Texas-flavored geographic charts using real geometry. Five kinds via the kind prop, all native SVG (no library): county choropleth (254 TIGER/Line counties), TxDOT 25-district map (official MapServer boundaries), US states with TX highlighted (AlbersUsa projection, AK / HI insets handled), dot-density incident map (rejection- sampled inside the actual state outline), and origin- destination flow arcs between metros (projected from real lat/lng).
Geometry is pre-projected at build time by scripts/build-geo.mjs — us-atlas + TxDOT MapServer through Visvalingam simplification through d3-geoAlbers / d3-geoAlbersUsa. The component renders static SVG path strings; no runtime projection or topology library. Wrap in TuxChartFrame for the eyebrow + Oswald title + source-line rhythm.
flagship · 254 real counties
County choropleth — sequential maroon
Real TIGER/Line county geometry projected with d3-geoAlbers (Texas-centered, parallels at 27°N and 35°N to minimize distortion across the state). Five-step quantile-binned ramp; never linear-scale (one outlier washes out everything else). Pass a :counties="[{ fips, value }]" array to drive the choropleth; the showcase below uses a deterministic FIPS-hash demo.
Exhibit 11.01
Vehicle miles traveled per capita, by Texas county · 2024
25 districts · slate ramp
TxDOT districts
Coarser geography — easier to label, faster to read. Use for project-priority, district-submitted inventories, and MIP scoring. Districts are numbered per TxDOT engineering directive; the badge sits at each polygon's centroid.
Exhibit 11.02
Project-priority score by TxDOT district · MIP 2025 cycle
national context · AlbersUsa
US states — Texas highlighted
For proposals that compare Texas to peer states. AlbersUsa projection handles AK and HI as insets natively (real geography, not a tilegram). The highlighted state shifts to maroon brand color; everyone else uses the chosen ramp. Pass a :states="[{ code, value }]" array; codes are USPS two-letter abbreviations.
Exhibit 11.03
Federal transportation R&D dollars per capita, FY24
incident dots · distribution-as-message
Dot density
Each dot represents one event (or N events at a fixed scale). Use when the geographic distribution itself is the message — pedestrian-involved crashes, freight-crash hotspots, weather-related closures.
Curved arcs between Texas's seven primary metros (DFW, HOU, SAT, AUS, ELP, MCA, LBB). Arc width scales linearly with volume; arrows mark the destination so directionality reads at a glance.
Exhibit 11.06
Inter-metro daily trip flows, Texas · 2024
drill-in · 4-up neighborhood inset
Metro insets — companion to TuxChartGeographic
When statewide geography ends and the question turns to "what does it look like inside one metro," compose TuxMetroInset in a four-up grid. Each inset is an 8 × 6 census-tract grid plus a labelled diagonal highway overlay. The seed is the metro name, so the same metro always renders the same pattern.
Exhibit 11.04
Tract-level commute-time variability across four Texas metros
