Hi, I am a proponent of using the Highway Functional Classification System, which Alan has described below and is on the wiki.... http://wiki.openstreetmap.org/wiki/Highway_Functional_Classification_System
I've classified roads in Clarke County, Georgia and the surrounding counties using the HFC System with what I think are good results. http://osm.org/go/ZSCaTrq Kevin On 3/4/2010 6:12 PM, Alan Mintz wrote: > At 2010-03-04 09:38, McGuire, Matthew wrote: > >> ... >> A road's Observed Character is what kind of road it appears to be to a >> person on the road. For general purpose maps, using observed character to >> classify the roads intends to match a person expectations to what they see >> on the ground. Character is highly correlated with function, but is not >> the same. >> >> I think Observed Character is what OSM is trying to achieve with the >> highway tag. I think this because the OSM tag descriptions for highways >> have photos and describe how the road looks, and you cannot determine >> system or function from a photograph. I also think it is what the Census >> Feature Class Code definitions describe. >> > I disagree. Even if this is what was intended, it's certainly less useful > than the others. When I zoom out a certain amount, what I want to see is > the local (aka residential in OSM) roads disappear. Further out still, I > want to see the tertiary roads disappear, etc. This is what's useful when > trying to map a route through an unknown area - you want to stick to the > main roads that get you there with better road conditions, fewer > intersections, etc. > > As an example, in this area: > http://www.openstreetmap.org/?lat=34.426&lon=-117.664&zoom=11&layers=B000FTF > , 2-land paved roads are few and far between, making them important > tertiary or secondary connections. A road with the same characteristics in > the city would be unclassified, as there are much better roads. It's all > relative to the area, which is why I don't think it's reasonable to > classify by any objective characteristics - you have to know or survey the > area in order to know how to classify them. Perhaps some people with a lot > of experience may be able to do this from satellite imagery. > > I believe this closely matches what I see in transportation sections of a > city's general plan. I think it's useful to use these as guidelines when > classifying roads. Many cities/counties of any reasonable size make these > available on their website. They usually have: > > - freeway, expressway, etc. = OSM motorway or trunk > - primary arterial = OSM primary > - secondary arterial = OSM secondary > - minor arterial and/or collector = OSM tertiary > - local = OSM residential or unclassified > > -- > Alan Mintz<[email protected]> > > > _______________________________________________ > Talk-us mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-us > > > _______________________________________________ Talk-us mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-us
