Z-level Information (ZLevelCrossing)

The Z-level (ZLevelCrossing File Geodatabase Table) table contains Z-level information for coordinate pairs to model a relative stacking order when navigable links are crossing other navigable links, or specific cartographic features (for example, railroads, water).

The Z-level information can be used to render the road network correctly when it crosses other map features (for example, this link should be drawn on top of that link).

The ZlevelCrossing table provides an explicit stacking order where two links are crossing at different Zlevels. The ZlevelCrossing table publishes an upper Link or Node, and a lower Link or Node. This Upper and Lower feature information explicitly defines which feature should be drawn on top of another feature.

The ZlevelCrossing table only publishes entries when Z-level information is relevant: when Links are crossing not at grade (so at different Z-levels). In all other situations no entry is generated in the ZlevelCrossing table.

Field Name Description Values
OBJECTID Internal feature number Sequential unique whole numbers that are automatically generated.
UPPER_LINK_ID Upper Link ID Unique identifier for the upper link in the z-level crossing.
UPPER_NODE_ID Upper Node ID Unique identifier for the upper node in the z-level crossing.
UPPER_ZLEVEL Upper Z-Level The z-level of the upper link or node in the z-level crossing.
LOWER_LINK_ID Lower Link ID Unique identifier for the lower link in the z-level crossing.
LOWER_NODE_ID Lower Node ID Unique identifier for the lower node in the z-level crossing.
LOWER_ZLEVEL Lower Z-Level The z-level of the lower link or node in the z-level crossing.