This network visualization shows flight routes between major cities, with node shape distinguishing hubs as diamonds versus cities as circles and link width encoding weekly flight frequency. Node colors group cities by geographic region, and labels remain visible on every node. Built with D3.js v7, it uses d3.forceSimulation with forceLink, forceManyBody, forceCenter, and forceCollide to position the network dynamically. Users can drag nodes to reposition them. The SVG rendering includes a legend, and nodes display tooltips showing city name and type via SVG title elements. Data is custom-defined in the script.