Firstly, thanks Paul, for an excellent recap of the history and problems we currently face.
Its difficult not to write reams of examples where we have anomalies in the way roads are tagged, and Ill try to get over the main issue as I see it, concisely.
I agree we have many examples of where faster (eg, bypass) roads, carry a classification lower than the old road they replace. And I know it makes no sense to show a primary going through the centre of a city, where the tertiary bypass is clearly faster. Naturally a “dumb GPS” is going to take you through the city. However, I do deal with this situation by ensuring the urban sections carry the correctly tagged speed limits, which should force the electronic devices to send you down the bypass. Its keeps within OSM rules, and undoubtedly helps with correct routing.
In the fullness of time, I can only hope that routing engines take account of traffic lights, calming devices, and pedestrian crossings, all of which should steer you away from the city areas. This gives a better representation of actual conditions rather than relying on tagging status.
My main concern with change, and I have said it before, is that once you allow tagging on a persons subjective importance of a certain route/way, then it is always open to invite change. By the very nature of OSM, and we saw it with Kaart, any person or organisation can choose to change status, and who can argue with opinion. So in frustration, it gets reverted. Who is correct ? Edit wars ensue.
We all know how sections of route change characteristics along their length, so once we attempt to define/tag sections, how on earth can we decide which bits are fast and where the slower bits are. And remember, a lot of mapping in Thailand is still done from imagery. One downside of changing status along the length becomes obvious as you zoom in and out on electronic devices - roads suddenly disappear only to show what looks like unconnected bits, until you zoom in further. Hwy numbers are definitive, and not open to argument. The edit wars stop when you employ this method, and the map displays sensibly.
So if I extend my argument for staying with the 2011 decision, and broadly along the lines of Paul’s thinking… where there is a clear case of a, say tertiary 4 lane major road/bypass, needing to go up a status to match its characteristics … then, subject to a short canvass on the forum, we make an exception, and clearly document it on our Wiki. I would like to see the caveat that the whole length of highway is treated as such, and again, not just the bits we think are faster. I guess prime candidates for this in the North are currently the tertiary Chiang Rai-Chiang Saen new road (CHR.1063), and the Hang Dong bypass (CHM.3035) south of Chiang Mai.
Getting “unanimous agreement” on the way forward may not be easy, and I agree that the map has become a bit of a mess in places simply because many of us revere the older mappers and don’t like to change their work. That was until Kaart & Grab taught me that nothing was sacred any more ! However, with something clear on the Wiki that we can refer to, its a step closer, even if in reality, the Wiki can be changed by anyone. I’m happy to go with a consensus from the currently active mappers, and we know who we are. I’ll even change the Wiki if we have a broad agreement, but with Paul’s efforts to nail this problem, I hope it doesn’t fall on stony ground.
Russ.