Hi Steve,
1) Why do we need the new class NumberCoord?
There is always more than one way to do anything... so no you don't need it. I suggested it because it requires no memory and it expresses the relationship that a CoordNode is a NumberNode.
OK, my reason for prefering the bit flag is that it allows to change a normal coord to a "NumberCoord" without allocating a new object. I think that makes life easier.
2) Is a CoordNode always also a number node? Or is it possible
Yes a CoordNode is a number node.
to combine the numbers for multiple arcs? I guess that would allow to save some bytes.
You can skip number nodes if there are no known numbers on that part of the road. But otherwise it is from number node to number node. Arc is a NOD concept, house numbers are purely a NET concept. I know that we don't support a NET only build but if we did it could have house numbers without any routing at all.
OK, I may try to code the support for NET without NOD later. Gerd