Towards an air traffic control complexity metric based on workspace constraints

Previous research introduced the solution space as a workload metric for air traffic controller merging tasks. The Solution Space Diagram is a mapping of intruding aircraft trajectories to the velocity/heading plane of a considered aircraft. This mapping results in the form of conflict zones and safe areas. Choosing a velocity vector for a controlled aircraft in either one of these zones will provide an unsafe or a safe solution, respectively. Investigation with a static version of the solution space, and a dynamic version, which provides a time-varying complexity metric, indicated that this metric corresponded well with workload ratings given by subjects. This paper considers the applicability of the metric, and discusses further directions of research and development for this metric.