Andy Allan wrote:
They can be used by routers to give more accurate descriptions - e.g. since we don't (yet) indicate junction priorities, it can be helpful if you are on a *_link and going onto a * to announce it as "join the main carriageway". If it was e.g. just highway=trunk for both, the router wouldn't know you were on a slip road. Same for when you are approaching an exit, it's a nice hint to the router that you aren't following the main carriageway.
And if you don't have the *_link, then there needs to be a replacement tag to provide that information! Although it should be possible to identify links between different road types, some will still be 'motorway' while others are slip roads and so join or leave. It is more difficult to decided what is going on where the slip roads are between one motorway and another, or motorway and a major trunk road. THESE needs to be specifically identified, and we had this discussion some years ago when the *_link tags were added!
-- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk// Firebird - http://www.firebirdsql.org/index.php _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
