[talk-au] [OpenStreetMap] Re: Mapping intersections in OSM

Ross Scanlon info at 4x4falcon.com
Tue Nov 29 11:20:14 GMT 2011


On 29/11/11 09:59, Supt_of_Printing wrote:
> Maybe I'm missing something or don't have a full understanding
 > of the OSM applications.
 > By the way, I am not trying to be difficult, and certainly not
 > "payback" as Nick seems to suggest, just simply wanting
 > to get an accurate reflection of features and have it looking
 > as professional as possible. So please let me know if I'm
 > missing something.

To me what renders in the area you modified the intersections is not 
professional and, no offence intended, when shown to a non osm 
contributor they described it as childish.  This person worked in 
mapping sections of the AU military.  The intersection I used as an 
example is not an accurate reflection of the feature on the ground.

> If the map rendering after editing is accurate, simple, not having an
 > over-abundance of directional arrows filling an intersection, or an
 > over-abundance of street names on every little bit of slip lanes and
 > approach lanes, etc., what does it matter what the edit mode is like
 > as this is not the mode people look at to find out information, but
 > rather the finished product.


I agree with what you are saying about names on slip roads, direction 
arrows, etc but this is not a data issue.

All these things need to be included in the data as it is used for more 
than just creating maps.  This information is used for other applications.


What is needed to resolve your issues is corrections to the rendering.

For example a rule for the render needs to be,

"At a dual carriageway intersection where the section of way across the 
intersection from one section of carriageway tagged as oneway to another 
tagged as oneway and the length of the way is less than 100m then do not 
render a direction arrow and the name."

This would appear to be a continuation of the oneway carriage ways 
either side of the intersection without arrows or names in the 
intersection.  However how to convert this into something that the 
renderers can use is rather complicated at the moment.  It is something 
that I have investigated and have been unable to get mapnik to do it, 
I'm still working on it however.


However for a router, the direction and name information is still 
available and you would end up with,

"At the next intersection continue straight ahead on primary road A"

If the direction and name information was not there then the router 
would come up with something like,

"At the next intersection continue straight ahead from primary one way 
road A, to the primary two way road, then straight ahead on primary one 
way road A"

where A is the name of the roads.

It's not easy for a router to determine direction by the ways without 
the information on the way.  So the way needs to be drawn in the correct 
direction for a one way road and then tagged to indicate oneway=yes.  To 
show that you can not enter it from the wrong end.

These items have been discussed from the very beginning of osm and I'm 
sure they will come up again.  Given that the people who work on them 
are all volunteers then it takes time for things to get done.

It would be nice to see bing release their renderer to the open 
community as it looks good but for the intersection I gave in the 
example even their data is wrong.

The main thing with osm is the accuracy of the data, the professionalism 
of the finished product(s) is the realm of the renderers/routers.

Cheers
Ross


> SoP
>
> On 2011-11-28 16:28:37 UTC Rosscoe wrote:
>
> > --e89a8f503964a7bd1204b2cdfe5b
> > Content-Type: text/plain; charset=ISO-8859-1
> >
> > Just a comment, there are many ways to render and to use the map so to me
> > the finished product is not the web rendering from Mapnik.  It doesn't even
> > show paved hard shoulders locally for cyclists.
> >
> > Rendering locally Maperitive does a nice job and you can configure what is
> > rendered and how it is rendered.
> >
> > Routing programs use the directional arrows to see if the junction can be
> > navigated.
> >
> > I think step one is get the information in the map, step two is rendering.
> >
> > Cheerio John
> >
> >>
> >
> > Hi Rosscoe,
> >
> > Supt_of_Printing has sent you a message through OpenStreetMap with the
> > subject intersections:
> >
> > ==
> > Well if someone can explain to me what is actually wrong with smoothing out
> > the chunky jagged curves on intersections, the useless street names on slip
> > lanes, etc., the useless over-abundance of directional arrows for every
> > little bit of the intersection where the direction is quite obvious (making
> > the intersection look messy), crossovers in median strips matching the
> > intersecting roads rather than the road it is actually in, etc., etc.,
> > etc., I may get it! But surely the aim is to give a professional and clear
> > non-confusing look to the roads on the finished product rather than how it
> > looks on the potlatch editing mode. I would rather the editing mode looks
> > like a bit of a dog's breakfast so that the finished product doesn't!
> >
> > And yes, I have read the thread on intersections. Perhaps someone can point
> > me to the rules that says"there should only be two through carriage
> > ways in both directions and the slip ways at the sides" as this
> > doesn't reflect reality, as there is not two through carriage ways with a
> > big square"island" in the centre of the intersection on the
> > ground.
> >
> > I will continue to edit to get the roads and intersections to look
> > professional, reflecting reality, rather than the confusing, chunky
> > rendering with an over-abundance of arrows and street names that I so often
> > come across.
> >
> > Supt_of_Printing
> >
> > --e89a8f503964a7bd1204b2cdfe5b
> > Content-Type: text/html; charset=ISO-8859-1
> > Content-Transfer-Encoding: quoted-printable
> >
> > Just a comment, there are many ways to render and to use the map so to me t=
> > he finished product is not the web rendering from Mapnik.=A0 It doesn't=
> >  even show paved hard shoulders locally for cyclists.<br><br>Rendering loca=
> > lly Maperitive does a nice job and you can configure what is rendered and h=
> > ow it is rendered.<br>
> ><br>Routing programs use the directional arrows to see if the junction can =
> > be navigated.<br><br>I think step one is get the information in the map, st=
> > ep two is rendering.<br><br>Cheerio John<br><br>&gt;<br><br>Hi Rosscoe,<br>
> >
> ><br>
> > Supt_of_Printing has sent you a message through OpenStreetMap with the subj=
> > ect intersections:<br>
> ><br>
> > =3D=3D<br>
> > Well if someone can explain to me what is actually wrong with smoothing=20
> > out the chunky jagged curves on intersections, the useless street names=20
> > on slip lanes, etc., the useless over-abundance of directional arrows=20
> > for every little bit of the intersection where the direction is quite=20
> > obvious (making the intersection look messy), crossovers in median=20
> > strips matching the intersecting roads rather than the road it is=20
> > actually in, etc., etc., etc., I may get it! But surely the aim is to=20
> > give a professional and clear non-confusing look to the roads on the=20
> > finished product rather than how it looks on the potlatch editing mode. I
> >  would rather the editing mode looks like a bit of a dog&#39;s breakfast so=
> > =20
> > that the finished product doesn&#39;t!<br>
> ><br>
> > And yes, I have read the thread on intersections. Perhaps someone can=20
> > point me to the rules that says&amp;quot;there should only be two=20
> > through carriage ways in both directions and the slip ways at the=20
> > sides&amp;quot; as this doesn&#39;t reflect reality, as there is not two=20
> > through carriage ways with a big square&amp;quot;island&amp;quot; in=20
> > the centre of the intersection on the ground.<br>
> ><br>
> > I will continue to edit to get the roads and intersections to look=20
> > professional, reflecting reality, rather than the confusing, chunky=20
> > rendering with an over-abundance of arrows and street names that I so=20
> > often come across.<br>
> ><br>
> > Supt_of_Printing
> >
> > --e89a8f503964a7bd1204b2cdfe5b--
> ==
>
> You can also read the message at http://www.openstreetmap.org/message/read/227056
> and you can reply at http://www.openstreetmap.org/message/reply/227056




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