This interactive visualization explores nine years of Boston crash data from the city’s Vision Zero program, using a geographic map and a time-series line chart. The map plots individual crash locations as colored points by crash type, filtered via checkboxes, and is rendered with D3’s `d3.geoPath` and parsed GeoJSON. The line chart aggregates monthly crash counts, with colored seasonal bands and toggleable lines for each crash type, implemented using D3 scales, axes, and `d3.line`. Both views load data directly from CSV and GeoJSON files, ensuring scalable performance.