[Talk-us] Announcing progress: Minnesota Highway classification project publishes first guidance

[Bob Gambrel]

Yes, it is true almost everyone uses email. I can't live without it! I am
using email to reply to this message.

Trolltag: apparently there is a wiki definition about it!
https://wiki.openstreetmap.org/wiki/Trolltag  I think that is my new word
for today! Seriously, I did not know that was a thing!

Thank you for the definition of "freeway". I know I used the term a
lot informally. I was about to say that it wasn't clearly defined in OSM,
but fact checked myself. When I search the wiki for it I get the
highway=motorway page. And in US it is one of several terms used for things
that should be tagged motorway. (As are turnpike and interstate). I
personally try to avoid it because I suspect there is some extra meaning in
the word (as there is obviously in both interstate and tollway).

I am trying to understand your distinction in the last sentence: "If a
segment ends with an at-grade junction, it's still an expressway, but the
motorway ended with the previous junction." I guess I am confused by
"previous junction". We have to make a lot of calls in our mapping about
where to end a highway=motorway. The guidance we have settled on is the
first at-grade intersection. (I suspect at-grade is not defined either,
sighs.)  Are you saying there is a better place (the "the previous
junction")?  (Assume in your answer that the motorway is long enough to be
considered one.) Where exactly should it end? I am really new to motorway
tagging so this is a serious question. An example would be nice. Does the
guidelines as written in the Minnesota page a good guideline? Below is the
snippet. I hope it shows up for you.

*Where does the motorway island end?* Consider each end of the island
independently. For each end, as long as the other physical attributes
apply, the end of the motorway island will be delimited by the first at
grade intersection encountered. If the first at grade intersection for both
sides of the divided highway is the same, then that is where the end should
be marked. But what do you do if one carriageway has an intersection that
is not shared by the other carriageway? If you applied the rule to each
carriageway independently then one of motorway's carriageways would be
longer than the other. The consensus in a discussion in the
#highway-classification channel of slack seems to be that the longer one
should be truncated to match the shorter one.
<https://wiki.openstreetmap.org/wiki/File:Example_of_where_to_end_a_motorway_island.jpg>
<https://wiki.openstreetmap.org/wiki/File:Example_of_where_to_end_a_motorway_island.jpg>
Example of where to end a motorway island.

On Thu, Jan 27, 2022 at 1:40 PM Paul Johnson <baloo at ursamundi.org> wrote:

> On Thu, Jan 27, 2022 at 1:27 PM Bob Gambrel <rjgambrel at gmail.com> wrote:
>
>> Several points were made above and will try to address them here.
>>
>> 1) Paul says: "Pretty sure there wasn't more input because everyone uses
>> email, but not that many bother with Slack." Evin says: " I find it to be a
>> better communication platform for discussing OSM related issues than this
>> archaic mailing list."  Just an opinion:  I too, find Slack to be a very
>> useful and capable mechanism. I also read what is in talk-us but rarely
>> post. While I have used email all my life and find it useful for some
>> things, I find Slack very good for capturing, saving, and sharing thoughts.
>> I do believe that one's "favorite communication mechanism" is very personal
>> and there are many, so I am not trashing one or another. And I am not here
>> to defend Slack, as there are very strong opinions about it both ways.
>> Regarding the bigger issue: should we be trying to use other channels to
>> communicate? Yes. It was suggested (in Slack) that I reach out through
>> Talk-us to gather more opinions. That is why I did the post, and it is nice
>> to be picking up those opinions. To-date I have also used OSM to attempt to
>> reach out (messages and changeset comments). I plan to try additional
>> reach-out in the next day or so.
>>
>
> I said this also because literally everyone uses email.  I'd actually
> surprise me if you didn't need email to sign up for Slack.
>
>
>> 2) Paul says: "Motorway islands?  You mean a grade-seperated exit on an
>> expressway?" I did not define motorway islands. I am just using common
>> lingo that I have seen often, especially in the "#highway-classification"
>> channel and in the US wiki. It is reasonably well defined in the US
>> reclassification page if you have not looked there. The Minnesota page
>> points to that page. I do not especially mean a "grade-seperated exit on an
>> expressway"  The term expressway is also defined on the US page and
>> Minnesota adopts that usage. I am talking about a motorway segment
>> (highway=motorway) as defined by the OSM wiki, that is relatively short (a
>> few interchanges), that meets all the requirements of a motorway, and that
>> connects on both sides to something that is not a motorway.
>>
>
> OK, thank you for clearing that up.
>
>
>> 4) I really don't know what you (Paul) mean by a troll tag. Not in my
>> lingo.
>>
>
> Something a data consumer has to parse extra data for in order to clear up
> an ambiguous tag.
>
>
>> 5) Evin says: "As for motorway islands, I don't see anything wrong with
>> these as long as there's not just one interchange sandwiched between at
>> grade interesctions. I think everybody can agree that it's bad tagging to
>> tag a road as motorway when there's only one interchange. I change these
>> back to trunk whenever I come across them without hesitation." We in
>> Minnesota did not agree that it's bad tagging. I will share this opinion on
>> the channel and see what folks think.
>>
>
>
>> 8) Evin says: "it's certainly possible for a freeway to end at an at
>> grade intersection. That's the best place to end a motorway; anything else
>> would just seem arbitrary." Again, I don't use the term freeway so won't
>> weigh in. There seems to be a lot of consensus that an at grade
>> intersection is a good place to end a motorway. Minnesota adopts that
>> position.
>>
>
> Basically freeways (motorways) are a subset of expressway.  Expressways
> can have ramps.  They can have at grade intersections.  Freeways don't have
> at-grade intersections.  If a segment ends with an at-grade junction, it's
> still an expressway, but the motorway ended with the previous junction.
>
>>
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