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Office of the Assistant Secretary for Research and Technology
ITS Joint Program Office

ITS Standards

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ITS Standards have been developed for many of the architecture flows in the National ITS Architecture. Click on the standard(s) to view the architecture flows and their communication requirements. More...

Connected Transportation Interoperability (CTI) 4001 v01 – Roadside Unit (RSU) Standard
This document establishes a non-proprietary, communications-agnostic, industry consensus Roadside Unit (RSU) Standard. An RSU is a transportation infrastructure communications device that is a part of a Cooperative Intelligent Transportation Systems (C-ITS) transportation environment. The goal of such an environment is to reduce the number of fatalities and injuries on roadways, improve mobility, and reduce environmental impacts of transportation systems. Commonly known as the Connected Vehicle (CV) environment in the United States (US), it includes both connected human-driven vehicles and connected automated vehicles (CAVs). The terms Vehicle-to-Infrastructure (V2I) and Vehicle-to-Vehicle (V2V) are used to reflect the exchanges of messages within the CV environment. The vision for this technology has expanded to include all types of travelers including pedestrians, cyclists, multimodal travelers, and other vulnerable road users (VRUs), and is referred to as Vehicle-to-Everything (V2X) technology and V2X communications.

For more information on how to obtain this standard:

Recent Development Status: Amendment 1 to Version v01: Published (Sep 2022)

Current Published Version: Version v01, Published in Sep 2021