EVAQ: An Evacuation Model for Travel Behavior and Traffic Flow

Traffic simulation models are helpful or even indispensable while planning or managing an evacuation. A multitude of dynamic traffic models have been developed to this end to understand and predict evacuation conditions on a road network, and the effect of traffic regulations and control measures hereon. In many earlier studies, evacuation is recognized as a special case regarding different travel large number of evacuation studies are conducted using traffic models originally developed for regular day-today traffic applications, including both microscopic models (e. studies using microscopic models, model parameters describing driving behavior (headway, acceleration, reaction time) have been adjusted for the case of emergency evacuation. These models used in past evacuation studies typically focus on traffic flow dynamics to identify bottlenecks where congestion is likely to occur and compute expected evacuation times. They do so by using a dynamic traffic assignment (DTA) model describing travel behavior and traffic flow. In spite of advances in evacuation modeling research, main shortcomings remaining in DTA models used for evacuation studies relate to (i) route choice behavior (user-equilibrium assumptions, invalidly disregarding travelers' unfamiliarity with evacuation traffic conditions), (ii) compliance behavior (actual travel decisions are modeled equal to instructed departure times, destinations and routes, invalidly disregarding travelers' preferences and compliance decisions), and (iii) network dynamics (road infrastructure is static, invalidly disregarding the impact of DTM measures and road network disruption due to the hazard). These essential aspects are typically neglected in current evacuation models, and hence in the scenario analyses when applying these simulation models. The consequences are 1) unreliable and likely wrong model outcomes and 2) being unable to, e.g., evaluate the impact of variations in traveler compliance, or test robustness of an evacuation strategy towards uncertain hazard conditions. In this paper, we propose the new DTA model EVAQ specifically tailored to the case of evacuation thereby solving the abovementioned shortcomings. The EVAQ model is described and applied to a large-scale case study of the evacuation of the Dutch metropolitan area of Rotterdam.