A force-directed network visualization maps cities as nodes and routes as weighted links, with node colors encoding geographic region (North America, Europe, Asia). The interactive SVG chart supports dragging nodes and shows tooltips with city and region on hover. It uses D3 v7 APIs including `d3.forceSimulation`, `d3.forceLink`, `d3.forceManyBody`, `d3.forceCenter`, and `d3.forceCollide` to simulate layout, with data loaded from CSV files hosted on GitHub.