The Architecture Reference for Cooperative and Intelligent Transportation (ARC-IT) includes a set of interconnected components that are organized into four views that focus on four different architecture perspectives. A variety of entry points shown in the figure allow you to start with any of these components, though most people start with Service Packages. Once in, you can easily navigate from component to component to find what you need. This interconnected presentation is possible because of the traceability that is maintained between each of the architecture components.
ARC-IT is comprised of four views:
- Enterprise View considers ITS from an organizational perspective. It identifies stakeholder organizations or enterprise objects - the people and organizations that plan, develop, operate, maintain, and use ITS. It defines stakeholder roles and the relationships between stakeholders. This is also the view where needs are defined since ARC-IT, and more broadly ITS, is driven by the needs of stakeholder organizations, their constituents, and customers.
- Functional View looks at ITS from a functional perspective. Functional requirements are defined that support ITS user needs. Processes and data flows provide a structured presentation of functions and interactions that support the requirements.
- Physical View defines the physical objects (the systems and devices) that provide ITS functionality. Information flows define the flow of information between physical objects. Functional Objects organize the functionality that is required to support ITS within each physical object.
- Communications View defines how physical objects communicate. It defines communications standards and profiles that are combined into communications solutions that specify how information can be reliably and securely shared between physical objects.
Security is paramount in 21st century Intelligent Transportation Systems and ARC-IT addresses security holistically, addressing security concerns spanning all four views.
Finally, Service Packages are a service-oriented entry point that makes it easy to view a vertical slice of ARC-IT that spans all four views for a particular ITS service (e.g., traffic signal control). Since most users come to ARC-IT with a particular ITS service in mind, this is the most-used entry point for ARC-IT.