of adhesion since the view is so long and the rider could still stop in the distance he or she can see to be clear.

To really apply limit piont well it is also necessary to understand the principles of positioning (since that also affects the extent of view) and also have the item on dealing with bends. This will lead to an understanding of the deep entry, shallow exit principle and what you call late apex cornering. Well, it's not actually that because the apex is the centre of the curve of the bend. What is actually being said is that the point at which you come closest to the inside of the curve is behind the apex. That point is (and, yes, it is a racing term) called the 'clipping point'. So, in the deep entry, shallow exit approach to bends the clipping point is behind the apex. Walter Honneger's book, already mentioned, goes into this very well.

As indicated by gymast's and rioguy's comments undertanding and applying limit point is the key getting (and even adjusting) speed in a bend. When I am working with associates (those training to get to the standard for their advanced test) I get them very focused on limit point and at the higher levels, where they miight be driving more progressively, there is a an important clue as to when the bend is starting to open out (assuming closed bends - open bends you can see beyond the curve anyway). That is the initial but very subtle start of the limit point moving away from you. And you have to really focus to get it right. I am often saying 'tune into the limit point' so that they pick up that very first indication of the bend straightening and can adjust the the steering and power (throttle) accordingly in preparation for the bend fully opening out back on to a straight (for example).

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rioguy
Ex-Member

Posted - 06/10/2009 :  5:14 AM
quote:
That is the initial but very subtle start of the limit point moving away from you


Aside from the safety aspect of not hitting anything in a curve, this was the biggest breakthrough for me. As soon as the limit point starts to move away, I started gradually accelerating to the speed limit. It happens earlier than the point I used to accelerate.

As Nigel pointed out, the things we have discussed elsewhere about delayed apex turns still apply.
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Nigel A
Male Junior Member
68 Posts


TAUNTON, Somerset
United Kingdom

(None)

Formerly BMW 80RT

Posted - 06/10/2009 :  5:30 AM
Delighted to read, rioguy, that limit point is being so benificial for you.

In the thread I think we next need to get into positioning (that is lateral positioning and all that that encompasses) since, in many ways, the two are interwoven. But to have a fully interactive exchange on the thread I think more people would need to have the article on Safety, View and Stability, The Principles of Positioning.

rioguy and gymnast have both had these items so I look forward to their comments on the subject.
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rioguy
Ex-Member

Posted - 06/10/2009 :  6:26 AM
Safety, view, stability

For the moment, I'll just focus on view although it does not act independently of the others. The concept comes from page 47 of Motorcycle Roadcraft. The interpretations are mine and open to discussion. There is no "right" answer, just choices should be conscious.



Approaching an intersection, one has a choice of the left, right or center position in a lane. One of the things that influences this choice is the view. The rider should strive to be able to see hazards as soon as possible so they can react and stop prior to an exchange of energy. Finding out these zones is better found on the computer at home than by accident. (Pun intended.) After studying them, consciously practicing them will increase proficiency.

The red rider misses anything that might be in the red zone. The green rider has an increased view. However, the red rider has a better view of cross traffic to the left. As one approaches an intersection, they would be well advised to consciously select a position based on what views need to be gained and what views are unobstructed.

This is just a specific example of a case that demonstrates a general rule. The general rule is that positioning affects visibility. One should strive to maximize visibility by moving left or right in their lane if there are no other factors that would make a position more hazardous. For instance, if there were crossing traffic from the left and my view was unobstructed to the right, I might choose to move right to become visible sooner.

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scottrnelson
Advanced Member
6884 Posts
[Mentor]


Pleasanton, CA
USA

KTM

990 Adv, XR650L

Posted - 06/10/2009 :  7:24 AM
quote:
Originally posted by rioguy

Approaching an intersection, one has a choice of the left, right or center position in a lane. One of the things that influences this choice is the view.

I'm just curious. Do they put buildings right up against the edge of the road where you live? Around here, if I'm first in line at just about any intersection I can usually see several hundred feet in each direction regardless of where I am in the lane. I'm trying to figure out when your diagram with the red and yellow sight lines would come into play.
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rioguy
Ex-Member

Posted - 06/10/2009 :  7:53 AM
quote:
Originally posted by scottrnelson

quote:
Originally posted by rioguy

Approaching an intersection, one has a choice of the left, right or center position in a lane. One of the things that influences this choice is the view.

I'm just curious. Do they put buildings right up against the edge of the road where you live? Around here, if I'm first in line at just about any intersection I can usually see several hundred feet in each direction regardless of where I am in the lane. I'm trying to figure out when your diagram with the red and yellow sight lines would come into play.



Scott,

As we go through these situations, there will be differences of opinion based on our interpretation of the diagrams and how we picture the real world situation. Please try to keep in mind the root concept is to maximize visibility if possible by lane positioning.

The picture does not depict a rider at an intersection. It's a rider approaching the intersection. Perhaps I could have put the bikes farther from the intersection to illustrate the point correctly.

This process will work best if we discover the root concepts, then go out and find applications of the root concept. Then come back and post them. What you post may help another person to develop the root concept and apply it to their particular situation. Being passive in this process doesn't work.

The end goal is even higher. It's for all of us to ride more consciously and proactively avoiding hazards before they develop into a situation where we need skills. It goes even farther than that. It's one thing to avoid crashes. It's quite another to avoid even a minor condition that has a remote possibility of leading to a crash. If a condition has a one in a million chance of causing a crash and it is repeated often enough, ultimately that condition will lead to a crash for someone.

Some of the concepts practiced in Roadcraft may be hazardous to the newer rider who still needs to focus on more basic skills. However, unless one is willing to make the effort to progress beyond their current level, they will never progress. The cost of this lack of progression could be a pound of flesh.
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rioguy
Ex-Member

Posted - 06/10/2009 :  9:17 AM
Safety, View, Stability

This is a very complex situation, but those who ride in cities can almost certainly expect to see something similar. The distances are compressed in the diagram.



Imagine that you are the rider at the bottom of the picture on the green bike. Because you are gathering information by looking far ahead, you recognize the solid red vehicle will almost certainly encroach on your lane.

In order to improve SAFETY, you move to the left as he starts to encroach or before he encroaches taking the position of the solid red bike.

However this creates another problem. The red dot is a pedestrian between the two vehicles on the left. As you go forward, you will be in the position of the dashed red bike. Note how much later the dashed red bike can see the pedestrian than the dashed green bike. You have lost VISIBILITY.

Let's make this one multiple choice (multiple answers allowed):

If you were in the position of the solid green bike,

1. I'd continue in the right tire track, demanding the oncoming vehicle respect my right to the lane.

2. I'd move to the left tire track while maintaining my speed.

3. I'd move to the left tire track while slowing down.

4. Something else - please explain.

What other things would you be thinking about in this situation?

General rule: If a situation requires me to reposition in an area where I can no longer stop in the area I can see, slow down. To make it even broader, when there is a situation that will compromise safety, visibility or stability, slow down before the compromise occurs.

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James R. Davis
Male Administrator
17295 Posts
[Mentor]


Houston, TX
USA

Honda

GoldWing 1500

Posted - 06/10/2009 :  9:20 AM Follow poster on Twitter  Join poster on Facebook as Friend  
The intersection example shown demonstrates ONE ASPECT of the situation (view) as a consideration, to be sure, but it is misleading on its face and it provides a false focus. In essence, when the topic is large, focusing on a tiny aspect of it is to my mind a disservice.

For example, the large topic attempted to be reduced to manageable proportions by this graphic is known to most of us as 'SITUATIONAL AWARENESS' yet the graphic portrays a TINY aspect of that topic and makes it seem to be the essence of the larger topic.

It is helpful in an extremely limited way - much like saying, 'the way you spell view is 'V', 'I', 'E', 'W'. If the most important aspect of situational awareness is how to spell certain words, it has value, but if the concept of 'visibility' or 'sight lines' is what you want the reader to focus on, then showing what might obstruct you from seeing (or being seen), the graphic does that relatively well. My concern here is that 'situational awareness' is hugely more than sight lines (view) or even 'positioning' and focusing on one or the other tends to obscure the larger picture.

For example, if that south-west corner is a building as shown, you have NO BUSINESS AT ALL simply riding through that intersection - you need to essentially stop and do a head check before going through it. If that is a lighted signal intersection, you need to know what the colors of those lights is and have a pretty good idea of how 'stale' those colors are. And, regardless of the signal light colors, you need to have a good idea of what that vehicle to the left is doing (speeding up, slowing down, unaware of the light he is approaching). And, if there were no lights or stop signs at that intersection, the very presence of a vehicle in either the yellow or red areas argues that you need to STOP, not go through the intersection.

You also need to have scanned to the left AND right and determined if on the sidewalk on the right (hidden now by sight line) there is a dog running toward the intersection, or a child on a skateboard doing the same thing.

The diagram argues 'positioning' more than 'view', though it uses 'view' as input to the 'positioning' decision. And that is yet more reason to deal with the larger topic of 'situational awareness' - its components are not independent from each other.

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scottrnelson
Advanced Member
6884 Posts
[Mentor]


Pleasanton, CA
USA

KTM

990 Adv, XR650L

Peer Review: 1

Posted - 06/10/2009 :  9:39 AM
quote:
Originally posted by James R. Davis

The diagram argues 'positioning' more than 'view', though it uses 'view' as input to the 'positioning' decision. And that is yet more reason to deal with the larger topic of 'situational awareness' - its components are not independent from each other.

I agree with what James has said.

As I was riding in to work this morning I was thinking of this diagram as I passed each of the 11 intersections on the way. My conclusion was that if you're moving at the time, your lane position is very insignificant in regards to how quickly you can identify a threat coming from a side street. Being all the way to the left or all the way to the right of my lane gives me an advantage of one or two feet of forward travel at the most as to what I can see coming from a side street. To keep the numbers nice and round, at 27 mph I travel one foot in 1/40th of a second. So being all the way to one side or the other gives me at most 1/20th of a second advantage in seeing something sooner. Going faster gives me less time advantage.

In my opinion, paying attention to such a small detail as that at the possible expense of other aspects of situational awareness might actually reduce overall safety. I'll be the first to agree that lane position can make a big difference on blind curves in the hills, but I happen to feel that it makes an insignificant difference to my ability to identify a threat on city streets.
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rioguy
Ex-Member

Posted - 06/10/2009 :  9:59 AM
Scott,

Thumbs up for trying it.

After your post, I went out and did a little experiment. I went out to the intersection on the corner and walked down the right tire track while using a Stop sign as a site along the sidewalk on the other side.

It made a difference of about 30 feet of the distance I could see on the sidewalk on the other side. That difference could allow me to pick up a jogger on that sidewalk sooner in the left tire track than the right tire track. But don't get hung up on this situation. Most times it will be insignificant.

Keep in mind the general rule that our lane position can at times significantly affect the areas we can see.

James, I'm not suggesting situational awareness is unimportant. My cross-check is very linear, almost computer like. I look consciously for a fraction of time in areas where hazards occur. I build this into a mosaic of the entire picture. I've spent a lot of time just standing on the side of the road and looking for the particular things I need to look for in different situations.

There is a good picture showing this on page 16 with the following quote.

"Our ability to handle information about the environment is limited. We cope with this by giving more (my addition, not ALL) attention to some parts of the environment than others and concentrating on them. This is important in riding because we react most quickly to things happening in the part of the environment on which we are concentrating.

One way of seeing this is to imagine your field of view as a picture - you can see the whole picture but you can only concentrate on one part at a time."

It may be that after looking at all the hazards in an intersection, you develop a rule of thumb for lane position in this type of intersection.


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James R. Davis
Male Administrator
17295 Posts
[Mentor]


Houston, TX
USA

Honda

GoldWing 1500

Posted - 06/10/2009 :  10:09 AM Follow poster on Twitter  Join poster on Facebook as Friend  
I certainly understand what you are saying, though I tend to disagree with it.

As I have explained many times on this site, you have a finite amount of attention that you can 'spend'. That is, if you 'PAY' attention to something you cannot pay attention to something else. That is exactly the wrong methodology, to my way of thinking, to obtain an appropriate level of situational awareness. Instead, I believe, one needs to be consciously ALERT. The more attention you pay to anything, the less alert you are generally.

In the real world there is constant and UNEXPECTED, indeed UNKNOWABLE IN ADVANCE, change all about you. That argues that you MUST NOT 'spend' a good portion of your conscious mind focused on any particular aspect of it if you hope to be able to recognize and respond to anything else that MIGHT become a threat. To do that you must be UNFOCUSED and receptive to all of that environment - which is called being ALERT, not 'paying attention'.

When something becomes a thread, that is the time you must 'pay' attention to it. And when you do that, you have become myoptic and unable to recognize other things, generally, that might still become threats. So, in my opinion, you 'pay attention' to things with great caution and reluctance while riding a motorcycle.

The 'awareness' in situational awareness is BROAD based while paying attention is focused.
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rioguy
Ex-Member

Posted - 06/10/2009 :  10:32 AM
quote:
James said:
To do that you must be UNFOCUSED and receptive to all of that environment - which is called being ALERT, not 'paying attention'.


I dislike it when my own concepts are repeated back to me. I've certainly said in the past that I like to ride with an empty CONSCIOUS mind.

Maybe the confusion is the words "Focus" and "Paying attention" suggest a long period of time. It's simply not what I'm trying to say.

To try to experience what I mean, I'd suggest riding in the city in mild traffic doing some commentary riding. Imagine you are making a video for me to watch.

You will likely find you cannot speak fast enough to name all the hazards you see. The things you say will actually be AFTER you noted a hazard, made a decision and went on to something else. Watching the video, you might not mention a pedestrian approaching a crosswalk and instead mention a car just past the intersection. Perhaps you determined the pedestrian wasn't a threat and decided to PRIORITIZE the hazard of the car into your conscious mind. This doesn't mean you disregarded the pedestrian. You just set a higher priority on the car as it was more of a threat while simultaneously monitoring the pedestrian.

One of my early instructors described what you are calling "Focus" as "Stepping on piss ants while the elephants are running over you."



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James R. Davis
Male Administrator
17295 Posts
[Mentor]


Houston, TX
USA

Honda

GoldWing 1500

Posted - 06/10/2009 :  11:15 AM Follow poster on Twitter  Join poster on Facebook as Friend  
Actually, I think I used your referenced words and concepts, not yours.

quote:
"Our ability to handle information about the environment is limited. We cope with this by giving more (my addition, not ALL) attention to some parts of the environment than others and concentrating on them. This is important in riding because we react most quickly to things happening in the part of the environment on which we are concentrating.


Unlike the way computers work - single thread, for the most part - your mind is a hugely parallel pattern recognition machine that is largely independent of the context in which those patterns exist. Your mind can EASILY recognize a threat emerging out of all the unrelated BROADBAND input it receives, so long as it is not constrained by 'concentrating' on other things. Prioritizing those threats is also part of their recognition, not requiring a concentrated effort on your part. When you hear a gunshot you duck - without deciding it is the most important thing to do (though by the time you hear it ducking is useless). When you see a car running a red light in an intersection you are approaching, you reach for your brake lever without prioritizing that reaction. If, on the other hand, you are concentrating on the vehicle approaching from the left and prioritizing its threat level, you might not even see the one from the right that is running the red light.
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rioguy
Ex-Member

Posted - 06/10/2009 :  11:26 AM
If a person who doesn't know the sound of a gun hears it, they are not likely to duck. At some point in their life a person has to learn the sound of a gun and the response. You are correct that ducking is not a useful response. But if I hear a pop,zing, I know they are firing my direction and a second shot is likely.

Maybe this perfectly describes the concept of learning things in our conscious mind, planning a conscious response and then relegating it to our unconscious mind after we learned it consciously.

One thing we are both doing is straying from the original premise that the distance we can be seen and see is affected by our lane position. This is a branch concept from a lower root of "Observation."

Any comments on the second diagram I posted?

A side note: The book is written in English. Sometimes it takes considerable effort to translate it and determine what word an American author would have used. It's really quite fun. In context, I don't take concentrate and pay attention as meaning an extended, undivided attention. More on the level of noting something or a glance.

Edited by - rioguy on 06/10/2009 11:33 AM
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rkfire
Advanced Member
1688 Posts


Stratford, CT
USA

Suzuki

Bandit

Peer Review: Blocked

Posted - 06/10/2009 :  11:30 AM   Join poster on Facebook as Friend  
Nigel, thanks for the explanation of closed/open curves. I assumed it meant something other than blind curves, because if memory serves me, the article also used the term blind curves.

Scott, in my neck of the woods, there very well might be a building at times right on the side of the road or intersection, there may be tall brush or hedges, or just the geography with rock or a mound of soil. Not everywhere of course, but not uncommon.

Looking at that intersection diagram, I'd want to know what the traffic control is. If it were controlled by signal lights, and I had a non-stale green light then I would be left or right center probably, just to be off of the potentially slick center of my lane. If it had stop signs for the intersecting roads, and none for me, I might position myself to the right for a stopped car at the left, or to the left for a car stopped to the right. That choice would be to give the other car an opportunity to see a longer VIEW of my headlight, as much if not more than for my view of the them.
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scottrnelson
Advanced Member
6884 Posts
[Mentor]


Pleasanton, CA
USA

KTM

990 Adv, XR650L

Posted - 06/10/2009 :  12:12 PM
quote:
Originally posted by rkfire

Looking at that intersection diagram, I'd want to know what the traffic control is. If it were controlled by signal lights, and I had a non-stale green light then I would be left or right center probably, just to be off of the potentially slick center of my lane. If it had stop signs for the intersecting roads, and none for me, I might position myself to the right for a stopped car at the left, or to the left for a car stopped to the right. That choice would be to give the other car an opportunity to see a longer VIEW of my headlight, as much if not more than for my view of the them.

Rioguy keeps trying to move us along to his next point and we just won't leave this one alone.

If you feel that your left/right lane position makes a difference in how soon you can identify a threat, wouldn't it make sense to be in the best position to spot the earliest threat, which would be coming from the left side? So that would put you in the right part of your lane, right?

I still don't believe that lane position makes a significant difference in how quickly I can identify hazards at intersections, but I definitely look left before I look right when going across an intersection, because I'll be crossing the lane coming from the left before the one coming from the right. What I actually do when crossing an intersection is look left, look right, look left again just to be sure, then look right again one final time.
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rkfire
Advanced Member
1688 Posts


Stratford, CT
USA

Suzuki

Bandit

Peer Review: Blocked

Posted - 06/10/2009 :  12:26 PM   Join poster on Facebook as Friend  
Geesh, sorry, but I viewed the number of recent posts just now..lol.

Scott, I'm not really talking about the obstruction in that particular diagram, but only about my positioning to enable a stopped car on the cross street to have the best opportunity to see me before they might pull out.
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rioguy
Ex-Member

Posted - 06/10/2009 :  12:32 PM
Actually, there was no "next point." Both diagrams were examples of the SAME point. That a person's position in the lane affects how much they can see and be seen.

Scott, it may be that in your opinion, the earliest threat will come from the left. If there is a potential left turner and a clear view on the right, I'd certainly consider moving right. It really depends on the characteristics of the particular intersection you are approaching. Any of the three positions, left, right, center or any intermediate position might be appropriate. The key is to recognize the benefits and limitations of each position.

The Roadcraft System includes

Information
Position (both lateral and distance from vehicles ahead and behind)
Speed
Gear
Acceleration

I chose to focus on Position. Once one understands how it is possible for position to affect visual range, then they can back it up a step and know what Information to gather before an intersection.





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(Deleted or Lost)

Posted - 06/10/2009 :  12:41 PM
quote:
Originally posted by James R. Davis

In the real world there is constant and UNEXPECTED, indeed UNKNOWABLE IN ADVANCE, change all about you. That argues that you MUST NOT 'spend' a good portion of your conscious mind focused on any particular aspect of it if you hope to be able to recognize and respond to anything else that MIGHT become a threat. To do that you must be UNFOCUSED and receptive to all of that environment - which is called being ALERT, not 'paying attention'.




In the spirit of "agreeing in different words sometimes allows a third person to 'get it'".
I think I posted in another reply on here
"Focus - No Focus."
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Nigel A
Male Junior Member
68 Posts


TAUNTON, Somerset
United Kingdom

(None)

Formerly BMW 80RT

Posted - 06/10/2009 :  4:56 PM
Just looking at rioguy's illustration on positioning for a junction. The variation from the illustrations in the original Roadcrafts is that they were principally concerned with the threats which came from the nearside (for us the left; for you the right). Therefore the illustrations only related to potential threat from a nearside junction (intersection to you!). You will know better than I to what extent offside threats from junctions are real or imagined. Regarding off-side threats, the major concern in the UK is on-coming traffic up to or over the centre-line (maybe because they were overtaking a cyclist). My perception is that in general our roads are much narrower than yours so that, probably, positioning becomes more critical and, maybe, more important. I await your (anyone's) comments on this.

Our viewpoint about off-side junctions is that because you are on the opposite side of the road you have plenty of space between you an any potential hazard and also, your view will open up earlier in any case.
But, again, you are the best people to comment on how much of a real threat that is for you - dependant on the general driving/riding behaviour. But if people are really likely to dash straight across a junction from the other side then, in my book, you really do have issues to deal with.

You will appreciate that as we move along this thread that I am also learning what the general trend in driving/riding behavour is in the States. Out of interest, is it in Florida that they will procecute for any sign of aggressive driving behaviour? If so that's no bad thing
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