On Tue, Aug 13, 2019 at 7:35 AM Paul Allen <pla16...@gmail.com> wrote: > Hard agree. Even though it's starting to look like I live in the only country > in the world with a national classification system that is logical and > internally consistent (and even we have a few rare exceptional cases). :)
The US certainly doesn't, because of the way we practice federalism. All fifty states have their own classification systems, and the classifications have more to do with how funding is doled out than the actual importance or traffic volume of the road. It is more political than technical. (Thanks to Martijn van Exel for pointing that out in last night's Zoom call!) Back in the days when you would grab a road map at a gas station in the US, the map-makers used their own hierarchy which was usually based on the attributes, "toll charged", "grade separated", "number of lands" and "surface". They typically aggregated these into about half a dozen different renderings, and had a legend on the map explaining the symbology used. I suspect that as routers get more sophisticated, the classification will become progressively less important, because attributes such as these will be taken into account more. Until then, we'll we'll always have some arguments, at every level of the hierarchy. Recent arguments: "Is a six-lane dual-carriageway with a 120 km/h speed limit a motorway if it's hgv-no?" "Is a road built to full motorway standards actually a motorway if its service is suburban rather than interurban?" "Can a surface street that parallels a motorway ever be a trunk, or even primary?" "Can there be tertiary roads in a state that doesn't have county highways?" "Is there actually a difference between 'residential' and 'unclassified' in rural areas?" "Is the last segment of a motorway actually a motorway when it ends at a grade crossing? (What if the grade crossing is tens of km from the last elevated crossing?)" Of such questions are edit wars made, and edit wars make the classification even less useful. Out in the boonies, I've encountered roads where other mappers have argued to me that the classification ought to be "tertiary", "unclassified", "residential", "service" or "track" - because different attributes of the (admittedly poor) road were important to different mappers. (Numbered county highway; the principal route, at least in summer, between two villages; non-hard-surfaced; a low-clearance automobile would have a bad day in inclement weather and a road bike would have a bad time any time; there are at least a few homesteads along it; and the primary reason for travelling in that particular area at all is forestry.) Alas, we can't do what Google Maps does, and aggregate the private information of everyone carrying a cell phone to measure current traffic speeds. That appears to be how Google's router makes its decisions. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
