Viewing a single comment thread. View all comments

coldsnap123 t1_iv2pta1 wrote

Reply to comment by Nabs617 in Brattle Street bike lanes are being installed next week. by greemp

How safe is safe enough?

−16

vhalros t1_iv3l3ov wrote

A reasonable question; I can think of a few different ways to answer it.

We could look at other places with safe cycling infrastructure, and compare to their statistics (the Netherlands has around 1.4 killed per 100 million kilometers cycled, for example).

We could also answer it with surveys on the perception of safety. This has some downsides, because it is subjective. But the subjective feeling of safety is also important, because facilities that do not feel safe will not be used.

We could also look at the deaths and injuries that do occur, and consider if they are really bizarre black swan events (person on bicycle eaten by escaped zoo lion), or things we actually do know how to prevent/greatly reduce, like doorings, right hooks, etc.

Right now, we often see people die from events we know could be mitigated by better infrastructure, and that such things could be practically deployed.

16

st0j3 t1_iv2tni3 wrote

I think the general movement suffers from some flaws:

  • Risk / safety are often assessed based on perception rather than evidence. Groups complain that they don't feel safe biking, and so push for action.
  • Many bike advocates seem to believe zero risk / perfect safety is achievable, but it's not. Because they don't understand zero risk is an aspiration goal that isn't possible to actually achieve, I think there is no point at which they will be satisfied.
  • There is a diminishing return on safety and increasing costs for each improvement. Bike advocates seem to not acknowledge the various types of inconveniences and other costs any (perceived) increase in safety they push for requires.

Don't get me wrong: There are good ideas that should be implemented. But there are also some really shit ideas that shouldn't be implemented under any conditions, as well as a point where biking is "safe enough".

−12

dny6 t1_iv5yiwl wrote

Perceived safety is crucial for actual use of the infrastructure though.

The city of Cambridge has done actual research on this — and it is clear that the majority of people who want to bike won’t until bike lanes are physically separated from cars.

Without perceived safety — you end up with empty bike lanes, leading to the never ending tit for tat that no one bikes, which just isn’t true

8

crazicus t1_ivyc7xu wrote

Why is perception of safety not a good metric? If a system is perceived to be unsafe, people won’t use it.

1