Why do Controllers Choose the Conflict Resolution Maneuvers that They Do?

Objective: This study aimed to reveal the causal reasons for maneuver preferences on the basis of the objective measures. Background: Although the effects of conflict geometry have been well documented in previous literature, empirical evidence on the influence of conflict geometry on the operator's workload, maneuver choice, and success is still lacking. Method: Thirteen undergraduate students with air traffic control (ATC) knowledge were requested to complete ATC tasks and resolve six different conflicts that were generated by manipulating two geometric features, namely, lateral (i.e., crossing, converging, and overtaking) and vertical (i.e., level and nonlevel) conflicts. Results: Crossing (p < .01) and converging (p = .05) conflicts resulted in higher workload than overtaking conflicts because of the higher geometric dimensions involved. Workload (p < .01) and performance (p < .03) were worse during nonlevel conflicts than during level conflicts. Notably, vertical maneuver led to a higher workload than other maneuver choices despite the higher preference for this maneuver. These findings were associated with visualization load. Conclusion: We failed to confirm that the resolution maneuver was chosen because of its good performance and low workload. Instead, predetermined rules (i.e., altitude, speed, and heading) were used, regardless of the workload, and the safety of the chosen maneuver for a particular conflict geometry was verified.