Intelligent Transportation Systems (ITS) can only operate successfully if selection and training of personnel is carried out in a systematic, theoretically sound way. Given the increasing responsibility of operators working in the control room, a scientific analysis to develop requirements and specifications for training and selection is necessary. Despite the increasing deployment of ITS in industrialized countries, so far no systematic, empirically supported requirements analysis – including ability-level as well as the task-level – has been done for Traffic Operators in Traffic Management Centers (TMCs), Tunnel Operation Centers (TOC) and Urban Traffic Control Centers (UTC). In this paper, we establish a general requirement profile – including knowledge, skills and abilities – for operators in all three different center types and highlight the differences for TOs in TMCs, TOCs and UTCs. Moreover, we draw consequences for selection processes for potential operations employees and provide an overview of tasks that have to be taught specifically. The methods and results shown are particularly helpful for researchers and practitioners in the operational field of ITS.