This International Standard specifies the following. • Reference architecture for probe vehicle systems and probe data. This reference architecture provides a general structure for probe vehicle systems within which a wide range of actual probe vehicle systems can be built whose physical characteristics may differ (e.g., in their choice of communications medium). The reference architecture is used to: — clarify the major building blocks and logical interconnections of probe vehicle systems for which this standard will be used; — categorize probe data in accordance with the information model described below. • Basic data framework for probe data elements and probe data. This framework specifies how to define probe data elements and probe messages. Specifically it provides the following. — Rules for mapping information models (as defined in ISO 14817) of probe data to probe data elements/messages. The information models show the logical structure of entities and concepts involved in probe data. — Required characteristics of probe data elements and probe data messages. — The notation for probe data elements/messages (in XML). — Rules for using core data elements and basic data elements (see below), and extensions of data elements in each application domain. • Core data element definitions. Core data elements are basic descriptive elements intended to appear in every probe message. These are the location and the time at which the probe data was sensed. • Initial set of probe data elements. These elements will be commonly used in typical probe data enabled application domains, such as traffic, weather, and safety. Standardizing these probe data elements facilitates the development of probe vehicle systems and the distribution of probe data. This is not intended to be an exhaustive listing of probe data elements. • Example probe messages. These messages define how probe data elements are combined to convey information to probe processing centres. This is not intended to be an exhaustive listing of probe messages. Figure 1 depicts the scope described above. To completely define probe processing, the standardization of probe data elements and probe messages is not sufficient. Standards are also required for processed probe data (the output of probe processing) and downlink elements and messages (to convey these results to vehicles and other users). This International Standard prescribes an initial set of probe data elements that are important for transmission from vehicles to land-side processing centres. The standardization of other probe data issues will be addressed in future work.