Traffic Performance Assessment Methodology of Degraded Roadway Links Following Hazards

Abstract

Posthazard traffic networks are often disrupted, not only because of direct impacts on transportation infrastructure but also because of indirect impacts originating from the interdependent nature of infrastructure systems and environments. These indirect impacts include roads blocked by debris from adjacent buildings, traffic accidents, or fallen trees or light poles. For all these scenarios with partially blocked roads and bridges following extreme events, traffic capacity and travel time are very different what they are with intact road infrastructures and, therefore, become hard to predict. A new simulation methodology of the traffic performance of partially blocked roadway and bridge links due to hazardous events is proposed in this paper. The methodology was based on improved microscopic-scale traffic flow simulation techniques that can be applied to degraded road/bridge links with various types of obstacles (different sizes, numbers, and distributions). Following validation with the published results of traffic congestion induced by a work zone, two typical partially blocked scenarios resulting from infrastructure damage and accidents were numerically analyzed to demonstrate the feasibility of the application of the methodology to the traffic performance prediction of disrupted roadways due to extreme events. Parametric studies, such as the impact of truck proportion, blockage configuration, and traffic control measures, were also conducted. It was found that the proposed framework can predict the traffic performance of degraded transportation systems due to various causes, which could contribute to a wide array of future studies, such as community resilience modeling, emergency response and evacuation planning, and so forth.