Gyratory traffic schemes, extended one - way systems etc

That's better. A proper argument :-)
However if, as we are, you were discussing a scheme which was specifically about buses sharing a road with cycles and you asked the same questions you would get a higher number of people singling out buses rather than vehicles in general.

Well, if there was no question about other vehicles on that street (although in all likelihood there'd be taxis, too), of course people would mostly talk about buses. That's irrelevant to the general point, though, which was the main thing we were talking about. The simple fact is that buses do not constitute a big problem for cyclists. Again, I'm happy to be corrected on that with proper evidence, but I've studied what there is and there are (a) few collisions between cyclists and buses, (b) bus driver training has improved greatly over the last few years, and (c) complaints about buses are low. Show me otherwise and I'll agree with you.

I expect bus speeds on such a road would be a lot higher for example, so it's likely that the perception of danger would increase substantially.

No, bus speeds wouldn't be higher. Plus, as what counts for perception of danger in Central London are burst speeds, and there wouldn't be issues with buses being stuck in congestion on a bus, cycle, and taxi-only street, there would not be speed bursts. I strongly suspect that Camden would want to make the street 20mph. I'm just speculating in all this, of course, as I haven't seen any proper information on the plans.

I linked to the article, by the way, because it was a decent argument in favour of the proposition that the perception of cycling safety is enhanced when there aren't buses (or any other heavy traffic), to which "simply nonsense" was not an adequate riposte.

I never objected to that claim (although there are a number of things with which I disagree in that post). My claim is simply that it's nonsense to claim that 'there is nothing like having to share space with buses for reducing the feeling of subjective safety for cyclists'. Here's what I wrote:

I certainly disagree with the claim that 'there is nothing like having to share space with buses for reducing the feeling of subjective safety for cyclists'. This is simply nonsense.

Danger from buses is an issue, but not by any stretch of the imagination the biggest issue. Note also that I specifically distinguished between buses and other heavy vehicles. There is a big difference between those two classes of vehicle and the ways in which they are used.

This is a sound argument, but it's an answer to a different question.

Yes, that's why I added the other paragraph. I should have included it all in one post, as it's necessary background.

Dividing the number of collisions by passenger trips is irrelevant to the two questions that matter when you need to find out about cyclist's perception of danger. These questions are "as a cyclist are you more likely to be hit by a bus or a motorcycle" and "if you are hit by a bus, are you more or less likely to be killed or seriously injured than if you are hit by a motorcycle". I believe that the answer to both these questions points to the bus as the bigger perceived (and actual) risk.

It's not irrelevant because it's useful to enable people to understand their perceptions better. People often don't understand quite how much the bundling of trips in one bus reduces potential road danger. Also, most people wouldn't be able to give you an answer to either question, because they simply wouldn't know. To investigate perception of danger, you'd have to ask completely different questions, e.g. 'what are you more afraid of, buses or motorcycles?' or 'are you more afraid of the consequences of a collision with a bus or with a motorcycle?' Perception of danger generally isn't informed enough to say much beyond something about a state of fear. You may have decided views on that, but, again, you would find that most people hadn't thought about this much. What you will find when you talk to people is that they are just afraid of 'traffic', without making much of a distinction between modes. And, once more, buses are rarely cited as the number one, or even a prominent cause of danger.