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Does every island have a trunk road (provided that there are humans on the island and they move about on land)? If "trunk" is defined by function and not state of development (i.e. pavement, on-ramps, number of lanes, etc.), then the answer is yes.

For instance, take the Philippines, the country I live in. Every major island has at least one road which usually circles the island, though sometimes it doesn't quite make it around. All the other roads branch off of that road, like branches off a tree trunk. Often all roads lead to a major city and port (see Panay and Iloilo City). Often that one main trunk road is called "The National Highway" or simply "The Highway" (national in this sense meaning owned and maintained by the National Government).

The mapping conventions of the Philippines suggest that the answer is yes when it says trunks roads are "National Roads (for example the McArthur Highway and The National Highway down Laguna de Bay)..." and that primary roads are "Other main roads in cities (e.g. Pasay Road, Buendia) and between towns." If primary roads are "other roads", then if there is only one road that one road must be a trunk. And if that one road happens to be a dirt path then that dirt path is by this definition a trunk, and in the same category as the biggest, widest, most advanced motorway.

Do I get the trunk concept right?

asked 02 Oct '14, 13:23

Iloilo%20Wanderer's gravatar image

Iloilo Wanderer
accept rate: 0%

edited 02 Oct '14, 13:24


What about asking this maybe more local topic on the OSM Philippines mailinglist?

or the OSM Tagging mailinglist?

(02 Oct '14, 14:29) stephan75

Keep in mind that highway classes can and will have different meanings in different countries. If the road in question matches the trunk definition of the Philippine mapping conventions then map it as a trunk road :)

(02 Oct '14, 14:49) scai ♦

I think the answer is no, take e.g. the Waddeneilanden in The Netherlands. There are small villages, but no trunk roads (according to the Dutch definition)

(02 Oct '14, 17:14) escada

Thanks for all the comments. I agree that such questions could probably be better handled specifically by country but not exclusively for two reasons. First, many countries are not isolated with distinct road systems but rather part of larger road networks (e.g. Belgium and the E.U.). Second is the opposite case -- many countries are not one single network but are rather multiple network. Therefore rules that apply to one part of the country do not necessarily apply to another. The Philippines is an example. Most of the Philippine conventions are not based upon mega Manila and may not easily translate to the road network of Panay or Leyte. Therefore my general question. I will check out the OSM Tagging mail list to see what they say.

The general rule seems to be to look for the trunk of that particular, distinct road network. Waddeneilanden is not a distinct road network but part of the Netherlands whereas Panay and its smaller subsidary islands (Boracay, Guimaras, Islas Gigantes, etec.) has no significant connection to any road network. Therefore Panay will have a trunk road that might look very different from other trunk roads in other networks.

(19 May '15, 05:06) Iloilo Wanderer

I tend to agree that in most cases these should be trunk, considering the Philippines mapping scheme. However, I don't think a "highway" which is not accesible to four wheel vehicles (you mentioned a 'path') should ever be tagge as trunk. This should be a type of path. That said, I would personally rather not see local tagging schemes where unpaved roads are considered trunk. Even the Highway Tag Africa scheme keeps those in primary. Also, don't forget to tag extra information, such as surface, width etc. when the classification does not imply certain road quality standards.

(19 May '15, 10:32) joost schouppe

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question asked: 02 Oct '14, 13:23

question was seen: 8,985 times

last updated: 19 May '15, 11:00

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum