[OSM-talk] Highway tags and other junk

[Dominic Hargreaves]

On Thu, Dec 14, 2006 at 07:04:45AM +0000, Tom Chance wrote:
> Ahoy,
> 
> On Thursday 14 December 2006 03:22, Ben Robbins wrote:
> > Before you  say these don’t need to be labeled separately please note that
> > the average speed on the 1st type would be about 55mph, while on the 4th it
> > would be about 15mph.  A route planner must sort these apart.
> 
> That can be covered with the speed limit tag.

Surely it's obvious that this isn't true? The speed limit on all four
types of road could quite easily be 60mph (national speed limit) in the
UK.

Another tag: expected_speed or similar, maybe. But please don't start
polluting what is intended as a record of the legal speed limit with
practical and safe limits.

In any case I think we can't hope to maintain accurate information about
expected speeds as an additional tag; it's information that could indeed
be inferred from the categories Ben describes.

> > 1)  Make an additional value, which has 4 possible tags in which you enter
> > 1 of them.  These are predefined by how they appear in the field.
> > 2)  Have 4 tags to go under highway.
> 
> I think the best way to go would be to clearly separate the official 
> classification (probably unclassified in these cases) from the physical 
> features (width, surface condition, etc.) and features relevant for 
> particular contexts (speed limit, safety for cyclists, pavement, etc.)
> 
> If we made this distinction then it would suddenly make it easy for you to 
> have a really good schema for different gradations of track, as you have 
> developed on the wiki. I suppose that with the current schema it seems a bit 
> overkill for most people's needs, so ends up existing in parallel with the 
> more blunt "highway=track" tag.

+1 to all that.

The problem is making it easy for people to tag roads with correct
information, and for this we need the XML-based Map Features, and
editors that have knowledge of this.

Cheers,

Dominic.

-- 
Dominic Hargreaves | http://www.larted.org.uk/~dom/
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