[Talk-us] US Trunk road tagging

[Minh Nguyen]

Vào lúc 11:11 2021-05-05, Evin Fairchild đã viết:
> On Wed, May 5, 2021, 9:44 AM Minh Nguyen 
> <minh at nguyen.cincinnati.oh.us 
> <mailto:minh at nguyen.cincinnati.oh.us>> wrote:
> 
>     NHS is itself a functional road classification scheme, just not one
>     that
>     maps cleanly to other classification schemes, because it's very
>     explicitly about funding. The law literally says which streets are part
>     of the system.
> 
>     Tagging the entire NHS, sans Interstates, as highway=trunk would result
>     in basically every signposted local truck route becoming a trunk road.
>     (As in MUTCD R14-1, not M4-4.) It wouldn't technically add much
>     information to the map, because NE2 already went around tagging
>     NHS=* on
>     the whole system as it was back then.
> 
>     It would be more reasonable to tag the Other Principal Arterials class
>     as highway=trunk, but NHS is not the only scheme that includes an Other
>     Principal Arterials class. That terminology comes from the FHWA's
>     Highway Functional Classification system. It's unlikely that Congress
>     and FHWA agree on every individual principal arterial
>     classification, so
>     there could still be persistent disagreements about highway=trunk.
> 
> 
> I am not suggesting to tag *every* route that is on the NHS as trunk.
> 
> To be clear, my proposal is to tag only NHS routes that are on state and 
> US routes. Also, I don't think we should include intermodal connectors 
> either. That will hopefully cut down on the number of NHS routes in 
> urban areas.

For sure, this would be more reasonable than tagging the whole NHS as 
trunk. How different would it be from basing trunk on Other Principal 
Arterials instead? That would simplify the decision tree further and 
make it more reliable. We already have a hard enough time maintaining 
state route relations as state routes get realigned and redesignated. 
For all of the difficulties this community had dealing with NE2, that 
was one thing they did quite reliably that has been hard to keep up over 
the years.

I'm still wary of relying on NHS or any other purely legislative process 
as the primary source for classifying roads. European craft mappers must 
love the idea that we'd allow Washington lobbyists to directly influence 
our road classifications. At least with FHWA and AASHTO decisions, we 
theoretically map according to the signs rather than the decisions 
themselves.

>     Lately there's been a lot of discussion about an Americentric renderer
>     on OSMUS Slack. [1] It's an idea OSMUS has been kicking around forever,
>     but the enthusiasm around highway classification and shields may help
>     make it a reality.
> 
>     It would be feasible for an Americentric renderer to apply an
>     orthogonal
>     rendering style to expressway=yes, but I'm sober about the ability of
>     such a renderer to resolve highway=trunk disputes on its own. After
>     all,
>     osm.org <http://osm.org>'s openstreetmap-carto style is still the
>     front door for mappers
>     everywhere. Maybe better editor support could help tip the scales, but
>     expressway=yes may be a hard sell to globally relevant editors and data
>     consumers, being so peculiar to the U.S.
> 
>     [1] https://wiki.openstreetmap.org/wiki/United_States/Map_style
>     <https://wiki.openstreetmap.org/wiki/United_States/Map_style>
> 
> 
> 
> That's interesting; it would certainly nice to have a US-centric 
> renderer if only to show route shields, but it would definitely be great 
> to have it render the expressway=yes tag. There would probably be less 
> need to have trunk be representing expressway.

At Mapping USA in a couple weeks, we'll have an initial roundtable 
discussion about the development of an Americentric renderer. Please 
register and bring your perspective to the table! 
https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA

-- 
minh at nguyen.cincinnati.oh.us