Safe following distance?

[PrincessBandit]

from my understanding the 2 second rul allows enough distance for you to react and stop before hitting the car/bike in front when they emergency brake. If they had a head-on collision i imagine they would almost instantaneously come to a stand stall. I doubt 2 seconds would save u there so good on ya for trying to blame the guys "following too close"

Unusual reasoning - what difference is there between hitting a vehicle that comes to an "almost instantaneous stand still" in front of you and one which is obscured or hidden from view around a corner. That is what riding to what you can see is all about. It is our preconceptions that a vehicle in front of us will continue to travel as they are that lead us into a false sense of security when getting too close behind them.

I think I know what you are trying say, but my understanding of the 2 second rule is obviously different to yours. My understanding is that is to allow you reaction and stopping/avoidance time for ANY problem in front of you, not just a leading vehicle to "emergency brake".

[smoky]

So you all going to ride with a safe stopping distance in front of you at all times?

So taking a normal bend in the road you will maintain about 100 meters clear visibility at 100klm/hr.
You will of course have to keep more than the 2 seconds stopping distance in a corner – stopping quickly while leaning over is bit more difficult, so I think you’ll have to observe about a 5 second rule to be safe.
Blind hills would be the same

Now actually go out and ride like that (honestly) on a back road, or any road off the main highways, you’ll find corner after corner after corner where you’ll be slowing down to ridiculous speeds and probably give up pretty quickly
Be honest here – I’ve tried it, I agree with the sentiment, I agree with the general principal, I agree that’s a good way to ride where practical, but to ride (or even drive a car) like that at all times I would suggest is not going to happen.

There is and always will be the unexpected, always expect something unexpected, but it will always catch when you’re not expecting it.
Bike failure, puncture, even on a straight bit of road some dick can pull out in front of you.
Bikes aren’t a practically safe form of transport – it’s a calculated risk
But then so is driving a car – just a lower risk

[Road Guardian]

Two seconds works for me, four when it's raining (but then my brains saying "it's ice, it's ice) leave too much and some fucknuckle in a cage will fill it up. Nana's live longer I reccon.

Yea I like you style, and yes, cagers tend to do stupid things, and don't think about other road users, and will fill the gaps like that.

[PrincessBandit]

Yeah, was thinking about what i posted just before and realised that it kinda fits more with the 12 second rule. Using the variety of "seconds" rules should minimise crashes. Even travelling around a corner how many people barge on round assuming that the way will be clear (which it is probably 99.8% of the time) and then massively go fuuuuuuuuuuuuuuuucccccccccccckkkkkkkkk when that .2% occurs.
As for cars shoving into your following distance each person uses their discretion as to how to deal with it, and yes it may mean on occasion just letting them do it, regardless of whether they're a dick or not.

[Manxman]

I generally conform to the 2 second rule, except when lining up to overtake (obviously).

However, this concept nearly cost me dearly yesterday (and, after a good night's, rest still don't think I am underestimating the situation) going up Haywards toward Porirua, when a truck decided that because he was indicating to overtake a slower truck in his lane, he had an absolute right to pull right into the (2 second) gap in front of me in the right hand lane (despite the fact that I'm travelling about 20-30kph faster than him in a line of orderly overtaking traffic).

Anchors were thrown out pretty fecken big time, as I was rapidly and just a liiiittle scarily forced into the good ole cheesecutters, and missed them by inches, before regaining full control. Fuppin good one.

:slap::slap:

Had I stopped to sort it out with him, it's probably fair to say blood would have spilled liberally....but he wisely back riiiight off (I overtook him and 'waved' animatedly on the way past), for the rest of the journey - which was actually quite pleasant, especially going around the Pauahatanui Inlet.

Now, I have to say that I have seen this a few times around Welly dual carriageways/motorways (ie people thinking that simply because they're indicating to move into the right lane, means that have a God given right to do so, regardless of the faster speed of traffic already in that lane), so perhaps I should have anticipated....but you just can't prepare yourself for every complete fecken feckwit manoeuvre on the road...

[bikemike]

I've been thinking about this recently. There is the issue of being able to stop in the distance you can see to be clear, when not following. I guess you use experience and judgement,limit point, or even the 2/4 seconds rules.
Back to simple following - no corners, not overtaking etc.

Two seconds is good because it's time based and expands as speed goes up. Without getting into how good that relationship is with the rising braking ditances - it's a good starting point - I found myself naming the shit that appeared as the car in front drove on....
Tar band, white paint, man hole, pot hole, litter, bottle, can, ball, newspaper, old tyre strip, dead cat etc.

If you are two seconds or more AND you can keep your eyes ahead AND name the thing that you see BEFORE you get to it, then you also account somewhat for the state of your mind as well as the speed of your bike. I know that language (generally) operates somewhere else in the brain to motor but, some account of cognitive speed is still there.

It's not perfect either, but on good days I can name stuff in two seconds. On bad days I pull back.
Anyone else tried this?

[Richi]

Unusual reasoning - what difference is there between hitting a vehicle that comes to an "almost instantaneous stand still" in front of you and one which is obscured or hidden from view around a corner. That is what riding to what you can see is all about. It is our preconceptions that a vehicle in front of us will continue to travel as they are that lead us into a false sense of security when getting too close behind them.

I think I know what you are trying say, but my understanding of the 2 second rule is obviously different to yours. My understanding is that is to allow you reaction and stopping/avoidance time for ANY problem in front of you, not just a leading vehicle to "emergency brake".

Yea i guess we must have slightly different understanding of it, next time im out on my bike I might try this and get a good idea of how far 2 seconds is at 100kmph then try and completely stop in that distance. I dont rate my chances maybe i underestimate the braking power!

[Jantar]

Yea i guess we must have slightly different understanding of it, next time im out on my bike I might try this and get a good idea of how far 2 seconds is at 100kmph then try and completely stop in that distance. I dont rate my chances maybe i underestimate the braking power!

Don't bother trying. Stopping from 100 kmh to 0 in 2 seconds is 1.4G. The very best tyres will only permit a 0.9 G decelleration under ideal conditions.

The 2 seconds following distance is to allow for reaction time and response, not to actually stop. You should be looking for hazards 9 to 12 seconds ahead to allow for both reaction and stopping distance.

[karla]

I got told a while ago that you should be able to have the car in frount stop dead and you be able to slow enough that you hare happy to hit it. Or avoid it etc. I think a shade (but bugger all) under the 2 second rule fits well.

Eek - I must have misread somewhere, or am overly cautious, 'cos I use the 12 second rule

Coming home from doing the Mainland Driving school advanced riding course a delivery truck I was following on the open road locked up his wheels for no apparent reason, and started skidding down the road in front of me.

It was lovely to be able to brake and slow down immediately, without panicking, without locking up the back wheel, and without hitting the truck. Certainly helps after having done a a few practice stops at 100ks per/hr on the racetrack.

[Richi]

Don't bother trying. Stopping from 100 kmh to 0 in 2 seconds is 1.4G. The very best tyres will only permit a 0.9 G decelleration under ideal conditions.

The 2 seconds following distance is to allow for reaction time and response, not to actually stop. You should be looking for hazards 9 to 12 seconds ahead to allow for both reaction and stopping distance.

I guess thats the point I was trying to make about being able to stop in 2 seconds is impossible. Im just not brainy enough to explain it properly

[R6_kid:Me]

Smoky, i see what you are saying. I know it doesnt happen 100% of the time in practice.

I'm not saying we should all be nannas and wear bubble wrap when we ride, this is simply a discussion to get people actively thinking about their following distances - whether it be from a truck/car/another bike is irrespective.

I would most likely be right in assuming that A LOT of 'accidents' would not happen if people observed better following distances from other vehicles. For instance, a Hyosung rider which a friend of mine helped to pull out of a ditch after he ran up the ass of the rider in front when they slowed down suddenly.

[swbarnett]

I think the point about being able to stop in your visibility when it comes to blind corners is a good one. I also accept that this seldom happens in practice. I know I'm slower on blind corners than equivalent clear ones. However, I'm probably still not slow enough to stop completely in my visibility. I suppose the point is that if you don't travel slow enough around blind corners and come to grief then you must accept at lease some of the blame for the accident.

[ElCoyote]

Do you understand the concept of being able to stop within the distance visible in front of you?

Actually isn't it half the clear distance ahead

[Katman]

Actually isn't it half the clear distance ahead

On a road with a marked centre line it's the visible distance in front of you.

On a road without a centre line it's half the visible distance.

It is the main thought in my mind everytime I take a blind corner - can I stop in the distance I can see?

Anyone who says you can't always ride like that, is talking bullshit. You can - and you should.

The one time that theory won't work is if someone in the oncoming traffic is overtaking another vehicle on that blind corner.

(Hey, that sounds like something motorcyclists have a wont to do).

[PrincessBandit]

Don't bother trying. Stopping from 100 kmh to 0 in 2 seconds is 1.4G. The very best tyres will only permit a 0.9 G decelleration under ideal conditions.

The 2 seconds following distance is to allow for reaction time and response, not to actually stop. You should be looking for hazards 9 to 12 seconds ahead to allow for both reaction and stopping distance.

Good point (second sentence) damned physics! - think I did say stopping/avoidance in my earlier post.

The use of the 12 second rule is often underrated by some people, they focus almost exclusively on the vehicle in front of them at the expense of keeping an eye out for what is further up ahead or beyond that vehicle. While the vehicle immediately in front is understandably of greatest concern due to it's proximity much avoidance of hazards can be countered by looking ahead of those vehicles as well.