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

[Bob Gambrel]

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.

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.

3) There is much debate and it is probably "unsettled law" about how to
handle motorway islands. The debate seems to center on several criteria: a)
how long is it, b) how many interchanges, and c) where to end. I suspect
the debate will go on for the life of OSM. We, in the Minnesota effort,
asked around (in Slack), got opinions, offered our own thoughts, and agreed
on the guidelines as documented. Basically: length does not matter, at
least one interchange, and end at first at-grade intersection. Are there
other possible conclusions: yes. Might other people do it differently: yes.
Is it perfect: no. What we have done in the wiki is document it. Is it
changeable: yes.

4) I really don't know what you (Paul) mean by a troll tag. Not in my
lingo.

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. Maybe we
should revisit that decision. As you are a Slack user you could join that
channel (if you aren't already) and start a thread about that opinion.
Please do so: the result could be either re-confirming the approach we are
using or changing it. (And: please don't change in Minnesota without having
the discussion. The US guidance, if I recall, was to not change existing
motorway tagging without discussion. And cite that discussion as reason for
the change.

6) Evin says: "there are many valid cases where a road that is an
expressway upgrades to motorway for just 2-3 (or more) consecutive
interchanges, for example an expressway in a rural area that upgrades to
freeway when it bypasses a town and has at least two interchanges providing
access to that town, and this should be tagged as motorway."  We have been
careful to use the term expressway (expressway=yes) only in the way as
defined in the US wiki page. We do not use the term "freeway" because it is
not defined. (The term is used but is not defined so I tend to avoid it.) I
think, though, you are just giving a good example about when a motorway
island is appropriate. I don't think we disagree. By the way, as explained
in our wiki page, there was only one place in Minnesota where
expressway=yes was used. Analyzing the definition, we felt it was wrongly
used.

7) Evin says: "The only thing that should be clarified on the MN highway
classification page is that we shouldn't have sections of motorway with
just one interchange." See reply to 5 above.

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.

This is only the first time I have ever tried to do a reply in Talk-us.
Hope it ends up there.


On Thu, Jan 27, 2022 at 12:32 PM Paul Johnson <baloo at ursamundi.org> wrote:

> On Thu, Jan 27, 2022 at 12:21 PM Evin Fairchild <evindfair at gmail.com>
> wrote:
>
>>
>>
>> On Thu, Jan 27, 2022, 9:34 AM Paul Johnson <baloo at ursamundi.org> wrote:
>>
>>>
>>> Motorway islands?  You mean a grade-seperated exit on an expressway?  I
>>> can't see a compelling reason to not just tag that the same as an
>>> expressway (since junctions can be a mix grade separated or at grade) any
>>> more than it makes sense to tag motorway all the way to an at-grade
>>> junction (which turns motorway into a trolltag).
>>>
>>
>> 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.
>>
>> However, there are many valid cases where a road that is an expressway
>> upgrades to motorway for just 2-3 (or more) consecutive interchanges, for
>> example an expressway in a rural area that upgrades to freeway when it
>> bypasses a town and has at least two interchanges providing access to that
>> town, and this should be tagged as motorway. I've never seen a problem with
>> this.
>>
>
> Right, I can understand this, that's something that comes up around a lot
> of midsize (5000ish) population towns across America.
>
>
>> The only thing that should be clarified on the MN highway classification
>> page is that we shouldn't have sections of motorway with just one
>> interchange.
>>
>> Also, why is it bad to have a motorway end at an at grade intersection?
>> How does this turn motorway into a "trolltag" (lol)? I've explained my
>> position on this many times and I'd like to hear yours.
>>
>
> Except for highly unusual, rarely used and heavily restricted cases,
> freeways don't have at-grade intersections.  Expressways do.  If you have
> an at-grade intersection on what you're looking at, and it's perfectly
> legal to cross, enter and leave the highway there, you're not looking at a
> freeway.
>
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