[OSM-dev] Algorithm help

[Tom Evans]

> Consider a way from 0°, -189.999° to 0°, 180°. that is, in our current 
> datamodel, a way that's roughly 40,000 km long.

No.  In the datamodel, it's just a way between two nodes.  
The nodes are defined in lat, lon, effectively in spherical co-ordinates, 
hence them being angles.  (ignoring not-quite-spherical deformities for now)

If a tool says the length is 40,000km, the tool is incorrect.
But the datamodel doesn't specify the length, just a sequence of nodes.

Tom

(assuming you mean -179.99, not -189.99.  That would be different)