Geospatial and proximity modeling
Geospatial analysis is a powerful tool for documenting voting access disparities. It transforms abstract counts into concrete, map-able evidence: which communities are farthest from polling places, which areas lack ballot drop boxes, and which precincts have the longest wait times. For voting rights analysts, proximity modeling ties physical access to demographic data.
Distance to polling places
The most basic proximity analysis calculates the distance from each census block (or zip code centroid) to the nearest polling location. You need two datasets: (1) geocoded polling place addresses, and (2) census block boundary shapefiles with population counts. After joining, you can calculate: average distance to nearest polling place by racial composition of the block.
If blocks with high concentrations of Black or Latino residents have systematically greater distances to polling places than predominantly white blocks, that is a disparate impact signal. The magnitude matters—a 0.1-mile difference is not the same as a 5-mile difference.
Drop box distribution
Georgia's 2021 election law (SB 202) changed the rules for absentee ballot drop boxes: counties could only have one per 100,000 voters or one per early voting site, whichever was smaller, and could only be placed inside buildings during business hours. Researchers found that the per-county cap resulted in larger counties (which tend to be more urban and more racially diverse) having fewer drop boxes relative to their voter population than smaller counties.
Wait times and line length
Long lines at polling places disproportionately affect urban precincts—and urban precincts in Georgia are more likely to be majority-minority. MIT Election Lab has documented that Black voters waited an average of 45% longer than white voters in the 2020 Georgia presidential election. The methodology: voters self-reported wait times in surveys, and those reports were matched to precinct-level demographic data.
Fulton County 2020 example
In the June 2020 Georgia primary, Fulton County polling places experienced severe wait times—some voters waited over four hours. Analysis showed that precincts with the longest wait times served predominantly Black and low-income communities. A subsequent investigation found that Fulton County had reduced its polling places from 162 in 2016 to 114 in 2020. The consolidation disproportionately reduced access in majority-Black precincts.