Translating road classification


The OpenTech Thailand community volunteers have started translating the OSM Wiki and iD editor into Thai, but we’re presently stuck with the issue of roads, how should we translate the terms “primary road, secondary road, tertiary road” and “minor roads”?

How about “Thanon primary”, “thanon secondary”, “thanon tertiary”? How much does this mixed language hurt in the context?

It is a technical OSM term, which in probably any country required additional explanation of what a primary, secondary and tertiary road actually is. Or maybe even keep it in the full English term to not hide the complexity of road tagging which is present.
It does not help inexperienced mappers if they tag their favorite residential road as primary/secondary, just because the translation makes it sound suitable.
Road classification requires a bit higher learning curve. You can’t reduce this to a single word translation.

I think Stephan is right in saying iroad classification is more complicated than just translating a single word but if these definitions are presented in the proper context, along with full explanations in Thai, then I see no problem with a designation like thanon primary, or thanon first class, thanon secondary or thanon second class, etc. The definitions will be a bit muddy but that’s the state of OSM and its associated Wiki definitions in Thailand; they’re muddy to the extent that even English-speaking mappers can’t agree on these definitions.

Some further updates

after discussions on Mastodon ( some proposed ideas are:

  • ถนนหลัก ถนนรอง ถนนอันดับสาม
  • ถนนชั้นเอก ถนนชั้นโท ถนนชั้นตรี

Paul012 on twitter ( responded with suggestions to use direct translations of ปฐมภูมิ, ทุติยภูมิ, etc.

As a Thai, I agree with stephankn and AlaskaDave in not translating these terms. It may lead to misunderstandings, for example, ถนนหลัก, ถนนชั้นเอก, ถนนปฐมภูมิ, these three terms would lead mappers to think it is the most important road, but what about trunk?
Mappers should be familiar with these technical OSM terms in order to appropriately determine which class the road should be, rather than relying on Thai words alone.

I would suggest translating the highway=road to something like ถนนไม่ทราบประเภท or ถนนไม่ระบุความสำคัญ, etc. This would encourage inexperienced mappers to tag the road in the safest way possible.

If translating can’t be avoided, the English OSM term should be kept in some way, such as in brackets after words.

For trunk it has been suggested we use “ทางหลวงแผ่นดินสายประธาน” @nitinatsangsit may I request that you take a quick read of and see if any of it makes sense?

If we’re to use English terms alone, it would be completely abstract, and I would like to give Thai speaking mappers at least some sense of hierarchy so that when a they in front of an iD editor, or uses StreetComplete, they can reason a bit:

“Sukhumvit is a level 1 road, this road is roughly the same as compared to Soi Nana which is a Level 3, so this road must be level 1 as well”

Otherwise, if they’re faced with 3-4 seemingly random gibberish choices, “Sukhumvit is a Thanon Primary”, might as well be “Thanon 基本的” which would be indistinguishable from “Thanon 中学” or “Thanon 第三” which I think would lead to a lot more confusion and outrageously bad tagging.

I’ve read it. So, if it’s necessary, I suggest something like:

motorway: ทางด่วน
trunk: ถนนสายประธาน
primary: ถนนสายหลัก
secondary: ถนนสายรอง
tertiary: ถนนสายย่อย
unclassified: ถนนทั่วไป
residential: ถนนชุมชน
pedestrian: ถนนคนเดิน
service: ถนนเข้าสู่สถานที่*
track: ทางเข้าสู่ที่ดิน*
path: ทาง
footway: ทางเดิน
cycleway: ทางจักรยาน

*service road and track can be translated as ถนนบริการ and ทางเกวียน, which seems natural but can lead to misunderstandings in the same way that English can. By the way, if all terms still need to be explained more, this may be a better option.

The term “ทางหลวงแผ่นดิน” is a “National Highway”, which is an official term that should not be used.

Your translations look okay to me since terms don’t sound more confusing than the original ones in English, and they allow non-English speakers to have rough ideas rather than looking at an unknown string.

These are excellent suggestions, thank you

I would probably use “ถนนโครงการ” for service, what do you think?

I prefer ทางเกวียน instead of track.

IMO, ถนนโครงการ sounds a little strange. It sounds like “estate road” or “project road.” It does not appear to be a road that provides access to a specific place. ถนนบริการ might be better.

Without context, I think “ถนนสายย่อย” sounds smaller than “ถนนทั่วไป”. I think “ถนนอันดับสาม” carries the meaning of the English term “tertiary” and implies it’s somehow in the hierarchy.

And IMO, we can use the officicial term “ทางหลวง(สาย)ประธาน” for trunk without conflict. (There can be no other trunk constructed by other organizations than the Department of Highways.) “ทางหลวง” also implies a different class from “ถนน”, avoiding doubt which one is bigger between “ถนนประธาน” and “ถนนหลัก”.

In summary, I propose:

  • trunk = ทางหลวงประธาน
  • tertiary = ถนนอันดับสาม

ถนนโครงการ was derived from ถนนส่วนบุคคล which has a legal definition and cannot be used, I like that ถนนโครงการ implies it’s attached to the location, ถนนบริการ I’m not sure what to make of it. Alternatively, I have the idea for ถนนสาธารนูประโภค but this isn’t quite right either.

Can we do better?

ทางหลวง (สาย) ประธาน sounds good, since ทางหลวง refers to any highway, not only a national highway. Some trunk sections are administered by the DRR and the local administrative organization rather than the DOH. This is acceptable.

Right, word selection would be difficult in this case, but I’m not sure about ถนนอันดับสาม. Where is ถนนอันดับหนึ่ง?, ทางหลวงสายประธาน or ถนนสายหลัก. Maybe call it all in numerical order, ถนนอันดับหนึ่ง–ถนนอันดับสอง–ถนนอันดับสาม, or, ถนนชั้น 1–ถนนชั้น 2–ถนนชั้น 3, or something similar, would be easier.

When we talk about “ถนนโครงการ”, I believe most people do not think of a driveway leading to a building or a road leading to a house parking. It is only suitable for roads in major industrial estates or housing estates, which is not the case for most service roads. (In addition, the housing estate road should be a residential road, not a service road, and, some people may think that ถนนโครงการ means “proposed road”.) “ถนนบริการ” is the exact translation of “service road” in English. For example, the DOH officially call the motorway’s frontage road as ถนนบริการ or ทางบริการ. This may cause some confusion, but it should not be a problem because the English OSM is also confused in this way. If we don’t have a better term, I believe ถนนบริการ is appropriate, as it is aligned with English.

This sounds like a consensus, trunk = ทางหลวงสายประธาน it is

ถนนอันดับหนึ่ง สอง สาม works for me as well

Good point, we can use ถนนบริการ for highway=service

It’s a good choice, but I’m still not sure what words to use. Each has pros and cons.

ถนนอันดับหนึ่ง (สอง สาม) : like an English “1st (2nd, 3rd) order road”. Sounds a little strange, but acceptable if it has to be explained more.
ถนนชั้นหนึ่ง (สอง สาม) : like an English “1st (2nd, 3rd) level road”. Although level is more accurate than order, it may be confused with a building level. By the way, based on the context, this should not be easily confused.
ถนนหลักระดับหนึ่ง (สอง สาม) : like an English “1st (2nd, 3rd) level main road”. I’m not sure “ชั้น” or “ระดับ” is more appropriate, but ชั้น seems more common.
ถนนสายหลัก ถนนสายรอง ถนนสายย่อย : main road, secondary road, minor road. Sounds the most natural, but have a problem with unclassified. Perhaps we can change the unclassified from ถนนทั่วไป to something like ถนนไม่สำคัญ or ถนนพื้นฐาน, etc. to make it sound like a low-important road. (ถนนทั่วไป sounds like a moderately-important road.)

I still can’t decided. Perhaps someone else has a better idea.

How about “ถนนชั้นเอก, ถนนชั้นโท, ถนนชั้นตรี” previously proposed?

IMO, I prefer หนึ่ง สอง สาม over เอก โท ตรี, but either is fine.

So to wrap up, can we settle on:

ทางพิเศษ = motorway
ทางหลวงสายประธาน = trunk
ถนนสายหลัก สายรอง สายย่อย = primary, secondary, tertiary
ถนนบริการ = service
ถนนพื้นฐาน = unclassified
ถนนชุมชน = residential
ถนนคนเดิน = pedestrian
ทาง = path
ทางเดิน = footway
ทางจักรยาน = cycleway
ทางเกวียน = track

*edited to reflect latest changes

This looks fine for me.

I just realised there’s a chance of confusion between the ถนนชั้น terminology and layers which would also be ชั้น, my second choice here would be ถนนสายหลัก ถนนสายรอง ถนนสายย่อย with unclassified as ถนนพื้นฐาน would be intuitive.

Would this also work for everyone?