This paper focuses on real-time traffic management facilitated by modern telecommunication technologies and advanced real-time optimization algorithms. The discussion begins with a recent European project that provides a real-time decision support system for the reduction of traffic congestion and emissions. The workflow and techniques involved therein are explained and issues and potential gaps identified. A more generic real-time decision-making framework based on decision rules and distributionally robust optimization is then introduced. The paper illustrates the wide applicability and unique advantages of such a framework with case studies on responsive signal control, use of an adaptive variable message sign, and air traffic management.