Percolation-based congestion analysis and its applications in transportation networks

Congestion is the most important factor compromising the efficiency of transportation systems. Fundamental laws of traffic flow theory have been studied intensively for decades and there is a deep understanding of congestion dynamics in transportation networks at different scales. In comparison, however, the attention to the organization of congestion is only heightened recently in the area of complex networks. We use percolation theory, a heavily applied tool in statistical physics, to study the conflict between passenger flows and different levels of congestion in transportation networks. Thereby, a theoretical framework is proposed that allows for identifying the evolving critical bottleneck links in road and public transportation networks. We show that treating these bottlenecks guarantees a decisive improvement in network efficiency.