[Talk-us] Mass Change of Highway Classification in Larimer County Colorado

[Paul Johnson]

You're trying to tag by network for the renderer.  We already have a
specific tag for that, though:  network=* and it's on every route=road
relation we have.  What you're looking for is already solved and
doesn't need the highway=* tag at all, just the relations and member
ways.

On Tue, May 4, 2021 at 7:51 PM Brian M. Sperlongano
<zelonewolf at gmail.com> wrote:
>
> The whole point of the highway classification values is to capture the hierarchical network of roads.  Renderers rely on the hierarchical nature of the classification values to make decisions about which zoom levels to show different roads at.  Trunk/primary/secondary/etc, are not, repeat, ARE NOT, proxy tags for the number of lanes on a road, whether or not the road is divided, the speed limit, or the presence of stop lights, shoulders, intersections, or sidewalks.  There are separate tags for all of these things.  Don't abuse highway classification for tagging the fact that a road has high speeds or lots of lanes.
>
> Regarding:
> > roughly subjective based on network, size and character like we have been.  It works.
>
> No, it does not work, and this attitude is why highway classification tagging in the US is (a) cartographically broken, (b) has no defined standards that mappers can use and (c) results in constant edit wars and hurt feelings (the origin of this thread being case in point).
>
> Let me show you why it's broken.  Take a look at the OSM map at zoom 7 around Oklahoma[1].  Mappers have changed the highway classification of the roads in that area based on their physical characteristics.  At zoom 7, OSM shows trunk and above, and thus US 50 and US 54 pop into and out of existence based on the whims of local mappers.  The result is an entirely avoidable cartographic dumpster fire.
>
> In comparison, our competitors[2,3,4] keep routes together, which results in route continuity at all zoom levels, *regardless of physical characteristics*.
>
> [1] https://www.openstreetmap.org/#map=7/36.829/-101.285
> [2] https://www.google.com/maps/@36.7823325,-99.7599754,7z
> [3] http://mapq.st/2dypPbv
> [4] https://www.bing.com/maps?cp=35.95416~-99.784913&lvl=7
>
> In order to solve this, we need to let go of the idea that physical characteristics have any bearing on highway classification.  I don't care that there are examples of state routes that have higher speed limits and more lanes than US highways in some cases.  I don't care what NE2 tagged in the past.  At a map zoom level that shows multiple cities, it should show the major routes between the cities, regardless of the quality of those roads.  At higher zooms, the map should show the major routes between smaller towns and cities, and so forth.
>
> For this reason, US highways should always be trunk, regardless of their physical characteristics.  The reason they are US highways is because they provide long-haul connectivity between cities and they should appear at lower levels of zoom than other roads, based on their importance in connecting cities.  Likeways, state routes should be at the next level of importance, followed by county roads in places where those exist.  Subjective judgements about road network connectivity importance should be limited to the lowest classification categories where we don't have routes to go by.
>
> I would advocate for US definitions that look something like this:
>
> motorway:
> - Signed interstate highways
> - Any other controlled access, grade-separated, divided highway built to interstate or near-interstate standards for a significant length
>
> trunk:
> - US highways
>
> primary:
> - Numbered state highways
>
> secondary:
> - For states that have them, county roads; otherwise, the most important named roads that provide connectivity between higher classification roads and lower-classification roads.
>
> tertiary, unclassified:
> - Lesser named roads that provide connectivity between secondary roads and residential/service/track roads, where the more important roads are tertiary and the less important ones are unclassified
>