Hagen Riedel wrote: > I think it is very important to update the following site: > http://wiki.openstreetmap.org/index.php/Editing_Standards_and_Conventions. > > For myself as a newbie it is important to see some examples and have some > guidelines. Even more it does not make a good impression if new users are > linked to an out-of-date information site. > > In my opinion the page should answer the following questions: > Can I already use proposed features? > You can use any tag you want to - but only tags used by more people will be useful. Consider voting for the proposed features you want to use - that way they become "official" faster.
Instead of just making up a new tag - propose it. anyone can propose new tags. > How accurate one should map? How many points roundabouts A roundabout needs at least one point per connected road - and at the very least three. Many roundabouts are made with 4 points. Feel free to use more - *if* your pretty roundabout is accurate. I.e. don't make a 12-point roundabout if all you have is 2 gps points at the location. You can get accurate roundabouts by going all around in the outermost lane with a good gps. Don't do this when there is heavy traffic though. You can get accurate connections by driving in and out each connected road. Sometimes the connecting roads split into an Y-shape as they connect. If you map such detail, use the oneway tag appropriately so navigation software won't think there are twice as many exits. How much work you put into this is up to you. The 4-point roundabouts are sufficient for navigation purposes. Elaborately mapped roundabouts with 12-16 points and Y-shaped connections look slightly better when you zoom in a lot. Josm has a tool for turning a set of points into a perfect circle. After using it, reposition the roundabout by dragging, as it tend to get offset. Remember that roundabouts are directional - don't make them the wrong way around. > and slopes should have at least/most? Is it best to use as few as possible > points with straight ways? If the road isn't straight - don't make it straight. Be aware that gps has limited precision. So don't bother forcing the road to follow your gps track withing 0.5m precision. The data isn't that good anyway. Still, a road with sharp turns may need points with 2s distance or so in the turns. You can get away with a lot less in wide turns and almost straight sections. To put it simple, the straight pieces you make shouldn't be further away from the stripe of gps points than the gps precision. And it is usually a good idea to do better than that too. GPS may be 10-20m off, but that error is almost the same for many points. The shape of the road (points relative to each other) has higher precision, and it is nice to preserve that. If the road consist of a series of slight curves (road in the hills/mountains) then it is useful if each curve actually is on the map. People can then use instructions like "third left curve after the intersection." > Is it recommended to use overlapping ways (car, tram, bike)? > Usually not - josm will even warn you about it because it is usually a mapping error. car+bike: make a car road, and add cycleway=lane (if there are bike lanes) or bicycle=yes. A cycleway next to the main road can be mapped separately. The tramline may overlap - if cars really drive in the tram lane. If not, perhaps it is a dual carriageway with a tramline in-between? > How to make nodes aligned in pairs (separated highway)? > Drive down both ways - then your gps will log two lines. Make both roads. Set down the nodes in pairs, that way the road-road distance will be constant even in turns. Like this: *-------*-------* *-------*-------* Not: *-------*-------* ----*------*--------* > How areas should be tagged (adjacent or with space between)? Mark big > buildings or just the outline of residential areas? How to tag towns and its > suburbs? Is it sometimes good additionally to add a point, e.g. with parking > areas? > Add anything that you _can_ add. My gps isn't accurate enough for small/medium buildings. Large buildings are often tall too - creating other problems if you go too near with a gps. Of course there are other tricks, like satellite images or measuring distance between walls and roads. Also, bear in mind that you don't _have_ to map everything you _can_ map. Getting the roads, cycleways and parking lots are probably more useful than the buildings. Buildings are a bonus - I can plan my shopping trip even if all I see is the road, the parking lot and a shop node. I will assume that there is a building there. :-) Many questions can be answered by looking at the work of others. Download pieces that are very well mapped and have a look! Note that some countries have different standards - preferably look at your own country. Helge Hafting _______________________________________________ newbies mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/newbies
