Traffic congestion on motorways is a serious threat for the economic and social life of modern societies and for the environment, which calls for drastic and radical solutions. Conventional traffic management faces limitations. During the last decade, there has been an enormous effort to develop a variety of Vehicle Automation and Communication Systems (VACS) that are expected to revolutionise the features and capabilities of individual vehicles. VACS are typically developed to benefit the individual vehicle, without a clear view for the implications, advantages and disadvantages they may have for the accordingly modified traffic characteristics. Thus, the introduction of VACS brings along the necessity and growing opportunities for adapted or utterly new traffic management.It is the main objective of TRAMAN21 to develop the foundations and first steps that will pave the way towards a new era of motorway traffic management research and practice, which is indispensable for exploiting the evolving VACS deployment. TRAMAN21 assesses the relevance of VACS for improved traffic flow and develops specific options for a sensible upgrade of the traffic conditions, particularly at the network’s weak points, i.e. at bottlenecks and incident locations. The proposed work comprises the development of new traffic flow modelling and control approaches on the basis of appropriate methods from many-particle Physics, Automatic Control and Optimisation. A field trial is included, aiming at a preliminary testing and demonstration of the developed concepts.TRAMAN21 risk stems from the uncertainty in the VACS evolution, which is a challenge for the required modelling and control developments. But, if successful, TRAMAN21 will contribute to a substantial reduction of the estimated annual European traffic congestion cost of 120 billion € and related environmental pollution and will trigger further innovative developments and a new era of traffic flow modelling and control research.