Studying the dynamics of urban traffic flows using percolation: a new methodology for real-time urban and transportation planning

The nature of urban areas has always been affected by the traffic flows in their streets, as the volume of the traffic influences the location of businesses, residential blocks, the development of real estate, land values, built density, etc. In this Chapter, we suggest, based on percolation theory, studying the relations between the static streets-network infrastructure and the dynamic traffic-flows on it, to gain new understandings that could be useful for various planning processes. Thus, this work will focus on unveiling the inter-relations between the dynamics of traffic flows and the urban streets-network in different areas of a city and comparing different cities. For that, we employ a percolation methodology (i.e., the removal of links that represent low speed streets) that allows us to identify spatio-temporal urban clusters where traffic flow is fluent. We tested our methodology on two datasets of London and Tel Aviv centers and analyzed the dynamics of these clusters, based on their size (in terms of street length) and their spatial stability over time and space. Our findings show the differences between the two cities as well as the differences (and similarities) between different parts of each city. We argue that this innovative method can be developed into a new, real-time decision-making tool for urban planners as well as for transportation planners. This is especially true in this new era of big data and smart technologies, that can provide planners with valuable data in real-time that can be used to improve urban life. However, currently, the main players in this field are private companies that develop real-time navigation apps that aim to find the fastest routes for their users and challenge urban and transportation planning as they change the nature of residential neighborhoods by directing large volumes of traffic to their streets. We suggest, that in order to intervene and affect urban life quality, planners and planning authorities should adopt in addition to the traditional planning tools, new adaptable and responsive tools that are based on real-time approaches. These will bridge the gap between static long-term urban planning and the flexible and dynamic urban rhythm and will enable planners to keep their role in the formation of better cities.