This standard specifies the conceptual and logical data model and physical encoding formats for geographic databases for Intelligent Transport Systems (ITS) applications and services. It includes a specification of potential contents of such databases (data dictionaries for Features, Attributes and Relationships), a specification of how these contents shall be represented, and of how relevant information about the database itself can be specified (metadata). The focus of this standard is on ITS applications and services and it emphasizes road and road-related information. ITS applications and services, however, also require information in addition to road and road-related information. Typical ITS applications and services targeted by this International Standard are in-vehicle or portable navigation systems, traffic management centres, or services linked with road management systems, including public transport systems. The Conceptual Data Model has a broader focus than ITS applications and services. It is application-independent, allowing for future harmonization of this standard with other geographic database standards. In order to deal with a multiple data provider environment and new applications, conceptual models, features, attributes and relationships are expanded in GDF5.1. GDF5.1 is separated into two parts according to methods of utilization. GDF5.1 Part 1 defines application-independent map data shared between multiple sources. GDF5.1 Part 2 defines map data used in automated driving systems, cooperative ITS, and multi-modal transport.