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

[Ian Nicholson]

So as someone who’s not extremely versed on this: if we assume that motorways should not end at at-grade intersections, how should US-61 be tagged where it intersects with I-90 at Dakota (this is where I-90 turns away from the Mississippi and heads west in the south half of Winona County)?
61 has on/off ramps several hundred feet north of the split, but about a half mile to mile north of the ramps there is an at-grade driveway to the southbound lane and about a half mile north of that there is a turn lane where the northbound lane can access a frontage road.
Apologies I realize this is basic but I’ve just had a difficult time getting my head around these tags. 

Sent from my mobile device, please forgive any errors in my spelling or grammar.

> On Jan 28, 2022, at 11:47, Bob Gambrel <rjgambrel at gmail.com> wrote:
> 
> 
> Thanks Paul. I will post your thoughts. Thanks again for your insight
> 
>> On Fri, Jan 28, 2022, 11:04 AM Paul Johnson <baloo at ursamundi.org> wrote:
>>> 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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