[Talk-us] [Talk-us-newyork] Highway classification guidelines for New York State

Minh Nguyen minh at nguyen.cincinnati.oh.us
Sat Sep 11 23:48:22 UTC 2021


Thanks for your thoughtful review of Kevin's proposal, Jason! Some 
clarifications inline:

Vào lúc 15:43 2021-09-11, Jmapb đã viết:
>  > 6. highway=unclassified
>  > 7. highway=residential
> 
> I feel the proposal gets into some murky territory by basing
> highway=unclassified on commercial traffic. There has always been a
> highway hierarchy with unclassified at the bottom rank, and then
> residential below that, ie, not ranked at all. Unclassified is for the
> most minor roads that link locations, residential is for public roads
> that don't. How these classifications are mapped to reality varies
> wildly over the globe (the names themselves are nearly meaningless) but
> the suggestion that we should choose between these two classifications
> by the *type* of traffic carried -- not by the role in linking
> locations, the amount of traffic, the distance covered, or the road's
> routing prominence -- seems like a sharp departure from tagging norms.

It seems you're referring to this line:

> Streets in urban areas that serve commercial or industrial districts and do not have a higher classification should also receive highway=unclassified.

This is reminiscent of the rule of thumb that gets tossed about often, 
something about downgrading highway=unclassified to highway=residential 
once there are a certain number of houses per mile -- specifically 
houses. The wiki has a much more convoluted definition for both 
highway=unclassified and highway=residential, so I don't know where that 
simpler formulation comes from; it might just be urban lore. Personally, 
I've never been particularly keen about classifying roads based on 
something that could just as well be captured in the abutters=* key. You 
may be interested in a separate proposal for highway=street that would 
do away with any distinction between unclassified and residential roads. [1]

>  > Expressways
> 
> Re "Grade-separated interchanges (access_control=full,
> access_control=partial)", these are undocumented tags. What do they
> mean? Are they part of this proposal?

access_control=* refers to the degree to which traffic is able to enter 
from side streets and driveways, as in "controlled-access highway" or 
"limited-access highway". If I'm not mistaken, it was originally coined 
by NE2, a former regular on this list, to indicate a super-two. [2] More 
recently, it has come up as a more straightforward alternative to 
expressway=*, though the two keys indicate somewhat orthogonal concepts. 
[3][4] At this point, with over 10,000 uses, access_control would 
qualify as "in use" once someone gets around to writing a wiki page for it.

>  > Memorial and symbolic highway names
> 
> Both honorary_name and memorial_name are in use and seem more correct
> for this purpose, so why is official_name preferable? Personally I like
> honorary_name because it would cover non-memorial situations, eg, where
> a living person's name is used. (Currently memorial_name has more uses,
> but they're all the same road, "USS Indianapolis Memorial Highway".)

Is there an example where a road would have both a memorial name (the 
term used by the MUTCD) and some other kind of official name, where the 
distinction is important enough that we wouldn't want to just dump the 
two names in official_name, separated by a semicolon? I'm aware that a 
road may have multiple official names of various kinds, but the 
distinction may be so minor as to create headaches for mappers in other 
contexts, similar to how we've had to split hairs between unclassified 
versus residential.

Many data consumers handle name keys in the same manner regardless of 
feature tag. Despite being used orders of magnitude more often, 
official_name is also relatively poorly supported by data consumers. Are 
there things other than roads that also need to maintain this 
distinction between memorial and official names? It would be unfortunate 
if, in a quest for precision, we relegate these names to a key that 
would go mostly unconsumed.

[1] https://wiki.openstreetmap.org/wiki/Proposed_features/highway%3Dstreet
[2] https://lists.openstreetmap.org/pipermail/talk-us/2011-May/005967.html
[3] 
https://wiki.openstreetmap.org/wiki/Talk:Key:expressway#Applicability_to_Super_Twos
[4] https://lists.openstreetmap.org/pipermail/talk-us/2021-May/021069.html

-- 
minh at nguyen.cincinnati.oh.us




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