Arrival Route Network Design for Reducing Noise Impact in the Terminal Maneuvering Area

Designing arrival routes in terminal airspace requires deciding how inbound streams should be grouped and where the resulting merge points should be placed. This paper searches convergence topology, merge-point positions and population-aware path decoding jointly at the network scale, treating the three as a single design problem. The problem is formulated as a bilevel optimization: an outer simulated annealing loop searches convergence topologies and merge-point locations, while an inner A* algorithm with population density embedded in its edge cost generates the track segments between structural nodes. Sound energy is accumulated once per unique structural segment, independently of how many arrival routes traverse it. The method is demonstrated as a single-case proof of concept on the north-landing configuration of Runway 35 at Shanghai Pudong International Airport. Over a preference sweep from distance-only to noise-only weighting, the optimized networks outperform the published procedures in both metrics for wN∈[0.0,0.6]; at higher weights the proxy value falls further but the route length exceeds the baseline. The noise reduction forms a statistically flat plateau rather than a single working point: at wN=0.3 the model-based, population-weighted noise proxy (the modelled population above a 65 dB single-event LAE threshold) is reduced by 69.3% and the total route length by 3.4%, and the differences between neighbouring weights within the plateau are smaller than their run-to-run scatter. Attributing the reduction sequentially, a 3∘ continuous-descent profile alone lowers the proxy value by 29.1%, and the horizontal redesign of the convergence structure accounts for the remainder at 3∘ CDO. A sensitivity study across structural, algorithmic, population and acoustic assumptions shows that the reduction in the proxy is robust, whereas the route-length reduction holds only while the structural constraints are not substantially tightened.