[OSM-talk] Names, split streets and relations

Dave Stubbs osm.list at randomjunk.co.uk
Mon Jul 28 17:22:56 BST 2008

On Mon, Jul 28, 2008 at 3:50 PM, Karl Newman <siliconfiend at gmail.com> wrote:
> On Mon, Jul 28, 2008 at 2:32 AM, Dave Stubbs <osm.list at randomjunk.co.uk>
> wrote:
>> On Mon, Jul 28, 2008 at 6:23 AM, Karl Newman <siliconfiend at gmail.com>
>> wrote:
>> > On Mon, Jul 28, 2008 at 12:55 AM, Gervase Markham <gerv-gmane at gerv.net>
>> > wrote:
>> >>
>> >> Karl Newman wrote:
>> >> > I think the "obvious" thing is to quit splitting ways just because
>> >> > there's a bridge or the speed limit changed... IMHO, the only reason
>> >> > to
>> >> > split ways is if the name changes or if the major type changes.
>> >>
>> >> Er, correct me if I'm wrong, but it's not possible to apply a tag to
>> >> only part of a way. So if the speed limit or anything else changes, you
>> >> can't have a continuous way if you want to tag correctly.
>> >>
>> >> Gerv
>> >
>> > I was thinking about this (not my proposal, but I like the idea):
>> > http://wiki.openstreetmap.org/index.php/Relations/Proposed/Segmented_Tag
>> >
>> Personally I classify that as more complicated, more surprise, and
>> with the added danger of hiding information. It might work with very
>> good editor support, but given how long we had segments, and how the
>> interface for figuring out them was never really fixed, my hopes
>> wouldn't be too high. I think fixing the renderers for this is much
>> more preferable (rather than fixing the renderers to cope with these
>> fake segments.. which doesn't sound too fun actually).
>> Dave
> It's not just a rendering issue, although that's the topic of discussion. It
> makes it much easier for editing and later processing (it's easy to split a
> way, not as easy to recombine it). Currently, if you want to add or modify a
> tag on a long way, you have to click on each section to change the tag. In
> the degenerate case, you'd click on every single segment. I realize it would
> require good editor support, but it's disheartening to see the "we've always
> done it that way; why should we change?" crowd coming out already on a
> project this young.


The editing issue is actually the one I was primarily talking about.
Forget the rendering, it's swings and roundabouts, and it'll work
either way.
Now as I've said before, I think the whole editing tags on a split way
"problem" is hugely inflated. It's usually very obvious what's
happening, and in JOSM you get to select all the parts and edit the
tag just once if you really want. There's a good usecase here for
improving the editors -- some sort of "also select same named objects
please" key (hey, it probably exists already...).

The real problem (which we had with segments, and are now getting
again with relations) is hidden information. Abstract relationships
between objects that aren't visualised cause people to add duplicates
and break existing stuff without even realising it. Some of this comes
down to overlapping feature support, which TBH is pretty terrible atm,
has been forever, and is genuinely difficult for a UI to cope with.
The segmented way relation works fine logically, has some distinct
advantages, but it needs really good editor support, otherwise it'll
just generate a big mess.

So not because "we've always done it that way", but because we used to
do it a different way and it sucked.


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