This paper delves into the Cooperative Intelligent Transport Systems (C-ITS) architecture of the on-site pilot conducted in the city of Trikala, Greece, as part of the EU-funded project, IN2CCAM. The pilot tests and demonstrates innovative Cooperative, Connected, and Automated Mobility (CCAM) services through the deployment of autonomous vehicles (AVs) and their integration with a C-ITS platform. Featuring a fleet of autonomous electric minivans on a predefined route equipped with advanced smart digital infrastructure, this initiative aligns with the city’s vision to tackle congestion, promote the use of shared transport services, and enhance the equity of the local transport system. Furthermore, a Mobility as a Service (MaaS) mobile application enables the public to plan multimodal trips, integrating on-demand shared passenger transport services with AVs, public transport services, shared micromobility solutions, and active mobility, such as walking or cycling. The proposed C-ITS architecture includes: a) AV fleet management and monitoring, b) a Green Light Optimal Speed Advisory (GLOSA) functionality to achieve smoother and more fuel-efficient journeys, c) a traffic-based green wave system to contribute to high traffic efficiency by adjusting traffic signals according to real-time congestion levels, and d) C-ITS messages between the infrastructure and the AVs to alert about uncontrolled crossings of Vulnerable Road Users (VRUs). This paper aims to outline the architectural components of this pilot and discuss future work, which will include evaluating the feasibility, effectiveness, and societal impact of the proposed innovations in the local ecosystem of Trikala.