We use the two-step floating catchment area method to calculate spatial accessibility scores for Census tracts in Arlington County by race. The four racial groups considered were White, Black, Asian, and Other (any racial group not included in the previous three), where the categorizations of race followed those defined by the American Community Survey. These scores give a measure of accessibility for the population of each race in each tract to the parks and their amenities in Arlington County and are calculated as the summation of the supply to demand ratio for each park contained in the catchment area of the Census tract. The supply of a park is defined by its acreage and its demand is defined by the total population count of a racial group in a Census tract. The catchment areas for both the parks as well as Census tracts are defined by a distance of one mile. Census tracts with higher scores are considered to have more accessibility to parks and their amenities. All considered parks are displayed as shaded areas underneath the tract polygons in the following maps. Note that the scores are not comparable across racial groups and instead should be used to compare accessibility within a given racial group.
Here, we consider every park in Arlington County when calculating the accessibility of the Census tracts. We can see that the West to Southwest area of Arlington County has the highest level of accessibility. This observation aligns with the location of the parks given that that same area has many of the largest parks in the County. For the Black, Asian, and other populations, however, there are also high levels of accessibility in the Northern region. This is due to the fact that those areas have a number of large acreage parks combined with the low numbers of people who identify as Black, Asian, or other.
Here, we consider only those parks in Arlington County that have playgrounds when calculating the accessibility of the Census tracts. In contrast to the maps above considering every park, the Western tracts of Arlington County have the highest accessibility for all racial groups. This is primarily due to the fact that most of the parks containing playgrounds are in the Western tracts.
Here, we consider only those parks in Arlington County that have free parking available when calculating the accessibility of the Census tracts. The accessibility score distributions for parks with free parking are similar to that of all parks. For the White population, the Western tracts have the highest accessibility scores due to the large parks in that area having free parking. This area again has high accessibility scores for the Black, Asian, and other populations; however, we see relatively high scores for the Northern tracts as well given the low population counts of those racial groups and the presence of large parks with parking. Interesting, we see very few if any parks with free parking in the Southern tracts of the County, which are the ones with the highest Black population.