Travel self-containment of new towns in a polycentric city: insights from Shanghai with mobile phone data

Travel self-containment has been a main issue in new town planning since the mid-twentieth century, but its assessment has long been a challenge, especially in a polycentric city where networked structure complicates travel behavior. Traditional methods, such as census investigations can hardly trace multidirectional commuting patterns of large samples nor disclose non-commuting patterns. This paper fills the void by using billions of passive mobile phone data by which the interval of stay in a particular location and its spatiotemporal regularity can be identified to capture phone users’ travel routes. Shanghai, a polycentric city that evolved under the longstanding development of the ‘One City, Nine Towns’ polycentric urban spatial plan, is selected to assess various types of travel. The results disclose the disparity of the inward, intra, lateral and reverse journeys of commuting and non-commuting routes and reveal how the specificity of new towns, e.g. distance to the central city and metro lines, matters for such disparity.