OpenStreetMap
These are some dificulties while mapping 'fat' roads and their connections :(
In India while driving we drive on 'left'. I was collecting GPS traces on some big roads.
This road now appears as 2 lines as forward direction line will be on left while reverse direction on the same will appear on right.
I could mark the road as average of these 2 lines. but how do I mark the connections ? For connections i need to extend the actual road which means drawing a non existing road . I also need some practice marking junctions and creating round abouts
讨论
wieland 于 2010年03月 8日 07:20 的评论
Why don't you map it as two oneway roads?
If it is not possible to u-turn at any point, this seems to me the best.
Zartbitter 于 2010年03月 8日 08:02 的评论
There's no problem extending the roads on connections. This is widely used. Here is one example:
osm.org/go/0HtF_vpbN--
davespod 于 2010年03月 8日 12:55 的评论
Generally mappers only show two one-way roads where there is physical separation between traffic in each direction. However, if I understand you right, you are concerned that a side-road joining the wide road will be represented by a line going right to the centre line of the wide road? This is quite acceptable. In fact, it is very important they do meet in a junction, if the data is to be used for navigation.
When using lines to represent roads, we are really just mapping the centre lines of the roads and their connections. There has been some debate from time to time about whether micro-mappers should map roads as areas (in addition to mapping the centre lines), which would solve the problem of how it rendered on a large-scale map, but I don't think this is common at the moment.
pavithrans 于 2010年03月 9日 00:31 的评论
@wieland: There are 3 places where U turn is possible. I think its better to mark them .
pavithrans 于 2010年03月 9日 00:31 的评论
@ Zartbitter: Thank you that was helpful .
wieland 于 2010年03月 9日 06:27 的评论
3 places to U turn means mark them.
Sometimes it is only possible to U turn in one direction e.g. here:
osm.org/?lat=49.992257&lon=8.649385&zoom=18&layers=B000FTF
Comming from south or from the gas station you can turn. But not comming from north, than you have to go to the next side street.
pavithrans 于 2010年03月 9日 06:47 的评论
@davespod Yes the roads must join for navigation . I think making it 2 roads in 2 directions would solve my problem.