On 7/3/20 8:18 am, Paul Norman via Tagging wrote:
On 2020-03-06 9:22 a.m., Peter Elderson wrote:
That sounds even more odd to me... what if it doesn't match? Do we
have authoritative gpx-es for routers?
No. There is no one true route between two points, so there can't be
an authoritative router.
Why routing is a good idea.
Let us say a route uses 4 ways in sequence.
If those ways are sequentially inside the route then things are fine.
It breaks when
a mapper enters a turn restriction, breaking one of the ways
a mapper enters some road works that close a section of one of the ways
a mapper enters some speed limits that change alone one of the ways
All of these break the route.
If the route is entered as nodes on the intersection of each of the 4
ways then any of the above mapper changes will not brake the route.
The routing engine may not pick the actual replacement route .. but it
should be a reasonable approximation.
----------------------------------------------------------------------------
The above could be the best way forward - it relies on the nodes used
connecting continuous ways together thus leaving the routing engine
little work to do.
When (not if) that rule is broken then it indicates that the route needs
to be checked, but in the mean time the routing engine will maintain the
route in a usable fashion.
_______________________________________________
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging
