Specific for the French Italian and Swedish networks. Applicable if trackside HABD is not TSI compliant, direction of measurement of trackside Hot Axle Box Detector. If the direction of measurement is: — the same as the direction defined by the start and end of the SoL: (N) — the opposite to the direction defined by the start and end of the SoL: (O) — both directions: (B). This property was previously a datatype property with domain Track and range string. As its values are a list of three predefined values, it is now a SKOS. The allowed values for this property belong to the SKOS Concept Scheme http://data.europa.eu/949/concepts/hot-axle/HotAxleBoxDetectorDirections