On Sat, Feb 24, 2018 at 6:00 PM, Lester Caine <les...@lsces.co.uk> wrote: > I think the main problem is that there are well established guidelines for > various areas on mapping data at both country and region level but in may > cases even those rules do not harmonize. We need the several levels of > highway that are currently accurately mapping UK roads, but other areas of > the world do not need that degree of classifications ... so they just don't > use the ones that are not appropriate ...
highway=trunk is currently defined like this in the wiki: "high performance or high importance roads that don't meet the requirement for motorway. In different countries, either performance or importance is used as the defining criterion" So, is it "either" performance "or" importance, or "only one" of those two? It's hard for a local community to agree on which factors count when the definition is vague. What is missing is establishing the >> fundamental purpose << of classification of motorised ways at the global level. Suppose that "performance" is the desirable meaning. That suggests that classification should be done based on physical qualities of the road (leading to fragments of alternating class). If instead "importance" is the desirable meaning, we still need to know what makes the road important: relative or absolute traffic volume? Economics? Planning? Administrative level? Access rights of non-motorised modes? Is it the road's "function" as in "functional classification" [1][2]? Is it the road's suitability for freight [3]? Suppose that "freight" should be an important aspect for the trunk level for any country. That means that trunks must be suitable for truck traffic. That would make the following at least trunk (some might be motorway): - most US highways and interstates (it would be the National Freight Network [4]) - most national AND state highways in Brazil, except those with load restrictions and those that are unpaved and in poor condition (including main routes between several state capitals) - state highways in India (though perhaps not all of them, due to conservation problems - like in Brazil) [1] https://comparativegeometrics.wordpress.com/2013/05/16/how-many-levels-in-a-road-hierarchy/ [2] https://wiki.openstreetmap.org/wiki/User:NE2/classification_FAQ#Why_can.27t_we_use_functional_classification.3F [3] https://en.wikipedia.org/wiki/Trunk_road [4] https://ops.fhwa.dot.gov/freight/infrastructure/nfn/index.htm -- Fernando Trebien +55 (51) 9962-5409 "Nullius in verba." _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
