IN-PERSON Barcelona Livable Cities. Section A

Abstract

Population density affects walking (as measured by the number of steps), which may impact people’s health. In areas with low population density, people tend to use passenger cars and take fewer steps. Conversely, in areas with high population density, the distance to destinations is shorter, potentially reducing the number of steps taken. Therefore, is there an optimal population density where the number of steps is maximized? This is the question addressed in this study. Tanishita and Wee (2017) found that the estimated population density that maximizes steps is about 11,000 persons/km². Wu et al. (2021) also indicated that the estimated population density that maximizes the number of steps is about 7,000 persons/km² in Zhongshan, China. However, these studies were limited to specific years and city ward units. In this study, we used data collected from approximately 22,000 individuals in 164 regions across Japan between 2017 and 2019 to determine the relationship between regional population density and walking behavior. We employed an additive model considering individual attributes such as age, BMI (body mass index), and sleeping hours. The results showed that population density significantly influenced walking, with a modest positive correlation that diminished as density increased. The population density elasticity of the number of steps was 0.04 in a simple log-linear regression model. Applying a quadratic function, the estimated population density that maximizes the number of steps was around 13,000 persons/km². Additionally, people in their early 50s and those with a BMI in their early 20s walked the most, indicating differences in the number of steps taken based on individual attributes.