- I'm not convinced that most trunk roads are dualled. In the UK we tag the "primary route network" as trunk. The majority of that are single carriageway. Oneway is therefore not implied, and must be added as a separate tag. Richard B 01:37, 3 June 2008 (UTC)
- Wouldn't the "primary route network" be highway=primary? As used in the USA, "trunk" should all be dual-carriageway, non-grade-separated roads. That's a fair amount of road needing to be tagged as oneway=yes. Anyway, I don't have strong feelings either way, and a routing system could certainly use different rules for trunk roads in the USA vs. the UK. --Hawke 18:25, 3 June 2008 (UTC)
- No, the "primary route network" is tagged as highway=trunk. These are all A-roads which have green backed road signs and are a mix of dual carriageways and higher-quality single carriageways - or just simply roads connecting important destinations. Non-primary A-roads are tagged highway=primary. These all have white-backed signs, and are usually single carriageways connecting less important destinations - although you can get dual carriageway non-primary A-roads. In sparsely populated areas like the Highlands of Scotland, some primary A-roads are little more than single track roads - but they represent the best route in that area between locally important destinations. The default colours used in the rendered maps on OSM are the same as those shown by the Ordnance Survey maps of the UK. Richard B 20:19, 3 June 2008 (UTC)
- The British tagging of "trunk roads" is different from the rest of the world and this is confusing. In Germany (and the US) one cannot walk on a trunk road. Sometimes - like in Stoke-on-Trent - A-roads even aren't the best way to drive. So I think it would be better to tag A-roads in Britain only as a trunk, when they are like motorroads and in all other cases as primary. --Q un go 12:13, 25 June 2010 (UTC)
Should trunk imply no foot access? In most European countries a trunk is only used for roads which have no pedestrian access (and no bicycle and moped access) (but I'm sure the UK will be different again... :-) ) --Eimai 22:04, 3 June 2008 (UTC)
- I can't speak for the UK, but in the US the only roads where pedestrians are forbidden is on the Interstate highways, which should be tagged as highway=motorway. --Hawke 06:06, 4 June 2008 (UTC)
- In the UK only motorways are off-access for peds, cyclists and learners. You can quite legally walk/cycle down a trunk road in the UK, even the 3 lane dual carriageways - though you might want to get your sanity checked :-), cycling in a rather thin 1m hard strip with HGVs and coaches going past at 60mph doesn't sound fun to me. Jamesb 23:33, 1 July 2008 (UTC)
There might be countries where it doesn't hold true, but I'll soon add that trunk implies surface=paved, unless someone starts a discussion. Please do mention if you know trunk roads that aren't paved. Alv 09:46, 16 July 2009 (UTC)
- So I heard many of the highway=trunk roads south of Sahara are in fact unpaved. Alv 18:12, 22 August 2012 (BST)
Request for a name change
A trunk road in England is one where the Highway Agency maintains it rather than the Local Authority.
For OSM to use the same terminology in a very similar manner is completely stupid as it's causing complete confusion.
I therefore suggest this tag be renamed 'Major Route' or such - either that or simply delete it.
Next name suggestion: 'Good Road'.
Definition of a 'Good Road':
A road where a vehicle of its type can safely maintain its speed to the National Limit for that type of vehicle. This is achieved by:
1. The road not being locally speed restricted.
2. The road being wide enough.
3. The road being straight enough.
4. The road being smooth enough.
5. The road being flat enough
- I partly agree but mostly disagree with you. Firstly there are several countries apart from United Kingdom who adopt the term trunk (or translation of it). In these countries this tag make perfect sense. Secondly there might be strange to have two highway classifications higher than primary, motorway is somewhat self-explanatory, but given transit regulations in several countries is can make sense to have another higher than primary classification. If we are to make a tagging scheme with terms fitting any country than an in-depth study of transit regulations and highway classification worldwide is necessary. I prefere to stick to the current system, and rather add additional tags to further distinguish the classes, such as the much used in spain motorroad=*, or as done in Brazil with defining a tagging scheme that the community have agreed on. The use of highway=trunk should imply a certain set of rules (access restrictions, maxspeed, surface quality, etc) on a national basis in a form that can be adapted by routing engines as a form of default values to improve routing. Each highway classification would need such definition individually as highway=trunk would be defined differently in England, Germany, Norway, US of A, Brazil and other in the same way as highway=motorway, highway=primary, etc. --Skippern (talk) 10:40, 5 December 2014 (UTC)
Trunk vs motorroad
- Corrected with https://wiki.openstreetmap.org/w/index.php?title=Tag:highway%3Dtrunk&oldid=1183475 Please delete this section after reading --Hb 14:36, 26 May 2015 (UTC)
change "high performance" to "high importance"
I consider "Use highway=trunk for high performance roads that don't meet the requirement for motorway" - in some regions critical roads are not high performance. For example in Africa some important roads connecting cities are correctly tagged as highway=trunk - and these roads are unpaved. Mateusz Konieczny (talk) 12:04, 17 July 2016 (UTC)