A map of New York City displays crash locations as small black dots over borough polygons, each tinted with a distinct color. An interactive legend lets users hover over a borough name to highlight its corresponding region and dim others. Built with React and D3, the visualization uses `d3.geoMercator` and `d3.geoPath` to project and render the TopoJSON-derived borough boundaries, while crash coordinates from a CSV file are plotted as SVG circles. Hovering a legend item dims non-matching boroughs and intensifies crash point opacity for the selected area.