Relations among Enroute Traffic, Controller Staffing and System Performance

Abstract

Relations are estimated among enroute air traffic, controller staffing and performance of controllers and ATC system. Controller staffing is found to increase at least linearly with air traffic in the US National Airspace System. Findings in literature review, FAA controller staffing models, FAA standards, and results of analyses support this finding. Measures of controller performance, controller workload and models are developed to estimate relations between controller performance and air traffic in sectors and centers of the NAS. It is found that controller performance is not affected by air traffic congestion within sectors and centers. The estimated relations may be biased by factors such as spatial and temporal propagation of delays in the NAS, ATC procedures used to delay flights away from the source of airspace congestion, strategic and tactical planning performed by ATC system and different traffic management processes and programs implemented for traffic flow management in the NAS. There is a need to evaluate the performance of ATC system in managing air traffic and minimizing delays in the entire NAS. It is found that a hyperbolic function is applicable for relating delays and enroute traffic volumes in the NAS. Monthly models estimated using monthly measures of delays and enroute traffic volumes perform better than daily models. Monthly models estimated for same calendar month of successive years show the best statistical fit. It appears that the enroute operational capacity of NAS can differ considerably for different months. Ground delays, taxi out delays, gate departure delays and airport departure delays used to reduce air delays due to enroute congestion are identified using the monthly and month-specific models.