A graph-based approach to nominal terminal routing

As the air transportation system moves toward trajectory-based operations, there is a greater need for route modeling, especially in the terminal airspace where traffic flows twist and turn and many do not follow any currently published route. This paper presents a graph-based algorithmic method for defining nominal terminal routing from historical flight tracks. First historical traffic is used to generate a directed graph. Then Djikstra's shortest path algorithm is used to identify the shortest yet most commonly used paths through the graph. There were many different nominal routes between different engine types due to the distinct differences in engine performance characteristics. A comparison of graph-based shortest path routes to two other methods (manual and k-means) showed how the method could rapidly produce similar distinct dominant terminal area flows. Finding shortest paths from all links of a sufficient weight, rather than just source nodes, identified more route options depicting standard path control techniques in addition to the dominant route. This method may be used to rapidly prototype route models to assess trajectory-based terminal area concepts.