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
Discussion
Comment from wieland on 8 March 2010 at 07:20
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.
Comment from Zartbitter on 8 March 2010 at 08:02
There's no problem extending the roads on connections. This is widely used. Here is one example:
osm.org/go/0HtF_vpbN--
Comment from davespod on 8 March 2010 at 12:55
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.
Comment from pavithrans on 9 March 2010 at 00:31
@wieland: There are 3 places where U turn is possible. I think its better to mark them .
Comment from pavithrans on 9 March 2010 at 00:31
@ Zartbitter: Thank you that was helpful .
Comment from wieland on 9 March 2010 at 06:27
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.
Comment from pavithrans on 9 March 2010 at 06:47
@davespod Yes the roads must join for navigation . I think making it 2 roads in 2 directions would solve my problem.