Exploring Urban Density

Abstract

Density in urban areas is not a simple concept. It can be defined in a variety of ways. This paper presents alternative measures of urban density and compares how they perform across a set of 59 large urban areas in the United States in 2010. Population and housing unit densities show similar patterns, though with differences for some areas with extreme population-housing unit ratios. The housing unit densities do perform better in the estimation of the negative exponential model of density decline. The conventional measure of total population divided by the total land area of an urban area differs from various measures of the density of residential areas. The absence of data precludes the calculation of residential densities for large numbers of urban areas, but using block data and excluding blocks that are completely or largely nonresidential makes possible alternative measures coming closer to residential density. When used to estimate the negative exponential model, these measures produce higher estimates of the parameters and a significantly greater goodness-of-fit. Weighted density calculated as the mean of the densities of small areas weighted by their population is another, completely different measure. These are higher than convention densities, with the differences being larger for those urban areas with greater internal variation in density, such as areas with high density cores and low density peripheries.