I’ve only joined OSM recently and I have finding help with OSM features on the website, thought I’d ask before messing things up.
I understand that it is not possible, unlike Wikimapia, to use GoogleMaps aerial view to trace from, some copyright issue of some kind. In which case, what can I use in the custom field to see where I’m tracing. Funny (not) tracing a house without seeing its outline. The Yahoo (why Yahoo?) option does not show and where ever I browse to ‘data is not available’. I understand one can use other mapping overlays to trace from but my preference is from aerial shots as it simply shows what IS there.
In areas of interests I have roads, rivers and I would like to add features: bridges, tunnels not yet on OSM. How do I select a portion of a spline to edit a single section between vertices (OSM calls them nodes?) to change a single section of road to a bridge for example?
If a spline has too many vertices, how do I delete some to simplify the tracing or redo a whole section of road/railway?
Nearly all? So what questions do you have left? OSM doesn’t use Googlemaps data because it is all copyrighted. For OSM to be open source it must use data that is open source. Ordnance Survey Opendata is now open source, so you can use that to trace over. It is no substitute for going to the location and mapping it yourself, but it is a good starting point for getting useful data in.
Yes, lots more aerial imagery available in Potlatch 2. BUT, please dont rely on aerial imagery: much of the Bing imagery is sourced from GetMapping and is upto 10 years old: I’ve recently been working on Oakham and it does not show the Oakham ringroad (mostly opened by 2007). No aerial imagery shows the new A52/A46 roundabout at Bingham (http://osm.org/go/eu8w9gsq), nor do most commercial on-line map providers, but OSM DOES. This is because someone has gone out and surveyed it.
To add bridges, tunnels, changes in speed-limit etc., cut the way at appropriate points and add the additional tags to the new section of the way. Don’t worry about a way being chopped into lots of little pieces: it’s just the way OSM works.
