The ITS deployments affecting CEF corridor performance and reliability are undertaken in addition to ITS corridors, C-ITS corridors, multimodal ITS implementations and ITS deployments in urban areas and national regions linked to the CEF corridors. These deployments involve several public and private stakeholders. The EU ITS corridor consortia and the C-Roads platform agreed in November 2021 to cooperate closely in all technical areas to support the European network of experts that need to work together towards European harmonization where needed. Herewith all European road authorities and road operators teamed up in an exemplary readiness to continue the work towards European harmonization of ITS systems and digital services based on the EU EIP Reference handbook. The Cross Corridor Cooperation (CCC) task is contributed to the cooperation of all actors in terms of exchange of knowledge, technologies, and best practices towards the harmonisation of ITS systems in Europe. The evaluation cooperation and cooperation in ITS deployments are targets of CCC, too.