A stacked area chart displays traffic dataset values across months, with six colored categories representing different factors. The visualization uses d3.csv to load the data, d3.stack to compute the stacked series, and d3.area with d3.scaleBand and d3.scaleLinear for positioning. SVG paths render each area with an ordinal color scale, while the x-axis labels rotate for readability. A custom HTML legend with colored circles identifies each category.