An experimental approach to measuring the effects of a controller conflict probe in a free routing environment

The unstructured traffic environment that is gradually evolving in the National Airspace System may necessitate decision aiding tools to help controllers manage aircraft traffic efficiently and within acceptable safety and workload levels. An experiment was designed to assess the effect of conflict detection and trial planning resolution aids and traffic conditions on the performance of controllers and the efficiency of flight. Twelve controllers participated in a high-fidelity simulation study in the Indianapolis Center dynamic simulation facility using the user request evaluation tool (URET). Study results indicated that URET clearly improves the acceptability of operations and may enhance safety, particularly in the unstructured environment. In addition, the study findings strongly support a shift toward more strategic air traffic control with conflict probe as well as a significant increase in the contribution of the D controller to the primary sector tasks. Because of study limitations, it was not possible to associate any quantitative estimates of airspace user benefits with the potentially more efficient resolution strategies. The results and experimental approach are discussed in terms of their contribution to measurement methods and issues in the evolutionary progression toward a free flight-based air traffic system.