| Concept definition: |
The traversability provided at a four-way <ROAD_INTERCHANGE> between the entry segments of adjacent <ROAD>s. Each entry segment necessarily connects to an opposing exiting segment (two pairs are thus formed) and optionally to either of the adjacent left or right entry segments. The first entry segment is that entering the interchange in the <DIRECTION> of the associated <BRIDGE_SPAN>; the remaining three entry segments are ordered in a counter-clockwise <DIRECTION> with the third entry serving as the exit for the first entry, and similarly the fourth for the second. The value is formatted in a Basic Latin string containing exactly four characters with the ith character corresponding to traversability from the ith entry (I = 1, 2, 3 and 4). Each character position in the string contains one of the characters N (no turns), R (right turn), L (left turn) or B (both right and left turn). EXAMPLE "NRBL" means no turns from first entry; right turn from second entry; right and left turn from third entry; and left turn from fourth entry. |
