Architecture Reference for Cooperative and Intelligent Transportation

The communications view The physical view The functional view The enterprise view

ARC-IT 8.2 includes changes to the physical, communications, and enterprise views of the National ITS Reference Architecture to improve their accuracy in reflecting security requirements, reflect the latest communications standards mappings, and provide updated enterprise or institutional roles and relationships. Read more...


November 2018 – Both RAD-IT and SET-IT have been updated with new features and performance improvements. See below for details.


RAD-IT 8.2 has been substantially upgraded to provide improved integration with SET-IT and corrects issues with conversion and the Interfaces tab. Read more...


SET-IT 8.2 includes updated integration with RAD-IT and corrects known issues. Read more...



The Architecture Reference for Cooperative and Intelligent Transportation (ARC-IT) provides a common framework for planning, defining, and integrating intelligent transportation systems. It is a mature product that reflects the contributions of a broad cross-section of the ITS community (transportation practitioners, systems engineers, system developers, technology specialists, consultants, etc.).

ARC-IT is a reference architecture: it provides common basis for planners and engineers with differing concerns to conceive, design and implement systems using a common language as a basis for delivering ITS, but does not mandate any particular implementation. ARC-IT includes artifacts that answer concerns relevant to a large variety of stakeholders, and provides tools intended for transportation planners, regional architects and systems engineers to conceive of and develop regional architectures, and scope and develop projects.

To get started, begin with the menu bar above:

  • Architecture contains links to all of the content inside the architecture, and describes the structure of the architecture. In particular:
    • Service Packages provide the most straightforward entry into ARC-IT content. Similar in appearance to CVRIA applications, these include all of the services defined in both CVRIA and the National ITS Architecture 7.1.
    • Views and its sub-menus provide view-specific content; if for example you are looking for a particular information flow, or a particular communications profile, browse the relevant physical and communications sections here.
    • Methodology and its sub-menus describe the structure of the architecture: how it is built, how the artifacts within are inter-related.
    • The Security section describes how security is addressed throughout the architecture and provides links to cross-cutting security content.
  • Architecture Use describes how to use ARC-IT, from the perspective of a regional architect or project systems engineer.
  • Architecture Resources provides access to all ARC-IT content in user-downloadable forms. Notably this also includes access to our tools: RAD-IT and SET-IT, that provide you with means to manipulate the architecture according to models' rules, customizing the reference architecture to your regional or project needs.
  • Architecture Terminology provides those definitions that permeate these pages.
  • Contact the Architecture Team gives you a direct line to the source. We want to hear from you! If you have questions, concerns or find an error (say it isn't so!) we'd like to know about it!