This interactive line chart displays monthly passenger and freight traffic to and from India, aggregated by airline. Two buttons toggle between the passenger and freight datasets, while a dropdown menu selects which airline’s routes to display. Incoming traffic appears as a blue line, outgoing traffic as red, with transitions animating the path updates over 1000 milliseconds. The visualization is built with D3 v4, using `d3.line` for path generation, `d3.scaleLinear` for axes, and `transition.attrTween` internally via D3’s transition API. The data comes from a CSV file hosted on GitHub, rendered as SVG.