On Mon, 2 Mar 2009 09:50:12 +0100, Guenther Meyer <[email protected]> wrote: > Am Montag 02 März 2009 schrieb [email protected]: >> Hello everyone. >> >> I'm thinking about how to add support for >> proper driving-instructions for roundabouts >> to Traveling Salesman. >> "In 200m enter the roundabout! Then take the second exit!" >> >> There are 2 issues: >> >> 1 How to determine if the roundabout is drawn clock-wise >> or counter-clock-wise. > > is this relevant?
Yes, it is. Not for routing but for the driving-instructions. You need to know the ordering to determine if you count the exits in ascending or descending waynode-order to get the "second" in "Then take the second exit!". ..unless I'm missing someting. > if the routing is implemented properly, the route shouldn't walk into the > wrong direction (roundabouts are oneway). > when the route has been calculated, you just count the number of exits from > > entering until leaving, then you have the number of the needed exit. mmh... can I actually assume all roundabouts to be drawn in the correct direction? This would indeed make my thinking obsolete and this trivial to implement. Marcus _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
