This proportional symbol map displays transportation costs across U.S. states, with circles sized by cost and colored purple for the top 10 most expensive states or violet otherwise. Hovering reveals a tooltip with the state name and exact cost. Built with D3 v3, it uses d3.geo.path for map rendering, d3.scale.sqrt for circle radii, and topojson to draw state boundaries. The visualization includes a legend showing cost values and employs queue.js to load GeoJSON, centroid data, and a CSV of state costs.