It seems that on Tag:highway=service , there is a note ;

, but a service road IS a frontage road according wikipedia and a service road is parallel to a bigger road
so, why not making also a highway=side_road for tagging ‘minor’ streets/roads on Special road types and maybe also highway=driveway , because , if one now want to map a driveway, one has to map a ‘combination’ of highway=service + service=driveway …

…but not in OSM. As we’ve explained many times before, OSM definitions may not exactly match Wikipedia or dictionary definitions for many reasons. I don’t understand why you keep wanting to change the meaning of tags that have been in use for up to 15 years.

…because the difference isn’t notable enough to warrant separate tags. For the “minor” roads, you can use highway=residential if there are residences along it, or highway=unclassified if there aren’t. There’s no need to add another level in between these and service.

As for highway=driveway, again, the difference between a driveway and a typical service road is so minor that there isn’t any point making it its own tag. A driveway is a service road, just with a slightly more narrow definition.

If this is OT please let me know and we can continue elsewhere, but since it touches on another discussion I was having:

Is there a settled OSM approach to this question of when to break a key into different levels? They seem to crop up a fair bit.

Personally I think they’re nearly always redundant: imo any classification hierarchy ought to locate itself in the index of objects classified, ie, the wiki, not in the objects themselves.

I’m not sure I completely understand what you’re referring to. Do you mean something like having highway=service and making a case for splitting that into highway=service_major and highway=service_minor? I don’t think there’s a set policy. It all depends on whether one can make a good enough case regarding why the current state isn’t working and how such a change would benefit the contributors and data consumers. Using henke54’s service roads as an example, I don’t see any problems with the current tags or how changing them would benefit anyone.

Sorry: the reason you don’t completely understand is that I completely misunderstood your point: by ‘no need to add another level’ I conclude you meant no need to add another grade of road and keep splitting the rainbow finer.

So now I really am OT - I’ll PM you.