Safety In Numbers

'Safety in Numbers' is the theory that there is a correlation between cycling levels in an area, or country, and the relative safety of cycling - that higher cycling levels correlate with higher safety levels. 

A strong form of this theory is that simply increasing cycling levels will increase (relative) safety. Weaker forms simply point out the correlation, without making any strong causal connections.

It is more likely, for instance, that safer environments lead to higher cycling levels, or that higher level policy creates attractive and safe conditions that boost both the numbers of people and their relative safety. Fred Wegman of the Dutch Institute for Road Safety Research

 If there is much cycling in a country, the risk for cyclists is indeed lower. Comparison of statistics of different countries offers conclusive evidence. The risks in countries that have a lot of cycling like the Netherlands and Denmark are (much) lower than in countries where cycling is a less important mode of transport. The explanation may be twofold. Firstly, there are the expectations of the other road user. If a driver does indeed expect a cyclist on the road, as is the case in the Netherlands and Denmark, the risk is lower. But a second explanation is conceivable: if there are more cyclists, more safe cycling facilities will be constructed (which in turn make cycling more pleasant). We have sufficient evidence that cycling facilities (like bicycle tracks) reduce the risks of cycling. Not only do the Nether- lands and Denmark have many cyclists, there are also many cycling facilities.

I do not expect that just a greater number of cyclists will on its own result in a risk reduction for the cyclist. On the other hand, I do expect that more cycling facilities will lead to lower risks. Policy that only focuses on an increase in cycling and at the same time ignores the construction of more cycling facilities, will not have a positive effect on road safety. Unless, of course this policy also takes care of cyclists only cycling close to one another: in a swarm, school, flock, or pack of cyclists.