Air Route Crossing Angles Optimization Model with Different Preferences

In order to investigate the internal mechanism of influence on air traffic posed by airspace structure and to clear bottlenecks of air traffic operation at air transit network nodes, the optimization of air route crossing angles was studied. After analysing the relationship between flight time, fuel consumption, and the angles of basic intersection route structure, an integrated crossing route angle structure was set up. Then, based on the air traffic flow distribution trait of the crossing routes, a preference mathematical model was developed to optimize the crossing angles in terms of flight time and fuel consumption. Finally, a representative crossing route was selected to verify the proposed model. The results show a negative linear correlation between flight time and fuel consumption and a 0.54% increase in total flight costs if flight time is solely considered versus a 2.89% decrease if only fuel consumption is taken into account. There is, however, a 3.82% reduction in total flight costs without preferences or 5.26% （the minimum value of total flight costs obtained when flight time coefficient equals 0.4） with preferences. The average amounts of fuel consumption density, flight conflicts, and controller workloads also declined 20.41%, 56.12%, and 46.24%, respectively, but the original airspace angle structure changed a mere 11.88% after the optimization.