Effective intelligent transportation systems (ITS) architectures can facilitate efficient and interoperable ITS deployments. The U.S. National ITS Reference Architecture and associated toolsets provide a definitive and consistent framework to guide the planning and deployment of ITS.

ITS architecture helps jurisdictions cooperate and harness the benefits of regional and cross-regional approaches to transportation challenges while enabling regional customization. Recent advances in technology, such as connected and automated vehicles, have made reference architecture more important than ever.

The U.S. Department of Transportation’s ITS Program recently released the first version of the ITS national reference architecture to fully incorporate connected vehicle capabilities in detail. The Architecture Reference for Cooperative and Intelligent Transportation (ARC-IT) provides a unifying framework that covers ITS comprehensively, including connected vehicle and “traditional” infrastructure ITS capabilities.

ARC-IT and the accompanying toolsets help implementers develop regional architectures to effectively meet their needs and assure regulatory compliance while facilitating efficient, secure interoperable ITS deployments. All of the ARC-IT content, including tools and training, is available at www.arc-it.net.

“With the emergence of connected vehicle technologies, interoperability has become essential, rather than merely beneficial,” says Kingsley Azubike with FHWA’s Office of Operations, whose program supports the ITS architecture. “The newly released integrated architecture supports efficient nationwide ITS deployment and interoperability.”

What’s So Different?

ARC-IT is version 8 of the National ITS Architecture. The National ITS Architecture was initiated in the 1990s to identify interfaces for standardization and address all of the original ITS user services into one common framework. That architecture framework has been continually updated to keep pace with stakeholder needs and expectations along with rapid technological evolution. The last update to the ITS reference architecture in 2015 (version 7.1) has been widely used as the basis for regional ITS architectures around the country. Concurrently, USDOT developed a separate Connected Vehicle Reference Implementation Architecture (CVRIA) to capture the connected vehicle research efforts into a single reference architecture.

ARC-IT version 8 continues the evolution of the National ITS Architecture by merging connected vehicle concepts and a new structure to address more stakeholder concerns.

ARC-IT includes a set of interconnected components that are organized into four views that focus on different architecture perspectives: enterprise, functional, physical, and communications. The hyperlinked nature of the ARC-IT Web site enables a user to start with any of these views, however, most users start with service packages. Service packages provide a slice of the physical view that address specific services like surface street control.

Users can easily navigate from component to component to find what they need. This interconnected presentation of the ARC-IT content is possible because of the traceability that is maintained between each of the architecture components.

The ITS Architecture Program will continue to work to improve ARC-IT and keep pace with changing technology and the evolution of stakeholder needs. In the near term, USDOT expects to introduce additional enterprise layer functionality and toolset features in version 8.1.

Tools and Training Available

ARC-IT also includes the release of two companion software tools. The Regional Architecture Development for Intelligent Transportation (RAD-IT) provides all of the functionality that regional architects have come to expect from Turbo Architecture, a previous tool, updated with a more modern user interface and using the ARC-IT database. The Systems Engineering Tool for Intelligent Transportation (SET-IT) provides related project architecture functionality tailored to the implementation and project specification.

Training is also available. The training page on the Web site provides a listing of online courses that walk through the ARC-IT Web site and how to use it as well as the software tools, RAD-IT, and SET-IT. FHWA also has a number of workshops and instructor-led courses to help regions work together to develop and make better use of their regional architectures as well as to apply the systems engineering process to ITS.

“We’re now starting to get more questions and interest in connected vehicles,” says FHWA’s Azubike. “Fortunately, ARC-IT with the toolsets, and the available training and workshops, provide the support to help agencies continue to expand their ITS while providing a way to consider new technologies such as connected vehicles.”

For more information, visit www.arc-it.net or contact Steve Sill at steve.sill@dot.gov.

Steve Sill is a program manager in USDOT’s ITS Joint Program Office.