This example shows a force-directed network of flight routes between eight major US cities. Node size represents hub importance based on connection count, and gray lines indicate direct flight paths. The visualization uses D3 v7’s `d3.forceSimulation`, applying `forceLink`, `forceManyBody`, `forceCenter`, and `forceCollide` to position nodes. Users can drag nodes to reposition the graph, which renders as an SVG with white-stroked circles and city labels.