How to map the National Byway loops?

General talk
1

Having just been round the Easingwold Loop of the National Byway I was wondering how best to tag it. The Wiki (http://wiki.openstreetmap.org/wiki/National_Byway) says to create a relation for the loop but I have a number of questions.

The Byway passes eastwards through Easingwold and one side of the loop, so to speak, consists of the Byway itself and the loop forks off northwards from the Byway (at Brandsby) and then, er, loops back via Ampleforth to Easingwold. The Byway itself continues eastwards.

The Byway itself should be tagged with the relation 9327 which has already been set up. I’m happy with that bit although I haven’t done it yet.
I need to create a relation for the Easingwold Loop. I’m happy with that bit too, although I haven’t actually done it yet either.

Should I tag the complete loop with the new relation (so that the Easingwold Loop and the Byway run along the same Way) or should I just tag the loop back?

The loop is directional and only signposted 1 way round (anti clockwise in this instance). I couldn’t follow the loop round the “wrong way”. How can this be indicated?

Thanks,
Steve

2

Interesting question. I think the NB loops on which I’ve done some work in the past (the Oakham Loop and the Bernwood Forest Loop) have been only tagged on the bits that diverge from the main Byway. But I can see the logic in tagging a complete circuit.

For the loop direction, you could add “direction=anti-clockwise”. It might also be possible to add the relation members one-by-one, in order, in the anti-clockwise direction, and then add “oneway=yes” to the relation. But relation ordering is not widely supported as yet - Potlatch doesn’t take any notice of it, for example.

3

For the loop direction, add the ways to the relation as “forward” or “backward” members. It doesn’t matter what order the ways are added to the relation. Note the forward/backward is relative to the direction of the way, not the direction of the relation.
See http://wiki.openstreetmap.org/wiki/Relation:route#Members

4

Thanks Vclaw, but I don’t understand relations well enough to know how to do this. How do I indicate it using Potlatch?

Cheers,
Steve

5

You can see how a forward/backward (cycle) route looks on the cyclemap layer for NCN1 through Colchester here:
http://www.openstreetmap.org/?lat=51.88888&lon=0.89395&zoom=17&layers=00B0FTF

This image shows one of those ways selected in Potlatch:

You will note the arrow in the bottom left is pointing upwards, indicating the direction that the way is drawn. Then in the box next to the relation (ncn 1) you can type forward or backward (in this example forward) to indicate that the route goes along the way in the same direction as it was drawn.

I hope this helps.

6

It does, thank you.