[Talk-us] Name tag on unnamed, but numbered routes

[Minh Nguyen]

Vào lúc 06:44 2021-11-16, Brian M. Sperlongano đã viết:
> There was a discussion on Slack this morning that could use a wider 
> perspective.  The question is what, if anything, should go in the "name" 
> tag for numbered routes in the US that don't have any other name.
> 
> One convention is to make a "constructed" name from the route number, 
> for example, "VT Route 17" or "Highway 12" or something along those 
> lines to put in the name tag.  Arguments for this usage include signage 
> that contains these constructed names, for example at intersections with 
> other roads.
> 
> Another convention is to have the name tag be omitted, perhaps also with 
> noname=yes for unnamed numbered routes.  The argument for this usage is 
> that name is only used for names, and ref is only used for route 
> numbers, and that constructed names are "mistagging for the renderer".  
> For transparency, this approach (no name tag) is my preference, however, 
> in my area, unnamed numbered routes are rare with the exception of 
> Interstate highways.

A systematic name is still a name, even if it's derived from a route 
number. It would merely be tagging _redundantly_ for the renderer to use 
name=* for this purpose. It would be _mistagging_ for the renderer to 
tag name=VT Route 17ᴬ, with a superscript A just because the A is 
conventionally set in smaller type on signs in Vermont.

There's no consistent standard on how a route number makes its way into 
a town or county's addressing scheme, so any idiosyncrasies should 
definitely go in name=* to avoid dataloss. My go-to example is "West 
United States 22 and 3", which is part of eastbound U.S. Route 22 and 
northbound State Route 3. [1]

In practical terms, here's how I figure:

* It's difficult for a data consumer to derive the name from just the 
way ref or route relation, based on diverse rules that vary from state 
to state or even by county. It is possible to develop a lookup table 
[2], but only to use it as a fallback when no name is tagged.

* It's relatively easy for a data consumer that doesn't need the extra 
detail to omit the name when it's redundant to the ref. Looking for a 
matching number goes a long way.

The data consumers I have in mind are renderer styles that show shields, 
renderer styles that intentionally don't show shields, geocoders, and 
navigation applications (especially voice guidance).

[1] https://www.openstreetmap.org/way/535853084
[2] https://w.wiki/4RBc

-- 
minh at nguyen.cincinnati.oh.us