[Talk-ca] Deleting existing roads...
OK this is really starting to bother me. Roads are scary!!! I tried seeing if I could take two CanVec block and merge them with existing roads. Well I created a mess and ended up deleting the blocks. CanVec data has many little differences... ie: where the nodes are, barriers, location of the roads, the break points between grids, road names... see below (grey CanVec), purple GPS, and orange existing GeoBase. I even had an entire section in a ski resort that the GeoBase had no names (15 ways), where CanVec does and has road barriers too. I have a feeling the GeoBase uploaded to Ontario was something like V5.0 where the CanVec is V6.0 data. Every difference I've found has proven to be more accurate. I have to make like 500-1000 changes per grid if I try to modify existing GeoBase. If I do it the other way around, and replace the GeoBase.. I'm finding I have 20, if any, changes per grid. With 500+ changes my change of making a mistake --like not connecting the roads properly for routing-- increase. CanVec roads line up and connect perfectly with CanVec roads, and other CanVec data. So my question here: How much of a problem is it if I miss tags like "one-way" or move a road that was placed via something other than GPS trails. By replacing the GeoBase/Yahoo roads, then adding and connecting the few that CanVec is missing? Plus adding the few tags that I find. Personally I see more benefit to using CanVec road data. Like the screen shot below, CanVec Road Network, lines up with GeoBase 90% of the time and Yahoo maybe 25%. In every case I've seen CanVec data lines up better with GPS data. Also the CanVec data is going to line up better with other objects in CanVec, like forests, green spaces, and address information. It's just way eaiser to replace the existing roads with CanVec, then modify the CanVec to fit any problems, than the other way around. I just don't want to piss anyone off here. I've done 70 tiles so far and just wanted to get keep going/no go from the community before I continue. ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Deleting existing roads...
I tried seeing if I could take two CanVec block and merge them with existing roads. Well I created a mess and ended up deleting the blocks. Yeah, working with the Canvec data in an already populated area of the OSM map is frustrating to say the least. I've been working on a tile that encompasses my neighborhood and ended up just shelving it for now because there are so many issues merging the two. In the end I've almost ended up just using the Canvec data as a guide to re-align the roads in the OSM data. But it varies, in some areas there is a LOT more detail in Canvec data, while in others the OSM data is better. If you're familiar with the data in the area and are seeing the CanVec to be of higher quality and its meshing up with the GPS traces, then I'd say replacing the existing data is the best bet. I ran into this in rural Manitoba; the existing minor roads (ie farm roads, etc) are marked with yahoo as the source. In rural MB, yahoo is so low resolution you can hardly SEE the roads on the satellite imagery its so low resolution. Its not surprising that canvec is quite off from these roads. In this situation I've just deleted all the Yahoo roads and used the Canvec data. Tyler ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
Re: [Talk-ca] Deleting existing roads...
It's easy enough to check for oneway tags in Josm (Ctrl-F). It may well be there's none in your area. If there're, those can be manually transferred to CanVec data. Another thing to watch out for would be relations representing turn restrictions (sadly, there doesn't seem to be a lot of those so far in Canadian OSM data). Josm should warn about those though. Overall, I agree it's much easier to delete existing Geobase (and only Geobase) if it's inferior. Resulting topological errors with other features not present in Geobase/Canvec, e.g. trails connected to Geobase network but not to newly imported CanVec can be caught with Validator plugin in Josm. On Wed, Jul 14, 2010 at 1:44 PM, G. Michael Carter mi...@carterfamily.cawrote: OK this is really starting to bother me. Roads are scary!!! I tried seeing if I could take two CanVec block and merge them with existing roads. Well I created a mess and ended up deleting the blocks. CanVec data has many little differences... ie: where the nodes are, barriers, location of the roads, the break points between grids, road names... see below (grey CanVec), purple GPS, and orange existing GeoBase. I even had an entire section in a ski resort that the GeoBase had no names (15 ways), where CanVec does and has road barriers too. I have a feeling the GeoBase uploaded to Ontario was something like V5.0 where the CanVec is V6.0 data. Every difference I've found has proven to be more accurate. I have to make like 500-1000 changes per grid if I try to modify existing GeoBase. If I do it the other way around, and replace the GeoBase.. I'm finding I have 20, if any, changes per grid. With 500+ changes my change of making a mistake --like not connecting the roads properly for routing-- increase. CanVec roads line up and connect perfectly with CanVec roads, and other CanVec data. So my question here: How much of a problem is it if I miss tags like one-way or move a road that was placed via something other than GPS trails. By replacing the GeoBase/Yahoo roads, then adding and connecting the few that CanVec is missing? Plus adding the few tags that I find. Personally I see more benefit to using CanVec road data. Like the screen shot below, CanVec Road Network, lines up with GeoBase 90% of the time and Yahoo maybe 25%. In every case I've seen CanVec data lines up better with GPS data. Also the CanVec data is going to line up better with other objects in CanVec, like forests, green spaces, and address information. It's just way eaiser to replace the existing roads with CanVec, then modify the CanVec to fit any problems, than the other way around. I just don't want to piss anyone off here. I've done 70 tiles so far and just wanted to get keep going/no go from the community before I continue. [image: Example #1] ___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca Screenshot-1.png___ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
