[OSM-talk] Tagging for street danger levels

[Toby Murray]

On Sun, Jun 20, 2010 at 7:34 AM, Richard Mann
<richard.mann.westoxford at googlemail.com> wrote:
> There's a school of thought that would like to see cycle maps produced
> in this way (the people in Cheltenham call it the Cheltenham
> standard), using a 5-point scale (roughly: dead-quiet, ok if you can
> manage a straight line, need to be able to deal with a few cars, need
> to be able to look over your shoulder, need to be able to go as fast
> as the cars at junctions). Some of these are tagged as
> cyclability=1|2|3|4|5, but I don't know anywhere that's done it on a
> comprehensive basis using OSM. You could probably derive the values
> from the traffic volume and the typical speed, if you want to do it
> scientifically.

Looking at tagstat, it is indeed pretty rare. There are a total of 18
ways tagged with the cyclability tag. But I do like this idea. I don't
really like relying on speed and type of road (primary, secondary,
etc) for extrapolating cyclability. It is a good start but there is
more that contributes to the overall cyclability of a given road. A
lot of it has to do with visibility and sometimes vertical climb. I
feel much more comfortable riding on busy streets if I can keep a 20+
mph pace as opposed to climbing a hill at 10.

> In Oxford, we tend to focus on levels 2 & 4 in that hierarchy, and
> look for how you can get about the city if your skill level has
> reached those two points. From that we've identified two networks for
> getting about (the "main" and "quiet" networks). We've used
> mcn=something for the main routes and lcn/lcn2=something for the quiet
> routes.

This is certainly a good idea for producing the "routes you DO want to
take" map. I will have to look at some of the data in Oxford and see
how to adapt it here.

> As for rendering, you can either try to persuade Andy (the guy behing
> opencyclemap) that he wants to include it (or probably better) render
> it yourself. I've been getting quite a long way with Maperitive (which
> is a fairly simple but not quite fully developed renderer for the
> non-geek). Halcyon may also be available before too long.
>
> You can see what we've done at
> http://www.cyclox.org/oxford-journey-planner/cyclox-map/

Yeah, we are looking into doing some of our own rendering but if we
can indeed come up with a workable standard I think it would be great
to get other renderers to pick it up as well.

Toby