This example renders 960 by 500 pixel U.S. zip code trails as thin colored lines. It uses the `albersUsa` projection to display the geographic data derived from the `zipcodes.csv` dataset. The code employs the `vega-lite-api` to construct a line mark, with `d3` providing a hue-based color scale for the first three digits of each zip code, and a filter removes non-continental states. A fixed color mapping with nine hues visualizes regional groupings across the map.