Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS) environments, etc.The ISO 20684 series defines data that can be used when field devices need to exchange information with other external entities (calledmanagersin this document, even if they are other field devices). Field devices can be quite complex, necessitating the standardization of many data concepts for exchange. As such, the ISO 20684 series is divided into several individual parts. This document (Part 1) introduces the ISO 20684 series and provides normative content that applies to all subsequent parts.All current amendments available at time of purchase are included with the purchase of this document.