I'll try again with this...
...third time lucky ? ---------- Forwarded message ---------- From: Pmailkeey . <pmailk...@googlemail.com> Date: 1 January 2015 at 23:36 Subject: What are you mapping and have you fully though through the implications of bad data ? To: talk-gb <Talk-GB@openstreetmap.org> Hi all, OSM is a great idea and I'm having a lot of fun filling in data locally. It's annoying to add things to the database and find them not appearing on a general map - is there not an 'all data map' ? Sidewalks - which I've used to mark kerbs as they should be marked. This leads to why I left OSM years ago: The marking of roads by a single line - an easy and cheap solution. I'd planned to map by real data such that a road (carriageway) would be defined by the position of its boundaries (be they kerbs, hedges or walls etc.) Whose map are we drawing - the real one or some random person's interpretation of a 'map' ? It seems to be a bit of both where 'road classifications' are being randomly invented for the purpose of confusion. It's quite obvious it's not clear what is meant by each road classification and the specific names doesn't help. 'Trunk road' is a DfT term and has a specific meaning. It's a terrible practice to use the same terminology for your own definition of what one is - and it seems OSMers aren't exactly clear on what one is. That name needs changing. As for the other classifications, they're just meaningless names and have little use for a map user. The pretty colours maybe aid in road selection by accident. Should a map be the judge ? should the map just show what's really there on the ground and leave the map user to decide which is the best route and roads to use ? The answer to that is clearly yes and no ! It is wrong for mappers to prejudge a route and colour it accordingly, however it is really hand for the user to see routes more prominent on the map to guide the user along more favourable routes. There is a classification for motorway - because it's a distinctive route and has a different set of legislation. Dual carriageways also have a different set of legislation - so they too should have their own symbols. As for the rest of the roads, they shouldn't be judged or classified on the ad-hoc labelling that has gone before. As is recognised, an A road can have anywhere between one and six lanes inclusive which makes it a completely useless guide to the type of road it is and the suitability of it for each user type. If the map is to show roads by classification, then the classification needs to be based on reality and not historical classifications. I think all roads should be classified by 'speed' and speed alone (possibly!). I'll suggest some universal names and detail how to calculate their speed for the purposes of classification. Then perhaps we can have a heated debate about the whole topic! Motorway Excellent (road) Good Average poor bad. There, universal in English globally. Average to be locally 'determined' and the others based on that determination. In the UK, I'd consider: Excellent (Minimum 2 wide lanes; no steep gradients or tight curves and lit where desirable. Basically two on-coming 44T trucks would be able to maintain national speed limit at all points they may pass each other (with the exception of significant junctions/roundabouts) Good (Minimum 2 wide lanes but with cause to reduce speed here and there for whatever reason e.g. traffic lights, tight curves, gradients, narrowings, built-up areas etc.) local speed limits. No traffic type, width, weight, length or height restrictions Average (2 lanes minimum - opposing 44T trucks need to negotiate their passage but not stop, more curves, gradients, traffic lights and low speed limits (30mph) here and there) Poor (one wide lane minimum - enough for 2 cars to pass each other with negotiation and reduced speed. OK for medium-sized trucks but not 38-44T trucks Expect loads of hassle/stops in wider sections to let cars pass; a need to use the wrong side of the road both before and after a bend. Steep gradients needing low gears. No chance of getting up to national speed limit. Bad (one narrow lane, cars need to stop and pull over to let the other opposing one pass. Unsuitable for trucks other than for access. Track - effectively 'off-road' not tarmacked, rough, possibly soft etc. etc. What are the legal implications for OSM(F) on a map user having an accident as they've used what OSM shows as a trunk road but isn't ? Not only are there legal implications but also OSM's reputation as being a trustworthy map It is correct to label roads with *refs* (e.g. A1) but incorrect to rate (classify) the road based on someone else's labelling scheme. I have the same issues with footpaths. I'm using 'footpath' to be wheelchair-friendly and 'path' to be unfriendly - crossing fields or steps en-route. Make maps available for different transport users and services map (mailboxes, hydrants, underground services overhead cables) - rather than the current random offerings. Allow the user to choose a date window (2000-current, for instance.) Maps need to be plotted in 4 dimensions: X, Y, Z and T and I don't know why you've allowed OHM to start up with historical info. All map info is historic - some of it was valid yesterday! All data needs a start and end date and that means every tag as sometimes these can change ! I suspect it'd be better for any responses to bits of this would be better placed in their own thread ! For my next topics, I will do ! -- Mike. @millomweb <https://sites.google.com/site/millomweb/index/introduction> - For all your info on Millom and South Copeland via *the area's premier website - * *currently unavailable due to ongoing harassment of me, my family, property & pets* T&Cs <https://sites.google.com/site/pmailkeey/e-mail> -- Mike. @millomweb <https://sites.google.com/site/millomweb/index/introduction> - For all your info on Millom and South Copeland via *the area's premier website - * *currently unavailable due to ongoing harassment of me, my family, property & pets* T&Cs <https://sites.google.com/site/pmailkeey/e-mail>
_______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
