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

[Paul Johnson]

On Fri, Jan 28, 2022 at 9:43 AM Bob Gambrel <rjgambrel at gmail.com> wrote:

> I really want to be clear about your position so I do not misstate it in
> the channel. I know you have already covered it but if I try to piece it
> together from the thread I might get it wrong. Am stating what I think your
> position is. Let me know if I got it right ...
>
> 1) Barring exceptional edge cases ...
> 2) A motorway should not end/start at an at grade intersection
> 3) A motorway should start/end  where a ramp touches the carriageway
>
> I cannot remember in the long thread whether you weighed in about the
> length of a motorway island. Following are questions about that. The slack
> discussion that Evin initiated is more about item (a) below and I want to
> make sure your thoughts enter that discussion ...
>
> a) Do you believe there is a minimum number of (non at-grade) interchanges
> there should be before we classify something as a motorway? For example, is
> a one interchange motorway island ok?
> b) Do you have any particular concerns about the minimum length of a
> motorway island?
>

It's a little hard to quantify, but generally speaking I'm not inclined to
step it up for just one exit, even on long sections, mostly because people
expect freeways to be fully controlled, without at-grade access, and at
least two carriageways.  This mostly leaves "places with a grade-separated
junction" as the closest handy transition point.  I'm generally hesitant
about setting something to motorway if it's not a fairly clear case of
motorway.  Short islands of motorway often fall into the category of
mapping the DOT's not-fully-realized aspirations for a freeway, in which
case it may be useful to ask if "proposed=motorway" and "expressway=yes" in
addition to a lower highway value is highly likely to be more closely
accurate.  I don't have a MN example offhand but being able to quickly
distinguish the difference could mean, in PA for example, consumers taking
I 76 instead of the immediately adjacent and not-quite-a-freeway US 212
when routing for shortest time, absent all other tags.

I hope you don't think I am being picky here. I really want to get your
> thoughts into the discussion, if you don't join it yourself.
>

You're fine.


> To recap the current guidlines in Minn: motorways islands have no minimum
> length requirement, can consist of as few as a single interchange, and end
> at the first at-grade intersection.
>
> On Fri, Jan 28, 2022 at 9:14 AM Paul Johnson <baloo at ursamundi.org> wrote:
>
>> On Fri, Jan 28, 2022 at 8:44 AM Bob Gambrel <rjgambrel at gmail.com> wrote:
>>
>>> I think we are near the end of this talk-us thread. Both Evin and Paul
>>> have provided input along the way and I have responded as well. A few
>>> others added insight as well. As a result of this there is a newly opened
>>> discussion the the Slack #local-minnesota channel addressing this issue.
>>> Evin has initiated the discussion there. Other active
>>> highway-classification mappers are joining that discussion. Others who have
>>> joined this talk-us discussion are on Slack and are aware of the
>>> #local-minnesota channel so can participate as they see fit in that
>>> discussion.
>>>
>>> Paul: I want to make sure your views are discussed there. If you want to
>>> join that discussion please do. If not can you summarize your bottom line
>>> opinions about what the wiki says now that you disagree with. You can
>>> provide them here or within the wiki discussion page. I am asking this now
>>> because it is possible that your views have changed since the beginning of
>>> the thread. If you post your views here I will transcribe them to Slack so
>>> the others can know what they are.
>>>
>>
>> I think I already covered it.  Only significant concern being the
>> motorway part.  Barring some truly exceptional edge cases, I don't think we
>> should be hinting to consumers to expect a freeway heading into an at-grade
>> intersection, particularly when such a situation is something I think
>> everyone would expect to happen on an expressway.
>>
>
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