Physical

An icon shown as a purple parallelogram representing the Physical View

The physical view describes the transportation systems and the information exchanges that support ITS. In this view, the Architecture is depicted as a set of integrated Physical Objects (Subsystems and Terminators) that interact and exchange information to support the Architecture service packages. Physical Objects are defined to represent the major physical components of the ITS Architecture. Physical Objects include subsystems, and terminators that generally provide a set of capabilities more than would be implemented at any one place or time. Subsystems are Physical Objects that are part of the overall Intelligent Transportation System and provide the functionality that is 'inside-the-boundary' of ITS. Terminators are Physical Objects that lie at the boundary of ITS and supply information needed by ITS' functions or receive information from ITS. Functional Objects break up the subsystems into deployment-sized pieces and define more specifically the functionality and interfaces that are required to support a particular Service Package. Information Flows depict the exchange of information that occurs between Physical Objects (Subsystems and Terminators). The information exchanges in the Physical View are identified by Triples that include the source and destination Physical Objects and the Information Flow that is exchanged.

The Physical view is related to the other Architecture views. Each Functional Object is linked to the Functional View, which describes more precisely the functions that are performed and the details of the data that is exchanged by the object. Physical Objects and Functional Objects are also depicted as Resources in the Enterprise view, which describes the organizations that are involved and the roles they play in installing, operating, maintaining, and certifying all of the components of the Architecture.

In addition, the physical view includes a notional hierarchy. Considering the architecture from its most abstract (highest) level, the physical view describes interactions between support, center, field, traveler and vehicle systems as shown in the figure below.

Physical layer 0 diagram

(Note that in this diagram we focus only on the primary interactions between systems; if we consider all possible interactions in the architecture, the connections between systems include more possibilities, as illustrated in this enhanced figure.)

Physical layer 0 diagram

Finally, if we wish to consider all physical objects in the Architecture, we can illustrate a comprehensive top level diagram. This diagram separates objects that do not include functionality and calls them 'terminators', as they serve as either sources or sinks, but not functional elements.

For details on how the physical view is structured, see the physical viewpoint specification.