The OpenCyberCity Intelligent Transportation System (ITS) integrates small scale autonomous systems, such as ground vehicles, road-side units, and small quadrotors, into a unified testbed for multi-agent robotics, smart city, and communications research. Our team developed a custom autonomy architecture built on top of the ROS2 middleware system. This system integrates inertial measurements and embedded vision processing to emulate the typical payloads on full-size experimental autonomous vehicles. The ITS communicates with OpenCyberCity’s broader MQTT-based messaging framework by bridging the ROS2 autonomy middleware. The control architecture of the ITS enables centralized or decentralized command and control of autonomous systems, which allows for different types of experiments among vehicles and the OpenCyberCity infrastructure.