This chart combines three encodings to show automotive trends across model years. It plots average MPG and horsepower as colored lines on a shared left axis, while average weight appears as bars using a separate right axis. The visualization aggregates individual vehicle records from the seaborn MPG dataset using `d3.rollups` and `d3.mean`, then renders an SVG with `d3.line`, `d3.scaleBand`, and multiple `d3.axis` components. A text annotation highlights the observed rise in fuel efficiency.