This example shows how traffic counts for pedestrians, bicycles, and motor vehicles at a single crosswalk are visualized as a stacked bar chart. A single bar represents the total count for one lane, with each stacked segment colored according to category using D3’s `scaleOrdinal` and `schemeSet3`. The chart uses `d3.stack()` to compute the stacked series, `scaleBand` for the x-axis, and `scaleLinear` for the y-axis. The legend is built with plain HTML divs, while axes are rendered via `d3.axisLeft` and `d3.axisBottom`.