Should the western half of these segments be elevation -1 as the M4 does actually go underground at this point and there are roads on the ground above?
It doesn’t really matter. Although elevations are currently being rendered on the Livemap, HQ said this was a mistake and wasn’t supposed to have been released - although they seem to have made no effort to roll it back.
They also told us at the UK Meetup “not to worry too much about elevations”. By all means correct them if you want to, but don’t put any great effort into it at the moment.
Anyway, it doesn’t hurt, so I’ve buried that section of the M4 for you. :mrgreen:
Waze won’t learn speeds of segments with negative elevation, though they are working to change that model.
and yet the wiki says:
“Road elevation
The Road Elevation should be changed where one road passes over another. By default, the Elevation of a segment is Ground (zero). When two segments overlap but do not actually connect in the real world, the value of Elevation for each segment must be different. This ensures that the Waze problem detection system doesn’t flag the spot where two segments overlap as a location where a junction might be needed.”
So should we only be using ground to 5 for navigable roads?
Yes, though don’t worry about changing elevation of existing junctions. Waze will give us a different mechanism for indicating tunnels, so negative elevations will allowable in the future.
I think I remember reading that this is not the case any more - i.e. MPs no longer get raised.
I’ve seen lots of junctions like this with turn lanes etc where there is no connection and I haven’t been plagued with MPs.
It is true using different elevations stops the ‘junction’ button appearing if you select both segment in WME so it was done to highlight that these shouldn’t be joined and prevent mistakes - but since the elevation do now get rendered in the Live Map I prefer to see the correct level used (usually Ground).
Really? So there’s no speed data for the Dartford Tunnel … or most motorway ramps (don’t really know why these are negative anyway)?
I think I might have to withdraw my statement about speed data for tunnels, as I cannot find any reference to it.
Carry on!