(ROAD) data include election returns, socioeconomic summaries, and demographic measures of the American public at unusually low levels of geographic aggregation. The NSF-supported ROAD project covers every state in the country from 1984 through 1990 (including some off-year elections). One collection of data sets includes every election at and above State House, along with party registration and other variables, in each state for the roughly 170,000 precincts nationwide (about 60 times the number of counties). Another collection has added to these (roughly 30-40) political variables an additional 3,725 variables merged from the 1990 U.S. Census for 47,327 aggregate units (about 15 times the number of counties) about the size one or more cities or towns. These units completely tile the U.S. landmass. This collection also includes geographic boundary files so users can easily draw maps with these data.