Niebuhr, LucasLucasNiebuhrBerling, JanJanBerlingGollnick, VolkerVolkerGollnick2026-10-232026-10-232026-10-22Journal of Guidance, Control, and Dynamics (in Press): (2026)https://hdl.handle.net/11420/65437This paper presents an improved structure for an urban air route network, based on a node-edge grid. The enhanced network incorporates additional edge directions to increase routing flexibility. Flights are assigned to different flight levels according to the semicircular rule while complying with legal requirements of minimum and maximum flight altitudes. The routing algorithm integrates nonlinear penalization functions for large heading changes and large bank angles to improve passenger comfort. Furthermore, flights conducted against the primary direction of their respective flight level are penalized. The routes computed using three distinct network concepts are evaluated based on newly developed metrics for efficiency and safety. The evaluation also includes a full-day simulation of all flights to detect separation conflicts and ensure operational safety.en1533-38842026American Institute of Aeronautics and Astronautics (AIAA)Social Sciences::388: TransportationTechnology::629: Other Branches::629.1: AviationJournal Article10.2514/1.G009903