Interactions between convergence angle, traffic load, and altitude distribution in air traffic control

Past research suggests that the ability of air traffic controllers to determine whether two target aircraft will pass too close to each other is mediated by the convergence angle between them: wider convergence angles are associated with impaired conflict detection (especially with high traffic loads), due to the greater required amount of visual scanning. We attempted to generalize these results in more ecologically valid displays (a) with broader altitude distributions than those used in previous studies; and (b) where controllers couldn't be certain that a conflict existed on every trial. Fourteen air traffic controllers performed a standard conflict detection task, during which both convergence angle and traffic load were systematically manipulated. Though we observed large effects of traffic load on both accuracy and response times, convergence angle did not affect performance, even at high loads. Thus convergence angle may play only a limited role in mediating controllers' conflict detection performance in many actual air traffic displays.