New road number format

Just when we have got round to agreeing the format for tertiary roads, being XX.4001 etc.
I come across a new style of road sign/mile marker ~
Located on Sukhothai 3073 Rural rd.

Located on Sukhothai 3176 Rural rd.

Can anyone tell me what they are ? I see some tagged in OSM already.
Do they replace the former Hwy numbers ?

And what format shall we agree on …

or ref=สท.10029
or ref=สท.1 0029

Cheers, Russ.

Hi Russ,

Well, สท is short for Sukhothai, and ถ is the abbreviation for ถนน, road. กม is of course km. No idea why the number is different. Where did the other road numbers come from?

Regards, Tom

I took the 30xx from what was being displayed on my Garmin, just so as I cud give a location later.
I dont recall seeing the blue signs on either of these roads (that doesnt mean they didn’t exist), but I did note that the road 4011, which connects these two 30xx roads, DID have a blue sign.Russ :confused:

As I mentioned in the other thread, this format is the ref for local routes, which are maintained by the local municipality, SAO or PAO. The format should be “ref=สท.ถ1-0029”, according to this registry. (The ถ probably stands for ท้องถิ่น, meaning “local”). I’ve never seen kilometre posts marked with these refs before, but if they’re appearing on a road which was formerly a blue-sign rural road, I guess it means authority over the road was recently transferred to the local government.

In your examples, though, I doubt those roads ever had blue signs at all. The second Garmin ref สท.3176 doesn’t follow the DRR’s numbering format. I think 3073 and 3176 are old ref numbers from when the roads were maintained by the Office of Accelerated Rural Development (รพช.), whose authority was transferred to the DRR in 2002. (Their full refs would probably have been “รพช.สท. 3073” and “รพช.สท.3176”, distinguishing them from the current system.) Some former รพช. roads were given blue signs and new refs. It appears others, including these, were transferred to the local governments. The new refs should replace the older ones.

If you’re willing to upload one of those photos to the Wiki, it could be added to the table on the Thailand page, where there’s already an entry for “Local route” which currently lacks an image.

Thanks for the explanation.
I have cropped the second photo, and made it public so you should be able to grab it and post to the Wiki (as Im not comfortable with that level of editing yet).
The folder link now is
OK, so the new local ref is to replace the older 4 digit one, and the road to be changed to Unclassified ? I’m not sure I totally agree with the logic, but I’ll go with it.
And I guess it wont do any harm to use the oldref=* tag where appropriate.

I ran across some of those markers on my trip to Sokhothai a few weeks ago as well. Thanks for clarifying their use, Paul. I didn’t tag the highway (สท.5064) with the ref but did add two milestones, almost identical in appearance to the ones Russ posted, to OSM with the tag ref=สท.ถ 1-0011.

So, to reiterate, I should retag that highway as unclassified but use the new ref “สท.ถ 1-0011”? You can see this milepost and the highway it’s on in this link:


I saw these in Sukhothai a few weeks ago as well - I think we may all have gone there a few weeks ago.

I captured a few signs as well:

Wow, I like that top one — สท.010 !

No. 2 is similar to the ones Russ and I saw.

No 4 is just an Uttaradit tertiary highway, อต.3016, right?

All the above images are hereby “Public Domain”, feel free to use them on the wiki if it makes sense there.

Thanks Johnny for these pictures we could use to illustrate a tagging guide.

Would you mind uploading them to wikimedia commons? As an original author you should earn the credit for them.

If you don’t want to register there I can upload them.

That way it’s possible to directly use the images in the OSM wiki and wikipedia if desired.
Use [[Image:xxxxx]] in the wiki to link to commons.

We’ll probably also have to decide whether or not to have a space between the ถ and the first digit. The online list I linked to above doesn’t have the space, but some other government documents do.

As for retagging the roads as highway=unclassified, I’m not quite sure how we should approach this. It seems like there is quite some variation in these local roads. (Come to think of it, it’s not really surprising since they cover roads maintained by tambon- as well as province-level governments.) If some local roads are as prominent as blue-sign rural roads, I don’t see why we shouldn’t allow them to be tagged highway=tertiary.

Why make it overly complicated. “classified” means it’s catalogued in some way.
So, tertiary is the lowest level, so any road that has some kind of number should at least be tertiary.

Could everybody agree with that?

I agree with ER on that one … logically, if it has a number, its classified, and therefore, tertiary.

I can agree with that too.

The problem is that the majority of such local roads are not signposted as such. It is likely that most of the streets running through every town and village do have a ref number. But these ones from Sukhothai are the first instance of them being labelled that I’ve seen. (In Nonthaburi, many roads with this type of classification are residential streets.) We could choose to tag such roads as highway=tertiary if they are clearly signposted, but then this would mean our tagging now depends on whether the local authorities decide to put up the signs, and this might vary a lot between places.

It should be noted that highway=unclassified does not mean that the road is literally unclassified. It’s just that the classification of these roads were originally unknown to the public. I think the case here is rather similar to how the highway=unclassified tag originated. According to the Wiki: “The definition of this tag evolved from a scheme to describe the rather populated British countryside… The name derives from the official “U” classification used by UK local councils, but the OSM tag has also been applied to roads which carry other official classifications: the “D” and “C” categories in particular. This has happened because these three official classifications are typically not signposted and so have historically not been available to OSM mappers; nevertheless, the tag is still useful for marking low-importance minor roads.”

I’m not opposed to tagging these roads as tertiary per se, but trying to point out that roads with this type of classification are likely much more common than one might presume.

I added a photo and a short descriptive statement about these local routes to the Wiki today.