[OSM-dev] Relationships - working prototype

[spaetz]

On Thu, Aug 16, 2007 at 10:46:57AM +0100, David Earl wrote:
> On 14/08/2007 00:16, Frederik Ramm wrote:

> I think this prototype will solve a huge swath of the problems with 
> routes, disjoint streets, turn restrictions and so on.
> 
> I thoroughly commend it. The sooner it is implemented the sooner many of 
> the hacks currently being proposed will go away.

I agree that it will solve many problems that are currently deemed unsolvable. oof course can turn restriction be modeled in the way Steve proposed and that might actually be the easier solution when it comes to turn restrictions. But this simple data model comes at the price of much manual labour. Ever tried to rename or reclassify a stretch of road with many bridges and tunnels (or where the road is split for other reasons)?

Having such a relationship model introduces some more complexity, but then it will simplify much of what is currently hard/impossible. Misspelled the state of Misssisipi? rather than finding and fixing all is_in=missisipi,us and is_in:us= and is_in_us_state=... you look up the is_in relationship once and change that. It complicates things (which can and should be abstracted away by editors!!) but simplifies them too.
Steve's preferred model keeps things simple but requires many monkeys fixing thousands of tags. Given that my monkey time is limited, I'd rather choose a drop down box in JOSM, stating: rename "Parke Avenue" to "Park Avenue" once, which would find all bits and pieces, be they o bridges or not.

> I'm surprised there hasn't been much response on the list at all, let 
> alone excitement about it. The fact that you've done the donkey work of 
> incorporating it in JOSM and the API means it has a good chance of 
> success; and I particularly like the fact it will not break existing 
> data consumers (unless they object to an XML element type they do not 
> understand) yet osmarender will find it easy to consume the new data i 
> due course, to label routes and so on.

I like the model. But I would never expect users to have to enter those relationships manually as is done now with tags. Having a nice drop down box to choose from would be a good step, I'd say.

> grouping ways, then if a generic term is wanted "group" might be better, 
> or to make it less generic, "waygroup" or "way-group".

But that would be not so appropriate for e.g. turn restrictions, wouldn't it? I like "relations" personally, but then I don't care how they are called actually.

spaetz> 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 186 bytes
Desc: not available
URL: <http://lists.openstreetmap.org/pipermail/dev/attachments/20070816/ab207492/attachment.pgp>