Highway ref's with long modifiers should be rendered

[elijahmathews]

Expected behavior

Highway ways should have the values of their ref tags rendered.

Actual behavior

Highway ways with ref tags that contain long modifiers (e.g. ref=US 81 Business or ref=ND 200 Alternate) are not having their ref's rendered. They are rendered if the modifiers are abbreviated (e.g. ref=US 90 ALT), but that probably goes against the no abbreviations convention.

Some abbreviations that are known to be used:

• ref=... Business ➞ ref=... BUS or ref=... Bus
• ref=... Alternate ➞ ref=... ALT or ref=... Alt
• ref=... Bypass ➞ ref=... BYP
• ref=... Truck ➞ ref=... TRK

Links and screenshots illustrating the problem

In Grand Forks, ND, 32nd Avenue South is (probably correctly) tagged with ref=US 81 Business but has no ref rendered, unlike the nearby interstate with ref=I 29;US 81:

Meanwhile, in East Bernard, TX, Main Street is (probably incorrectly) tagged with ref=US 90 ALT and has its ref rendered as expected:

[imagico]

Length limit is 11 characters, determined on the longest ref:

openstreetmap-carto/project.mml

Line 1735 in b86de31

WHERE height <= 4 AND width <= 11

The concern about this creating bad mapping incentives is valid, i am not sure if the solution can be to maintain a list of abbreviations in all languages of the world (at least not within this style - it could be a valuable idea for a separate project - like also for abbreviations in other labels like street names). The alternative would be to apply some generic shortening using an ellipsis like suggested for addresses already: #4160 (comment)

[elijahmathews]

I suppose even if there were to be some sort of abbreviation lookup table that was used solely for the purpose of rendering highway ref's, that wouldn't necessarily negate bad mapping practices as mappers would presume the displayed labels' format (i.e. a rendered label along the lines "US 81 BUS") is exactly how the ref values should be formatted (i.e. ref=US 81 BUS rather than ref=US 81 Business). The ellipsis (or even just a period) method would probably be better in that case since it would make it clearer there's an abbreviation taking place, although some modifier abbreviations wouldn't work as well in that scheme (e.g. "Truck" is probably better abbreviated as "Trk..." or "Trk." rather than "Tru..." or "Tru.").

To me, perhaps the best scenario would be to add a new tag along the lines of ref:abbr=* (and multilingual versions like ref:es:abbr=*) to allow mappers to explicitly set the abbreviated version of the ref, which renderers would look to first if it's used or else defer to ref. However, this would mostly add redundant information to the map, you'd still get some ref:abbr values that would probably exceed the 11 character limit (e.g. if a hypothetical but not that unreasonable highway ref:abbr=ND 1804B ALT existed), and it necessarily enforces one particular abbreviation scheme.

[Adamant36]

To me, perhaps the best scenario would be to add a new tag along the lines of ref:abbr=*

There's currently the tag short_name for abbreviated names. Short_ref also exists, but unfortunately it only has 7 uses. That said, it might be worth turning into a proposal and advocating somewhere for wider usage of it.

[ZeLonewolf]

Note this would be made redundant if #508 is implemented.