Bay Area Bike Stations

The 'Race Ratio' is the percent of people of a race within X miles of the facility (or point) divided by the national average (Census 2010). If the ratio is greater than 1 that means that people of that race are disportionately located within X miles of that type of facility (or point). The national averages (2010 Census) are 0.9497% American Indian, 4.753% Asian, 12.61% Black, 16.35% Hispanic, 2.918% Multi-Racial, and 63.75% White (this exceeds 100% due to how the Census counts Hispanics).

The Income Ratio is the median household income (ACS 2010-2014 5 year average) of people within x miles of the facility (or point) divided by the national average ($52,762). If the ratio is lower than 1, that means that low-income people are disproportionately located within X miles of that facility (or point).

Geographical units for Race: Blocks up to 5 miles, block groups up to 50 miles, then census tracts.
Geographical unit for Income: census tract

 Distance (in miles)
 0.10.250.512.551025
American Indian0.650.660.70.70.70.680.60.61
Asian34.2238.6136.0735.3927.2825.132.7328.04
Black7.136.646.636.365.665.2267.39
Hispanic11.9512.914.8316.1319.7422.6220.922.45
Multi-Racial3.734.024.154.284.564.84.895.26
White42.8838.3838.9938.743.8643.5736.7938.11
Population Sample19k138k569k2,430k11,403k27,989k66,456k170,392k
Density170,392k170,392k170,392k170,392k170,392k170,392k170,392k170,392k
 
Income$52k$52k$60k$59k$72k$82k$85k$88k
Population Sample6,992149k566k2,429k11,305k27,806k66,334k170,602k

Note: for the larger distances the total population will exceed that of the US as people who live near multiple facilities (or points) are counted once for each facility (or point).

The Population Sample is all of the people in that radius that have race or income data. The population sample for income data can differ significantly from that of race, especially at small radiuses (1 mile and less) due to income requiring a larger geographical unit of analysis. Also, the income population sample size may include as few as one census tract. You can estimate the number of census tracts by dividing the income population sample by 4000. Any income population sample size that only includes several census tracts is subject to a large confidence interval.

User Notes
http://feeds.bayareabikeshare.com/stations/stations.json



Technical Notes

Execution time: 4 seconds

Credits: JusticeMap.org, Energy Justice Communities Map, Census Bureau (2010 Census and 2010-2014 American Community Survey).

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