BBC article on cycling accidents

Clustering around what, though? The PD needs some dimension, such as time or distance, for observations to cluster in. But in this case we're not interested in time, or distance, or even sequence. We're interested in how many people died, from these populations, this year. And, sadly, this year's numbers aren't much different from last year's numbers.

Statistical significance does improve with a larger sample size, but as I keep saying, we have a large sample size which is all male and female cyclists this year. Not the 8 that we observed to die.

Your point about extrapolation and clustering would apply if, for example, out of the 50 or so cyclists that ride down the side road next to my flat each year, three of them had been killed by an HGV. 50 people is a small sample. Out of all of the people who had been killed by an HGV in London, one might expect to find some geographical clusters. That being so, you wouldn't want to extrapolate from the three deaths per 50 to a similar proportion of deaths in the wider cyclist population. But that's emphatically not what is going on here. The sample size is large to begin with.

Either way isn't clustering or not rather missing the point? Any death on the road, cyclist or other wise, is a terrible event. but why are roads more dangerous than trains or planes for example? because any major incident of mass transit invloves a "cluster" and so a large amount of time and public money will be invested into ensuring it doesn't happen again. (I can't find it now but there was an Economist article a few years ago about how much more money was being spent on per life saved on the railways by introducing ATP compared with how many more lives could be saved on the roads for the same budget by improving bad junctions etc) Be it true or not if you can create a public perception of a lorry incident cluster won't it drive a action to work on the problem? Shit as it is, it's an arguement about politics as much as fact.

Yes, if we're talking about cycling deaths in general. I'm not, though. I'm talking about lazy assumptions (neither of yours) about female behaviour extrapolated from one statistic, which has a thankfully tiny sample size, which is the number of females killed in London compared to cyclists as a whole killed in London in that year.