Vulnerability assessment of urban road traffic systems based on traffic flow

The vulnerability assessment of urban road traffic systems is of great significance in urban management, particularly for ensuring their safety and sustainable operations. The majority of existing work focuses mainly on road network performance from the perspective of its structure but ignores analysis of its functional vulnerability. As such, this paper proposes a novel framework for analysing the vulnerability of road networks based on their real traffic flow. Specifically, a weighted road traffic network model is first constructed with the traffic flow obtained by using a user equilibrium model, which is built on the real original-destination data extracted from taxi trips. Second, a comprehensive indicator for node importance is introduced by integrating the entropy weight method with the technique for order preference. The vulnerability of a network in different scenarios is analyzed from both the structural and functional perspectives. Finally, several experiments have been conducted on the road networks in Haikou, China. The experimental results show that the proposed framework performs well. In addition, we find that nodes with a higher weighted betweenness have a greater impact on the overall vulnerability of a network, and the network travel time under the comprehensive indicator is correlated positively with flow loss.