Using the Solution Space Diagram in Measuring the Effect of Sector Complexity During Merging Scenarios

Abstract

When designing Air Traffic Control (ATC) sectors and procedures, traffic complexity and workload are important issues. For predicting ATC workload, metrics based on the Solution Space Diagram (SSD) have been proposed. This paper studies the effect of sector design on workload and SSD metrics. When considering the SSD in evaluation of a sector, each aircraft within the sector introduces a zone of conflict, the Forbidden Beam Zone (FBZ), on the SSD. The properties of these FBZ are systematically studied to increase understanding of the SSD usability in assessing workload and sector complexity. The effects of sector design variables on Air Traffic Controller (ATCo) workload and also SSD properties were evaluated. Example of sector properties are, number of streams to be merged, the merge angle, the proximity of incoming aircraft and the variability of traffic mix of small and large aircraft. Based on the findings, each sector design variable leads to different effect on both workload and SSD properties. Apart from that, correlation between the workload and the SSD properties were found to be in a higher level than of the number of aircraft within the sector, proving that the SSD-based analysis to be a good workload indicator. These correlations were studied based on two different groups of subjects with ranging experience in order to demonstrate the robustness of the method.