Convention for transliteration of Thai street names


I just returned to Thailand after a four month visit to Alaska and found a whole bunch of newly installed street signs in my neighborhood of Ban Chang Kham. Many of them have alphabetic one-character suffixes that, as I see it, are similar to our practice in the Englisg speaking world of naming things with a trailing A, B, or C to differentiate them. The question is how should I translate a name like the following for the name:en tag?

บ้านช้างคำ ซอย 4ด

Should it be Ban Chang Kham Soi 4 Dek, Ban Chang Kham Soi 4 Daw, or maybe Ban Chang Kham Soi 4 Daw-Dek?

My girlfriend thinks Thais would say the suffix “ด” the same way they would say it if they were reciting the alphabet, as in daw-dek.

What should we do?



I’m pretty sure in general speech it’d be said as Soi See Daw (which according to the Royal Institute transcription system would be Soi Si Do). The consonant names (chicken, egg, buffalo, etc.) aren’t used in official contexts either. However, we’d run into problems long before reaching ด, as it’s impossible to distinguish ข and ค using the Latin script, unless diacritics are used.

I saw a place that had this, but the sign was in both Thai and Latin letters.

4ก was translated to 4A
4ข was translated to 4B

I am not saying this is the correct way, I just wanted to present this option as well.

Thanks for the quick replies,

Based on what Paul said, and keeping in mind that the transliteration is not primarily for Thais but English speaking users, maybe Johnny’s idea is best:

4ก was translated to 4A
4ข was translated to 4B

I’ll wait to see if anyone else has a different or better idea before proceeding. It’s always difficult to transliterate Thai to English and vice-versa. This problem has popped up before, back when I first started mapping streets in Chang Phuak district. Now, looking back on those, I see both variations are present on several small sois running off Chang Phuak Soi 4, probably because I named some and other OSMers the others. Either way, we need to find one method we can all agree upon and then stick to it in the future.

I believe I have seen those A,B,C extensions somewhere on signs as well.
Chang Phuak Soi 4 has plenty of those sub-sois. Jo had recommended to tag them a,b,c, and so on, as this is what is also done in Thai. If we want to make them also find-able by the search we could add an RTGS alt_name:en as well, as mentioned by Paul.


Some additional considerations have changed my thinking on this. In the interest of staying with a pronunciation that would work for both Thai and English speakers I think it would be best to avoid using English suffix letters, except in an alt_name:en tag.

Let me explain. If you’re a Thai person, the name บ้านซางคำ ซอย 4ด might be spoken as Ban Chang Kham Soi Sii daw-dek or possibly as Ban Chang Kham Soi Sii daw. If you’re an English speaker asking for directions of a Thai man, you will certainly need to use one of those two forms if you want him to understand you. You will get only blank stares if you ask about a Ban Chang Kham Soi Sii D. The only time when such a tag would make sense is if there are only English speaking people in your world. The D suffix doesn’t appear on street signs and will never be spoken, except in our little OSM community. It’s purely an invention designed to make a Thai name appear more English-like.

I respectfully suggest that we use names in the format “Ban Chang Kham Soi 4 Daw” for the name:en tag and “Ban Chang Kham Soi 4D” in an alt_name:en tag

Opinions? Suggestions?

It appears that nobody objects to my proposed scheme so I’ll start using it. In my scheme the street name บ้านช้างคำ ซอย 4ด would get a name:en tag of Ban Chang Kham Soi 4 Daw-Dek.

On a related topic, many of these new street names include the muban in the name. My thought is to use the muban number in a different tag, for example, is_in:hamlet=หมู่ 8, and avoid using it in the name tag. This shortens the name and makes it more like what we see in most parts of the kingdom. However, it does add the potential for confusion because two nearby sois could have identical names but be in different mubans.

Opinions? Suggestions?

I think it depends. How are the muban numbers written on the signs? If it’s as large as the rest of the name then it should probably be regarded as part of the name, IMO.

As for the alphabetic naming, ultimately they’ll also have to be decided case-by-case. For your muban, which seems to use them for a lot of sois (seeing as they run up to ด, which is the 20th consonant) I agree that transcribing the Thai alphabet names is preferable. In other cases which don’t go further than ก, ข, ค, ง and จ, matching them to A, B, C, D and E might be better. That is, of course, if there is nothing on the signs already.

The muban number is typically the same font and size as the main name. I will leave them as is and include the muban as part of the name. It makes for a very “bulky” name but if that’s the proper name for those sois, so be it.

I’m okay with naming the suffixed names on a case-by-case basis. But it does seem to me that using A,B,C for some and gaw-gai, daw-dek, etc., for others will lead to confusion. Shouldn’t we stick to one convention or the other?

I oppose it. First Jo also suggested to use latin alphabet a,b,c for those sub-sois when asked on how to express with latin chars. Second this is also how official signs are done at least in Chiang Mai.

For making it findable you could use your direct transliteration in alt_name:en.

For streets I can’t remember having it seen more than a-d. So I suggest to use this. And for communication with taxi drivers/etc I recommend to use a printed map/app with bilingual labeling :wink:


At first I was going to disagree with you based on the sign that used daw-dek, the 20th consonant, which corresponds to a “T” in English but I went back to check that sign again yesterday and found I had made a mistake. It is not daw-dek but kaw-kwai, the fourth Thai character. Unfortunately, the text boxes in my various programs use a small font and my original photo was not clear enough to make the distinction between those two very similar characters. My mistake. A neighboring soi has the naw-nuu character suffix corresponding to “G”. I don’t think such suffixes extend much further numerically than that one so the simple A, B, C, D notation scheme will work. I’m assuming that were the authorities to desire a series of suffixed street names extending beyond 7 they might use a more normal numerical scheme, but who knows?

As you can see, there is no English on the signs in Ban Chang Kham (my neighborhood). These nice new signs are to be found in several nearby bans but none include an English version. The sample image you show in your post is, in my experience, quite unusual in Chiang Mai.

At any rate, I renamed the streets near me to use the A B C D suffix scheme. There are a few others that might need changing but I’ll catch them later on.



After I wrote that reply I checked an area I had worked on a couple of years ago in Chang Phuak that has several small sois off Chang Phuak Soi 4. I tagged some and you, Stephan, tagged some others. These sois extend to ถนน ช้างเผือก ซอย4ฉ, which brings up a further question concerning the scheme we’re discussing. When assigning numerical correspondences does one count the two obsolete characters “ฃ” and “ฅ”? I forgot about this when editing those new tags, using a “D” for ค kaw-kwai, but I note that in Chang Phuak you assigned a “C” suffix to a soi having the kaw-kwai suffix, ถนน ช้างเผือก ซอย4ค (name:en=Chang Phuak Soi 4c).

I reckon we will need a cheat sheet of correspondences in order to use this scheme without errors LOL!

I’m assuming we should ignore both obsolete characters. But what if someone locates some older signs somewhere in the kingdom that use the obsolete chacaters? Shouldn’t our scheme allow for such an event?

With ด (do dek) out of the way I think it’s an easy choice to settle on the ABC scheme. It’s not just the obsolete characters ฃ and ฅ that are usually skipped. ฆ (kho rakhang), which sounds the same as ค, also is. It’s pretty standard to use ก ข ค ง จ ฉ ช as the default alphabetical list headers, though what follows after that is probably unclear.

Actually, I looked a bit more and a brief Google search revealed this Army regulation on list numbering in official documents. It specifies exactly 26 Thai consonants to use, so that gives exact correspondence with the Latin alphabet. They are:

ก A
ข B
ค C
ง D
จ E
ฉ F
ช G
ซ H
ด I
ต J
ถ K
ท L
น M
บ N
ป O
ผ P
ฝ Q
พ R
ฟ S
ม T
ย U
ร V
ว W
ส X
อ Y
ฮ Z

I’m not sure if this stems from a general government guideline, but even if it did I doubt that in practice the local government employees who name the streets would always be aware of such regulations. So we could use the above as a general rule, but it’s possible that some signs won’t follow them nicely anyway.


You probably meant cho ching (ฉ), which looks quite like no nu but with a “roof”.

Apparently it is not the case that the above consonant list is used by the government. There are plenty of laws that bear the bullet headings ก ข ค ง จ ฉ ช ซ ฌ ญ ฎ ฏ ฐ…, which is pretty inconsistent and, IMO, quite stupid, since why would they skip ฆ but not ฌ, as its sound is also redundant with ช? But such is the way of things.

Anyway, ฆ does seem to be universally skipped, so we shouldn’t have any problems up to the eighth consonant.

Actually, seeing the picture, I’d probably leave the muban name out of the name tag in this case. It does seem that the main message of the sign is actually ซอย 4ค, with บ.ช้างค้ำ ม.11 something of a subtitle, providing further information.