"Manfred Brenneisen" <Manfred.Brenneisen@gmx.net> writes:
Thinking about maxspeed:practical, which can be used to initialize maxspeed in some cases, I thought about rural areas, which do not have any maxspeed, or maxspeed:practical information included in OSM data:
I think we do need tags for maximum speed that tends to be reasoable typical speed one can go
The new curviness() function (useful for ways).
Such a function could e.g. return the sum of direction change at every point, divided by the way's length.
This could give an estimation for the maximum practical speed.
This could be useful to drop the speed absent tags, but I would worry that it would be very sensitive to how well the road is represented. As a completely alternative approach, one could process tracks to obtain maxspeed:typical values for ways. A related concern is if some ways (the more commmonly-used ones) are tagged, then the untagged, even scarier roads will be preferred by routing.