Urban mobility and segregation examined through networked travel activity

Individuals make travel decisions every day that feed into a vast network of spatial interactions. Unfortunately for some, ongoing economic, social and psychological effects related to the United States’ history of racism, segregation, and discrimination have led to significant disparities in urban mobility across racial groups (Ray and Preston 2009). The effect of segregation in residential neighborhoods has been extensively studied, and more attention is being brought to other spatial contexts in which people interact. However, comparatively little research has taken a comprehensive approach to both segregation and urban mobility by analyzing residential, work and social environments together. The utility of this approach lies in the ability to characterize physical spaces by their potential for interaction between racial groups, and whether or not group networks of activity reveal the different accessibility levels of neighborhoods in an area. This chapter seeks to address how networks and associated metrics can help to explain broad urban mobility patterns and the differences that exist between racial groups. In order to model urban mobility, we first construct networks of travel activity based on race. We then derive various network-based measures and a neighborhood-interaction potential matrix that compares travel between neighborhoods in our study area. We present results for the Los Angeles and Orange County area as a case study because it has a large, diverse population and continues to be a focus of segregation research (Johnston et al. 2006).