Curious coroner's remarks.

[Origamist]

[QUOTE 3681830, member: 9609"]@McWobble
I have found my figures, from 30mph on the bike I done two tests one 28m and the other 26m. I made one attempt in the van and had wrote down 6m (which is nearly a metere longer than the van! It wasn't the most scientific of tests, the speedometer probably wasn't very accurate (that van over read distance by 7.9% so the speedo probably did too) and I just paced out the stopping distances, so lots of room for errors!, but I do recall being suprised at how quickly the van had stopped and particularily that it had done so pretty much within its own length. I sort of suspect a decent car would perform better.[/QUOTE]

It's the overall stopping distance that is crucial - not just the braking distance. At 30mph thinking distance (just spotting a hazard) can eat up between 7m to 10m on average.

 

[cd365]

I would have liked an explanation as to how the collision actually occurred. Did the pedestrian move into the path of the cyclist or was the cyclists line too close to the edge? With a head torch on the cyclist should have been able to see someone walking along. There are a lot of unanswered questions for me.

 

[w00hoo_kent]

It's the overall stopping distance that is crucial - not just the braking distance. At 30mph thinking distance (just spotting a hazard) can eat up between 7m to 10m on average.

But when comparing different vehicles it's irrelevant because thinking distance is vehicle agnostic. You'll add that 7-10m to whatever you are operating.

 

[Origamist]

But when comparing different vehicles it's irrelevant because thinking distance is vehicle agnostic. You'll add that 7-10m to whatever you are operating.

Not quite. Motorists can have an obstructed view of the road conditions ahead - sat navs, A-Pillars, wipers, visors, pine tree air fresheners etc which can hinder cognition, delay hazard perception and thereby extend thinking time.

On a bike, you have much better visibility - assuming you are looking where you are going and not staring at your cassette...

 

[w00hoo_kent]

Not buying that I'm afraid. Yes, a motorist eating a sandwich while chatting on the phone is going to take longer to react to something. But so is a cyclist stretching out their leg muscles after a taxing hill climb, or fiddling with their gillet zipper while fondling around for their next gel sachet.

Presuming the operator of the vehicle is doing so in a sensible and legal manner without distractions, they are going to have the same thinking time to process what is happening in front of them to the point where they decide they need to stop. How they stop depends on the vehicle, speed to start the braking process happening, efficiency of the various components at stopping the vehicle on that particular road surface. If you decide 'when I get to that pole I'll start braking', then the distance it takes to happen will be a reasonably fair example of you vehicles braking distance. Slightly exaggerated by the fact that you were probably in place to start the braking quicker than you'd normally be.

 

[Pale Rider]

A lot has been made in this thread of the coroner's remarks about breaches of the Highway Code.

I suspect he was referring to the rules for pedestrians which include walking on the right when there is no footpath.

Presumably, the cyclist clouted the pedestrian from behind.

Had the pedestrian been on the right and the cyclist on the left, even on a narrow road there would have been no collision.

https://www.gov.uk/rules-pedestrians-1-to-35

 

[Origamist]

Not buying that I'm afraid. Yes, a motorist eating a sandwich while chatting on the phone is going to take longer to react to something. But so is a cyclist stretching out their leg muscles after a taxing hill climb, or fiddling with their gillet zipper while fondling around for their next gel sachet.

Presuming the operator of the vehicle is doing so in a sensible and legal manner without distractions, they are going to have the same thinking time to process what is happening in front of them to the point where they decide they need to stop. How they stop depends on the vehicle, speed to start the braking process happening, efficiency of the various components at stopping the vehicle on that particular road surface. If you decide 'when I get to that pole I'll start braking', then the distance it takes to happen will be a reasonably fair example of you vehicles braking distance. Slightly exaggerated by the fact that you were probably in place to start the braking quicker than you'd normally be.

I listed objects that create blindspots for drivers - A-pillars in particular are known to hamper the field of view and this will indubitably affect cognition. I'm not sure what you are not "buying" into.

 

[w00hoo_kent]

I listed objects that create blindspots for drivers - A-pillars in particular are known to hamper the field of view and this will indubitably affect cognition. I'm not sure what you are not "buying" into.

I'll clear that up for you. I am not buying in to the concept that the thinking time is different depending on the vehicle you are doing the thinking in and I'm definitely not buying in to the idea that the best vehicle to be doing the thinking on is a bicycle.

You make a list predominantly of things that don't need to create blind spots for drivers and aren't necessarily in the vehicle, let alone in the sight line of the driver in an attempt to suggest that you think quicker on a bike because it is some (my take on your argument here) pure experience of transport with no possible distractions where you are at one with your environment (I agree it's probably somewhat overblown for effect) while in a car your life is full of distractions and obstructions to obscure and impede your ability to think about braking. It's pretty obvious it was spurious by the fact that when you want to continue the argument you keep the one thing that might actually hold water in an argument although while I agree A pillar design is an issue I'd say the HC is probably talking about braking in a straight line to avoid an object to the front when it talks about braking distances.

It's perverting the concept of 'thinking time' as part of the braking process. Your brain takes time to turn the fact that it has spotted something that it needs to brake for in to the process of braking and to start sending out commands to make all of that happen. It equates basically to your current speed expressed as a distance in feet. That distance isn't dependent on the vehicle that you are in at the time that you are deciding if to brake or not. If other things have been added to the vehicle, or your experience in operating it that add distractions then the time will increase, but the base time will be uniform across vehicles.

 

[Pale Rider]

There is a fair bit of assumption there.

As a statement of the bleedin' obvious, I can't disagree.

But it does all fit.

The coroner found the pedestrian bore some responsibility for his demise by walking on the 'wrong' side of the road.

It may also go some way to explaining why the cyclist faced no criminal charges.

Thus the coroner and the police have done their jobs correctly, and have certainly not been in any way anti-cyclist.

 

[glasgowcyclist]

Had the pedestrian been on the right and the cyclist on the left,

What do you mean? The pedestrian's right is the cyclist's left.

GC

 

[Origamist]

I'll clear that up for you. I am not buying in to the concept that the thinking time is different depending on the vehicle you are doing the thinking in and I'm definitely not buying in to the idea that the best vehicle to be doing the thinking on is a bicycle.

It's perverting the concept of 'thinking time' as part of the braking process. Your brain takes time to turn the fact that it has spotted something that it needs to brake for in to the process of braking and to start sending out commands to make all of that happen. It equates basically to your current speed expressed as a distance in feet. That distance isn't dependent on the vehicle that you are in at the time that you are deciding if to brake or not. If other things have been added to the vehicle, or your experience in operating it that add distractions then the time will increase, but the base time will be uniform across vehicles.

It's not. The speed at which you react to a situation is governed initially by how quickly you can perceive and then process the "hazard". If there are blind spots affecting how quickly you can identify a hazard, your thinking/reaction time is going to increase. Motorists have a more of these blind spots by dint of the metal cage that envelops them and the objects they choose to deploy in front of the windscreen.

The rest of your points about my so called "argument" are the product of a lively imagination...

 

[Wobblers]

[QUOTE 3681830, member: 9609"]@McWobble
I have found my figures, from 30mph on the bike I done two tests one 28m and the other 26m. I made one attempt in the van and had wrote down 6m (which is nearly a metere longer than the van! It wasn't the most scientific of tests, the speedometer probably wasn't very accurate (that van over read distance by 7.9% so the speedo probably did too) and I just paced out the stopping distances, so lots of room for errors!, but I do recall being suprised at how quickly the van had stopped and particularily that it had done so pretty much within its own length. I sort of suspect a decent car would perform better.[/QUOTE]

Well, I must confess I was being just a little flippant. But there is a more serious point - that most people seriously underestimate the distance in which they can stop in. As I said, 8.5 m is under perfect conditions: new tyres and unblemished tarmac in the dry. For more typical dry conditions, you need to add 20% to this figure. And then there's another 8 metres to account for reaction time. Realistically, you're not going to be able to stop from 30 in anything less than 60 feet. And usually it'll be more. Possibly much more. Braking is limited by the cohesion between tyre and road, not brakes - unless there's something very wrong with them!

 

[Wobblers]

As to which is more dangerous if it does actually hit you, then I don't think kinetic energy is the only factor to consider. Bicycles have lots of pointy sharp bits to impale you with in comparison to the average jelly mould car these days with their smooth rubber bumpers and gently sloping bonnets. Personally I wouldn't like to be hit by either one at 20 mph!

The bonnet on a car serves a purely aerodynamic and aesthetic purpose. It is very thin metal, and offers no protection from the very sharp, pointy and hot engine just beneath. Collision with those hard pointy objects is a major cause of injury in pedestrian collisions. And given the mass of the cyclist is likely similar to you, momentum transfer and thus maximum forces (which relates rather well to degree of injury) will thus be half what they would be in the case of a car.

 

[Wobblers]

But when comparing different vehicles it's irrelevant because thinking distance is vehicle agnostic. You'll add that 7-10m to whatever you are operating.

Untrue. It takes longer to hit the brake in a car simply because nerve impulses are slow, and take longer to reach your legs - that alone accounts for 0.25 seconds. You also have to move your foot further - especially if the cyclist is covering the brakes (which most road cyclists do anyway when they're on the hoods). In short, an alert cyclist has a very significantly shorter thinking distance than an alert motorist. The key, of course, is to be alert....