What's your top speed?

@Oliver:

I agree with most of what you've said (I used to work for a company that did transport data applications and worked quite closely with TfL so I know the arguments in favour quite well).

There is no question that articulated buses have some drawbacks, just like other kinds of buses have other drawbacks. The key is to put them into perspective against those benefits.

However, the design of bendy bus used in London was really intended for continental (particularly German) cities with large ring roads with a dedicated uninterrupted bike (EDIT: "bus", not bike sorry) lane.[/qupte]

Actually, you'll find that one of the main reasons why this impression arises is that in most German cities the centre with narrow streets is pedestrianised. It's one of London's peculiarities that there is a bizarre expectation that motor vehicles should be permitted to be driven along streets that would be pedestrianised on the Continent. (NB this is not all good, as pedestrianised centres are typically surrounded by a plethora of multi-storey car parks that create the illusion of car-freeness.) This means that bus operation is heavily constrained by other motor vehicle use in areas like the junction you cite below:

[quote]Anyone who has ever watched one trying and failing to make the turn out of Gower St, for instance, and blocking the traffic for several phases of the lights knows that TfL have been over-ambitious in the routes they've given the bendy buses.

Take away the excessive numbers of taxis and private cars in this area and articulated bus operation is absolutely not a problem, as these streets' dimensions are not actually all that constrained (but appear that way because there's always so much going on in a typical London street). You need to measure it (and the comparison with post-WW2 streets and ring roads) against vehicle capacity. Unlike most Continental cities, London has always been extremely congested--there are reports to that effect going back to Roman times! Just because Continental streets and roads are vastly over-dimensioned for the capacity required, they are not inherently more suited to articulated bus operation. All traffic flows faster and more freely there quite generally than in London. So, the test you need to apply is how you want London's limited capacity used--by public service/carriage vehicles or by private traffic. (NB obviously I think that there is a much bigger role to play for cycling to be part of the modal mix rather than public transport or private cars--the current Mayor of London has committed to a cycling target in excess of 5%, and there are hopes to go as high as 10% as in Berlin, for instance.)

Problem is that with the Tube PPP having been such a failure, buses are the only area of public transport that has been able to expand its passenger capacity significantly in the past decade, so we're probably stuck with an ever-increasing number of them.

Well, yes and no, as this is only the case with a combination of central London continuing to possess the lion's share of trip-generating potential, and a potential failure of Crossrail (if it doesn't fail, bus expansion will probably decline--I know that that's potentially a long time hence). However, it is widely recognised that Outer London centres need to be better developed, and although that message is always a bit difficult to get through to politicians, if we manage to further reduce the need to travel, again the kind of trip assistance with 'remote destination fulfilment', for want of a better word, that public transport delivers, may be reduced in importance, and walking and cycling come more to the fore. Hard to predict where it's all heading in the recession! There may well be a break in the continuity that we've come to expect over the last ten years.