Consequenties voor het milieu door de bochtafsnijding bij het Nauw van Bath in de Westerschelde en aanbevelingen voor de waterkwaliteitsbewaking

Onderzoek naar effecten van de aanleg van het Baalhoekkanaal om de ecologie van de WesterscheldeWesterscheld

Ramp Metering with Microscopic Gap Detection Algorithm Design and Empirical Acceleration Verification

Freeway on-ramp areas are susceptible to traffic congestion during peak hours. To delay or prevent the onset of congestion, ramp metering can be applied. A Ramp Metering Installation (RMI) controls the inflow from the on-ramp to the main line so that the total flow can be kept just below capacity. Current ramp metering algorithms apply macroscopic traffic characteristics, which do not entirely prevent inefficient merging behavior from occurring. This paper presents a microscopic ramp metering approach based on gap detection in the right-hand lane of the main line. As preparation for the analyses, trajectory data were collected, by which the mean and standard deviation of driver accelerations were calculated. Simulation, including driver acceleration, is used to test the ramp metering controller. Overall, it shows travel-time savings compared with no-control and compared with existing macroscopic ramp metering systems. Especially during periods of very high main line demand, the microscopic control approach is able to achieve additional travel-time savings. This way, the proposed algorithm can contribute to more efficient road usage and shorter travel times.Transport and PlanningTransport and Plannin

Solution space concept: Human-machine interface for 4D trajectory management

The current evolution of the ATM system, led by the SESAR programme in Europe and the NextGen programme in the US, is foreseen to bring a paradigm shift to the work of the air traffic controller. Rather than the current primarily tactical control method, one aims for the introduction of more strategic, 4D (space and time) trajectory management. In both programmes a central role is foreseen for the human operator, aided by higher levels of automation and advanced decision-support tools. Previous work has shown promising results in the design of such automated support tools, however, issues with controller acceptance and intuitiveness were found to be key for their overall acceptability. This paper presents a concept decision-support tool for 4D trajectory management that aims to overcome these issues by directly visualizing action-relevant solution spaces. Rather than imposing a certain control strategy, the solution space visualizes all possible control actions, regardless of their optimality. Results of preliminary validation experiments with partial implementations of the solution space representation demonstrated the viability of the concept, but also highlighted areas for improvement.Control & Simulatio

Exploring the potential benefits of multi-aircraft trajectory manipulation in future air traffic control

Future Air Traffic Management is expected to shift towards four dimensional trajectory (4DT) management, requiring new decision support tools for air traffic controllers to meet stringent time and position constraints. In previous work, a prototype human-machine interface has been developed for 4D trajectory manipulations of single aircraft. This paper describes a tool for multi-aircraft manipulation and investigates its potential control efficiency benefits. A human-in-the-loop experiment (N = 13) has been conducted using scenarios with sector disruptions and varying conflict geometry. Results show that participants preferred to use multi-aircraft manipulation for groups of aircraft having small convergence angles. Since the current implementation involves re-routing all selected aircraft through one common waypoint (referred to as a 'merge point'), extra additional track miles were flown and airspace robustness reduces. Regarding efficiency and safety, multi-aircraft trajectory manipulation seems favourable only for smaller convergence angles, although this also depends on the way the operators place the aircraft merging points. For future development, attention should be devoted to making flight efficiency constraints of each aircraft more salient, enabling controllers to better time the rerouting multiple aircraft and more fairly distribute re-routing costs.Control & Simulatio