A Personal Message to Critical Mass.

[CopperBrompton]

It's not a "16mph mechanism" - it is simply the concept of an optimum top speed for transport

If he is right that there is one, and that 15mph is it, then there is some mechanism that makes it so. Neither you nor he (from the linked piece, anyway) seem to have the faintest idea what it might be, which suggests that it is, as I said, utter tosh.

You presumably think there is no optimal top speed, and that everything just gets infinitely better as traffic moves infinitely faster? I think that's clearly barmy, and don't see why the onus isn't on you to explain your ideology of infinite speed and progress.

I have no such ideology, nor have I made any claims as to the existence of an optimal speed, nor any theories as to what it might be should such a thing exist.

You are the one plucking a figure out of the air, and the one with the need for a supporting argument.

Do you accept, for a start, Coruskate's point that faster-moving vehicles make greater demands on space?

Of course. A cross-channel ferry needs a lot more space to stop, and to turn, than does a pedestrian. But then a ferry carries a lot more people a lot further in a lot less time, so the fact in isolation tells us absolutely nothing about what any optimal speed might be.

 

[theclaud]

Nope. faster-moving vehicles only 'demand' greater space if maintaining a stopping distance is a priority of the operator. Riders on a group social ride don't increase the gap to the bike in front simply because the speed of the group increases. As demonstrated on every FNRttC I've been on.

In normal circumstances what would cause the vehicle in front of you to come to a dead stop such that you would require all your stopping distance to avoid hitting it? Vogon constructor ship materialising in its path? WMV pulling out from a side turning? Mr SMIDSY recognising that my Cinquecento contains a habitual passenger who would rather be cycling?

We weigh up the risk of things going wrong and we compensate accordingly. We don't demand more space; we evaluate the risk to our safety and act on the result (sometimes erroneously). We sacrifice safety for speed. Even on bikes.

How about a child running from behind a parked car?

Never mind the operator - when it comes to heavy objects moving fast, stopping distance is the concern of all of us. Ignoring for the moment the fact that there are many ways in which cars and bicycles are not the same - there is no motoring equivalent of the peloton - why, according to your theory, is the whole traffic jam on the motorway not whizzing along happily at 70mph? And why do we not hurtle past pedestrians at 25mph, millimetres from their elbows?

 

[theclaud]

I have no such ideology, nor have I made any claims as to the existence of an optimal speed, nor any theories as to what it might be should such a thing exist.

So you are leaving us guessing about what you think? That makes any constructive discussion hard work. Do you think that the notion of an optimal speed makes sense or not?

The figure is not plucked out of thin air - it is, as I said before, notionally "the speed of a bicycle". In other words it is the speed enabled by a simple, durable and equitable technology that extends human beings' natural animal capacity for mobility. You seem to have an aversion to illustrative quotations, so here's another, to explain how why the base reference for determining the optimal speed is its relationship to our natural mobility:

People solely dependent on their feet move on the spur of the moment, at three to four miles per hour, in any direction and to any place from which they are not legally or physically barred. An improvement on this native degree of mobility by new transport technology should be expected to safeguard these values and to add some new ones.

 

[GrumpyGregry]

How about a child running from behind a parked car?

One such death or maiming is too many. I am an advocate of compulsory 20mph speed limits, GPS enabled speed limiters, mandatory re-testing, I think we should use a system of colour tagged registration plates in place of 'tax' discs, have reg no camera's in every town, have cameras on every traffic light and speed camera's on every lamppost, we should fund compulsory insurance via a levy on fuel and stick 50p a litre duty on it too, etc., etc.. Driving/car use is a privilege not a right.

Never mind the operator - when it comes to heavy objects moving fast, stopping distance is the concern of all of us. Ignoring for the moment the fact that there are many ways in which cars and bicycles are not the same - there is no motoring equivalent of the peloton - why, according to your theory, is the whole traffic jam on the motorway not whizzing along happily at 70mph?

Clearly you don't drive on the M25 very often. Densely packed cars, each significantly less than the safe stopping distance behind the car in front, all hurtling along at 85mph. In relative safety. Everyone relying, as per a peleton, that no one else is going to do anything daft and bring it all to a crashing halt. I don't think it gets more equivalent than that. In these parts the M25 is known as the 90mph car park.

None of the reading I've done around queuing theory as it applies to motorways has persuaded me that speed, per se, is what causes traffic jams. Chokes, idiot operators, etc., etc., perhaps but not speed. ymmv and I'll read anything you direct me to that demonstrates otherwise.

And why do we not hurtle past pedestrians at 25mph, millimetres from their elbows?

Who we? Plenty of (RLJ'ing) people on bikes have passed me on foot (in London) going 'flat out'. One or two have had the ignominy of coming second in the ensuing collision with my shoulder. In fact I got a round of applause and several cheers from other peds when I offed a fakenger in November.

 

[theclaud]

Clearly you don't drive on the M25 very often. Densely packed cars, each significantly less than the safe stopping distance behind the car in front, all hurtling along at 85mph. In relative safety. Everyone relying, as per a peleton, that no one else is going to do anything daft and bring it all to a crashing halt. I don't think it gets more equivalent than that. In these parts the M25 is known as the 90mph car park.

None of the reading I've done around queuing theory as it applies to motorways has persuaded me that speed, per se, is what causes traffic jams. Chokes, idiot operators, etc., etc., perhaps but not speed. ymmv and I'll read anything you direct me to that demonstrates otherwise.

Who we? Plenty of (RLJ'ing) people on bikes have passed me on foot (in London) going 'flat out'. One or two have had the ignominy of coming second in the ensuing collision with my shoulder. In fact I got a round of applause and several cheers from other peds when I offed a fakenger in November.

I'm not sure why we're at odds - I'm not arguing that speed causes traffic jams - I'm arguing that speed, and the everyday requirement to travel at higher speeds, degrades the social environment. The very existence of the M25 does exactly that, whatever speed the vehicles on it happen to be moving at a given time. The 20mph speed limit you favour is just a slightly higher estimate of where the threshold lies - I would contend that it is probably lower, and that the 20mph figure is a nod to the needs of motorists (it's the lowest speed limit they are currently prepared to countenance). The peloton is voluntary and co-operative - motorists do not pack together densely by choice, and there is no advantage in doing so. There is no environment more hostile to pedestrians and cyclists than the one you describe - fast moving AND densely packed. And no, I never travel on the M25 if I can help it, although there was a time when I frequently did.

 

[BentMikey]

Oh, of course the fast cars on the motorway don't take more space because of their speed. Just look at this image:

http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=51.453004,-0.521534&spn=0.002561,0.004061&t=k&z=18

 

[CopperBrompton]

So you are leaving us guessing about what you think? That makes any constructive discussion hard work. Do you think that the notion of an optimal speed makes sense or not?

No, the notion of some kind of universal optimum speed is obvious nonsense. The optimum speed for an airliner flying to Hong Kong will be very different to the optimum speed for a car on an empty autobahn which will in turn be very different to the optimum speed for a pedestrian walking down the escalator at Oxford Circus.

The figure is not plucked out of thin air - it is, as I said before, notionally "the speed of a bicycle". In other words it is the speed enabled by a simple, durable and equitable technology that extends human beings' natural animal capacity for mobility.

Your contention, which you're working very hard to distract attention from, was that is is not possible for one person to exceed 15mph without slowing down someone else. I am asking you to support that contention with either evidence or at least a plausible argument. So far you have done neither, but merely shifted ground.

People solely dependent on their feet move on the spur of the moment, at three to four miles per hour, in any direction and to any place from which they are not legally or physically barred. An improvement on this native degree of mobility by new transport technology should be expected to safeguard these values and to add some new ones.

In which case you are arguing that cyclists should never exceed about 3mph when alongside a pavement so that pedestrians are free to move across the road at will. It's a defendable point of view, but not one which is likely to see a great deal of support.

 

[theclaud]

No, the notion of some kind of universal optimum speed is obvious nonsense. The optimum speed for an airliner flying to Hong Kong will be very different to the optimum speed for a car on an empty autobahn which will in turn be very different to the optimum speed for a pedestrian walking down the escalator at Oxford Circus.

Your contention, which you're working very hard to distract attention from, was that is is not possible for one person to exceed 15mph without slowing down someone else. I am asking you to support that contention with either evidence or at least a plausible argument. So far you have done neither, but merely shifted ground.

In which case you are arguing that cyclists should never exceed about 3mph when alongside a pavement so that pedestrians are free to move across the road at will. It's a defendable point of view, but not one which is likely to see a great deal of support.

That's a relief! I thought you were being deliberately obtuse, but now I see that you are merely missing the point entirely. I'm not remotely interested in the optimum speed for airliners and autobahns. I'm talking about a socially optimal traffic speed, not a speed that suits an industry or a class of passengers.

You're having trouble with the contention that one person's high-speed transit slows another down. How about a simple example. Person 1 wishes to travel on foot from A to B. Between A and B is a road on which Person 2 is travelling, let's say at 30mph, by car. Person 1 will either have to stop and let Person 2 pass before crossing, persuade Person 2 to stop or slow down, operate elaborate equipment to force Person 2 to stop or slow down, or die. This is because Person 1 and Person 2 are not equal. It doesn't stop there, of course. Person 1 is on the way to work. Because it is expected in his culture that people will drive to work, his workplace has been relocated to an industrial estate not served by public transport. It now takes him an additional hour to walk there. He could buy a car, of course, but he'd have to work more to earn the money to buy the car... etc. etc.

 

[CopperBrompton]

I'm not remotely interested in the optimum speed for airliners and autobahns. I'm talking about a socially optimal traffic speed

For what? Where? In what circumstances?

Your earlier messages suggested that it was a universal limit, now we know it doesn't include planes or autobahns. Does it include dual-carriageways? Roads that currently have a 50mph limit? Roads that currently have a 40mph limit? Do you really mean that pedestrians should be able to step out into a road at will in front of trucks, cars and cyclists and that the latter must all be doing a speed that makes this feasible?

Person 1 wishes to travel on foot from A to B. Between A and B is a road on which Person 2 is travelling, let's say at 30mph, by car. Person 1 will either have to stop and let Person 2 pass before crossing, persuade Person 2 to stop or slow down, operate elaborate equipment to force Person 2 to stop or slow down

The highly elaborate equipment of some black and white paint, a couple of poles and some orange plastic spheres seems to work pretty well.

Person 1 is on the way to work. Because it is expected in his culture that people will drive to work, his workplace has been relocated to an industrial estate not served by public transport. It now takes him an additional hour to walk there. He could buy a car, of course, but he'd have to work more to earn the money to buy the car... etc. etc.

As a matter of mild curiosity, where is this industrial estate that isn't served by public transport? As far as I'm aware, it is a condition of planning consent for any industrial estate that public transport provision has been made.

 

[Twenty Inch]

Mikey I've just looked at your sig link - the Royal Charles was taken a bout a mile away from where I live. Come down to Medway one day, at 16mph, we'll go around Upnor Castle together.

 

[CopperBrompton]

Come down to Medway one day, at 16mph, we'll go around Upnor Castle together.

This is just the kind of selfish, irresponsible behaviour Claudine is trying to prevent. Kindly limit yourselves to the optimum speed of 15mph.

 

[Dan B]

The highly elaborate equipment of some black and white paint, a couple of poles and some orange plastic spheres seems to work pretty well.

Not on Bethnal Green Road it doesn't.

 

[CopperBrompton]

I wonder what's changed since I lived there. They always worked just fine for me (the occasional Richard Head excepted, of course).

 

[BentMikey]

Mikey I've just looked at your sig link - the Royal Charles was taken a bout a mile away from where I live. Come down to Medway one day, at 16mph, we'll go around Upnor Castle together.

I'd love to one day. I'm a distant descendant.

 

[BentMikey]

I wonder what's changed since I lived there. They always worked just fine for me (the occasional Richard Head excepted, of course).

I suspect that:

There often aren't pedestrian crossings at many of the places where people want to cross.
You've become significantly polarised in the debate, so much so that you can't admit a single good point made by theclaud.