On Fri, 2010-04-30 at 10:47 +1000, Ross Scanlon wrote: > > 1) They're clearly mini roundabouts. I go straight over them on my bike. > > They are concrete circles from Nearmap as far as I can tell. > > > 3) Why an octagon shape? Ugh. At least use the "tidy" function in JOSM > > or Potlatch to make them circles. > > An octagon is the smallest number of nodes to accurately describe a circle. > And they have been tidied using JOSM's circle function.
I just had a quick look and noticed that too. In the small area linked, I counted 9 roundabouts. Turning them into a circle, has given them 18 nodes each. Given that each round-about has 4 entry/exit points, this means for a diamond shape, youre using no extra nodes, for an octagon youre using 36 extra nodes and the current method (18 nodes) has created 126 extra nodes in this area. While I agree that its useful to represent curves and bends properly in the traffic flow, this seems a bit excessive. Youre going from having 9 roundabouts with 36 nodes, to having 9 roundabouts using 162 nodes, for no reason other than so it renders a little bit nicer? One question I do have though, is why put the roundabouts in, and not split up the entry/exit ways? From looking at the nearmap imagery, the entry/exit lanes are divided at each round-about. There also appears to be a lot of footpaths in the area if youve got plenty of time to kill :) David _______________________________________________ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
