The development of control strategies for traffic lights, ramp metering installations, and variable speed limits to improve the throughput of road traffic networks can contribute to a more efficient use of road networks. In this project, a hierarchical controller will be developed for the improvement of the throughput of a road traffic network. In this paper the research objective of this PhD project, and the direction of the solution to reach this objective will be detailed. Furthermore, it will be discussed how this algorithm can be robust, optimal, predictive, and integrated.