How to Use Roads (Level 2)

All the Transportation Elements forming one functional unit between two Intersections are described in the Level 2 Roads table (2r). Every Element within a Level 2 Road gets a sequential number and a Feature Type or Intersection. The first and last Elements of a Level 2 Road are always Intersection Features.

The ELEMID field can relate to the nw table if the Element is a Transportation Element (4110), or to the ig table if the Feature Type refers to an Intersection (4145).

One advantage of Level 2 Roads is that they form an even more generalized representation of the Road Network, treating the carriageways of the same Double Carriageway as one functional unit and taking Transportation Elements up to the level where routing decisions/ instructions have to be generated.

Note: Note: The generalization referred to in this context is only a logical generalization and not a geometrical generalization (i.e., a reduction of the number of shape points).

Example of a Level 2 Road

The following drawing shows an example of a Level 2 Road Feature in MultiNet^® Shapefile. It shows its comprising elements visually (geometrically) and in a tabular structure.

Figure: Example of a Level 2 Road

The orange bar indicates all the Road Element parts of a Level 2 Road (five per carriageway). The Level 2 Road shown is a highway segment giving access to a city center and overpassing all crossing Road Elements. Road Elements are split at Level 1 from Administrative boundary crossings, Built-up Area boundaries and other features.

The first Junction of the first Road Element has Junction Type "Bifurcation," which is visible and circled on the map. Linking the Element ID to the Level 2 Road ID, the complete Level 2 Road structure is retrieved, with the Intersections at the outer ends of the Level 2 Road.

More information about the other Elements that are part of these Intersections are found in the ig table.
The Type and Name of the Intersection is found in the is table.