[OSM-talk] tagging and rendering highways in the USA and elsewhere

[Peter Miller]

Thanks for that Jeffrey. I agree entirely that rendering should follow
tagging and not lead tagging, my main concern at the moment is that UK
rendering (blue for motorway and orange for secondary) is encouraging
inappropriate tagging. I think we agree that one should clarify first how to
tag what is on the ground and then decide on how to render the data. Based
in the UK I am reliant on tiger and aerial photography to inform my choice
of tagging Am I right in thinking that the synthesis of this discussion is
being added to this wiki page?

http://wiki.openstreetmap.org/index.php/Highway_tag_usage

 

Fyi I have been doing a lot of work on the San Francisco bay area (Golden
Gate down to Foster City) over the past week or so and I am having been
working on the road classes tags today, hence my question. I have been:

 

Lifting the road class of roads tagged as secondary but which have flyovers
and divided carriageways etc and making them trunk (but motorway might be
more appropriate)

 

Lifting 'braded roads' with two carriageways in tiger data from residential
to primary.

 

Lifting some other roads from residential to secondary where they are
clearly significant feeder roads for an area.

 

Rationalising link roads to get them to match the class of road they are
feeding (there were lots of motorway_link roads feeding secondary for
example).

 

My first pass looked pretty ugly. I am currently waiting for osmarender to
render my latest adjustment to the primary network in the area and would
then be grateful for feedback as to whether I am on the right lines (but do
wait until tomorrow when the rendering should have finished).

 

I have also being doing a lot of 'de-duplicating' of roads pre/post tiger.
In general I have kept pre-tiger freeways and kept tiger for other roads. I
have also given a pass over most of the freeway network in the bay area in
the past week and have added the second carriageways where required and
cleaned up the geometry and sorted out some of the junctions.

 

 

 

 

Regards,

 

 

 

 

Peter

 

 

 

  _____  

From: Jeffrey Martin [mailto:dogshed at gmail.com] 
Sent: 20 April 2008 15:42
To: Peter Miller
Cc: Talk Openstreetmap; talk-us at openstreetmap.org
Subject: Re: [OSM-talk] tagging and rendering highways in the USA and
elsewhere

 

 

On Sat, Apr 19, 2008 at 1:15 AM, Peter Miller <peter.miller at itoworld.com>
wrote:

 

Major non-interstate highways that have traffic light free multi-level
junctions etc should be tagged as 'trunk' and possibly also be rendered
orange but with less grand route numbers to differentiate them from
interstate routes.

This statement really bothers me. First, we must make every effort to keep
the data separate
from the rendering.

Consider a section of Interstate Highway that structurally resembles a UK
motorway. This section of road may also be part of a state highway. It's not
uncommon for a section of
road to have both a state highway sign and an Interstate sign. In some very
barren
areas an Interstate may have standard intersections without ramps. As in
your example above a road that is not an Interstate may have multiple levels
and ramps.

Whatever scheme we agree on must keep the road's structure separate from
legal classifications. I checked and the wiki still says that the highway
tag should be
used to indicate what the road looks like. My reasoning can be found on the
talk page.

Whether a road is an Interstate, state highway, county road, etc. should be
indicated in another data field.

I haven't been following all the conversations lately, but I remember an
Australian
was tagging a gravel road as a motorway because it was the main road between
two rural cities and he wanted it prominently rendered. Perhaps in this case
some
kind of importance tag should be used.

I think free tagging is great, but we should not allow multiple definitions
for each tag.
A tag should not indicate both it's legal status and it's structure,
although one might
imply the other under certain circumstances.

-- 
http://bowlad.com 

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