(Been away for a while; missed a lot of discussion for a topic that’s important to me…)
This matches my understanding perfectly. An understanding gleaned from studying the wiki at various levels, studying common practice, and simply what seems to make sense to me.
As I think I’d mentioned, tertiary is for roads more “significant” than run-of-the-mill unclassifieds; suitable for going longer distances, and/or to multiple destinations. In another post, I think GnasherNF gave examples essentially backing this up. Note that in many areas, there are no “settlements”, thus no roads needed to connect them, but that doesn’t mean there are no tertiary-suitable roads. There may be gas plants, pulp mills, significant bridges, etc. A road crossing a rarely-bridged river easily qualifies as tertiary to me. A road with a nice curve instead of a corner, built for more traffic, again likely tertiary. It’s a judgement call.
Trying to push toward closure… I’d wholeheartedly support updating the wikis with these images as examples. How do we make decisions here? Here’s my vote.