As a background, my state in Australia does not name its on-/off-ramps. They can either be continuations of the prior roadway, or they can be unnamed sections of road, depending on how the law describes them. But, always, there is never a street sign stating, e.g., “Hume Highway On-ramp”. Despite this, someone has used name=Hume Highway Onramp and similar on a number of these roads. I’m going through and fixing these - if the road is legally named I will name it accordingly, or I will set noname=yes. Either way, I plan on adding a description tag, describing the roads that the ramp is connected to.
I plan on using the following format for the description: description={Road From} {Direction}–{Road To} {Direction}. For example:
description=Hume Highway E–Yass Valley Way S
description=Hume Highway W–Collector Road (as the ramp connects directly to both directions of Collector Road).
Is any of this information useful, or will most map routing software be able to handle that without the descriptions? And if it useful, what should I do for roads that cannot be easily classified into north/south/east/west? E.g., the Hume Highway goes between Sydney in the Northeast and Melbourne in the Southwest, but the road is quite windy and there are portions which are east-west and portions which are north-south, and portions which are in between.
Edit: Could also do description=Hume Highway Melbourne–Collector Road which would unambiguously refer to a direction, but could be confused with other identifying information.
generally, for OpenStreetMap there is no need for signs, and names do not have to be legally binding, they are just the most common name for a thing. But they are also not just descriptions, so in this case, from remote, it seems there isn’t a name and these descriptions should go. Have you asked the person who put it?
destination=* tags are specifically for “the content of signposts or ground writing” and “refer to road signs that the driver actually sees”. What I describe is not an appropriate use of the destination=* tag, because there are no signposts or ground writing.
destination tags is what gets used by navigation apps.
You may certainly choose to come up with a format to put in description, but it will not be used by any routers that I know of.
Further, it is generally a poor idea to create compound tags using a specific text formatting of some other values. The formats will generally not be consistent between regions of the world, and any interested data consumers would probably prefer to get Road From, Direction, Road To, Direction as separate tags that they can use or format as they see fit.
(Including “Road From” in formatted descriptions also strikes me as rather redundant, since any router would surely know what road they’re turning off from.)
You may wish to also inquire specifically on the Oceania subforum if there are any local Australian tagging norms to be aware of.
If these roads have neither a name, nor a destination sign on them, I’d not put any tags.
You could put names of the roads at the start and end of the way to something like description as you propose - But information in description tags is notoriously difficult to interpret by any software and if it’s just “Start Road to End Street”, this information could easily be extracted from the names of the respective roads without the need for any tag.