This interactive D3 v7 chart compares in-place (bank) and loose densities for four FHWA earth materials—dry, damp, and wet loam, plus topsoil—displayed as filled and open circles per row, with bank-to-loose ratios on the right. Users toggle between lb/cu yd and kg/m³ units via radio buttons. The SVG uses `d3.scaleBand`, `d3.scaleLinear`, and `d3.axisBottom`, with data from the US Construction Estimating Constants dataset and FHWA’s Exhibit 5.1 A.