[Talk-us] US Interstate exit junction exit_to tag

Mike N niceman at att.net
Mon Mar 28 17:13:50 BST 2011


On 3/28/2011 11:56 AM, Alan Mintz wrote:
> At 2011-03-08 06:03, Mike N wrote:
>> The "Motorway Junction" tag at
>> http://wiki.openstreetmap.org/wiki/Motorway_junction has recently had
>> the exit_to tag added. Old interstate tagging advice at
>> http://wiki.openstreetmap.org/wiki/Interstate_Highway was to put exit
>> sign destinations in the "name" tag. However this is not exactly
>> correct, especially for the case of highways with named exits.
>
> Can you give examples for what is a "named exit", versus the other kind?

The Pennsylvania Turnpike contains some of these - an official name + 
destinations for exit_to:

http://upload.wikimedia.org/wikipedia/commons/c/cd/PA_TPK_WB_at_Mid-County.JPG

> http://help.openstreetmap.org/questions/3529/why-should-or-should-i-not-use-ref-on-links/3723
> .
>
> In the case of moving some of the name=* values to exit_to=*, I noted
> that the name=* values are being rendered by Mapnik and Osmarender, and
> asked whether those (and others) have been modified to use exit_to=*
> instead, to which one user replied "don't tag for the renderer". While I
> understand that concept, it seems to me that the renderer was apparently
> designed to agree with the current schema, and I'm just asking if
> everyone wants their exit names to stop being rendered until someone
> decides to fix the renderers?

    It's more likely that the renderer has a general rule to render a 
'name=' tag for any object, regardless of what it is.   I've used this 
in the past to force a name to appear where the actual tagging wasn't 
rendering.

    A different way to ask the question is does it make sense to render 
the exit_to at any time?    The most likely use of the information is by 
navigation utilities - where the actual map rendering will be much more 
sparse to limit information to only that which is needed for driving. 
And exit_to information might be displayed separately and/or spoken.

    The counterpoint to having exit_to being rendered is that most 
people are only interested in exit numbers when reading a visualized 
map.   In congested areas, the rendered exit_to information is extremely 
overbearing and distracting compared to the surrounding roads.  In such 
cases, the compact ref= and name= (for named exits) results in a much 
cleaner map.




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