Z-Levels

Z-level is an integer from -9 to 9, which specifies the vertical level of streets: One number for the start of the link (Z-from) and one for the end of the link (Z-to).

The information is used during the import process to adjust coordinates slightly (10 cm) to prevent nodes at different Z-levels to have the same coordinates. The modification is only applied, if Z-level<>0.

It is commonly found in commercial street databases (HERE, TomTom, ITN etc.).

If your dataset contains fromnode and tonode for the links instead of Z-level information, use ExternalNodeId2ZLevels for a transformation.