Hi,
Mostly I agree with Stephan.
However,
I can give you some examples where this is appropriate.
1: ID 78388648 - last time I rode through here it was labelled ‘1’. It’s an average local road that happens to be a shortcut from h’way 1 to 105. I made it into a tertiary, but I see somebody has now changed that to trunk_link. I don’t think it fits that definition, either and the Thai authorities have since changed the number to 1351. Accordingly I am changing it back to tertiary.
2: Just a little N is Ban Tak. Passing through here a few years ago I saw to my great surprise a milestone ‘1’. (way 77572641) This is a dual carriageway that loops through the little town. It’s hardly a trunk road and one could argue for any classification up from tertiary, so I made it primary. Unfortunately, no Bing images here, so I could only map what I had tracks for, but you can see it clearly in GM and the junctions in Streetview.
3: Going down h’way 1 you come to Nakhon Sawan. The 1 goes through the middle of the town, traffic lights, chaos and all, while the newer 121 goes around the outside as a dual carriageway (and happily is marked as trunk). Since nobody passing through would consider going through the city I vote to downgrade this section to primary.
4: Continuing on S the road splits. AH1 and all traffic for Bkk continue straight on, while the 1 meanders like a river through Chainat and Takhli, where it turns into a little country road, eventually making it to Lopburi. Most of this should be no more than primary: nobody going from A to B will follow this road for any distance and there is little traffic. I would bet that anybody going through the history of these roads will find that the 1 was built first and there were reasons why it meanders. Modern day traffic bypasses this bit, so it’s less significant.
5: In the deep South near Chumphon h’way 4 loops West as a country road, while AH12 and all long-distance traffic follow the 41, which is DC right through to Malaysia. When I drew this a few years back it was primary, but I see most, but not all of it is now trunk, “because it has only 1 digit”. The 41 is a trunk on the map, as it should be.
6: Diagonally between the two runs the 44, which is in the process of being re-classified as we speak, judging from the colour changes when I zoom in and out. This is a big DC and I imagine it carries a lot of the traffic from Bkk to Phuket, Krabi, etc.
7: Hat Yai, same story as 4, it seems.
There are a couple of local roads that have 4-digit numbers right here where I’m staying now. They don’t, however, have any of the standard road signs. That didn’t stop somebody from changing them to tertiary.
I think nobody should re-classify roads s/he has not seen in person, just because of a number. (Unless it’s an obvious beginners error, like primary roads in the back blocks…) We should have some guidelines for classification (based on the numbering scheme, obviously), but allowing for deviations where it is appropriate. Size of the cities or areas connected, size of the road, traffic volume, etc. should all be regarded.
Otherwise (and I am repeating myself here) we will create an administrative map that will end up sending people down the wrong way.
Kind regards,
Peter.