An evacuation risk assessment model for emergency traffic with consideration of urban hazard installations

Abstract

The Critical Cluster Model (CCM) is an optimization model assessing the evacuation risk on the scale of neighborhoods. The static evacuation risk in the CCM is measured by Bulk Lane Demand (BLD) -an index that solely depends on network structure and population of evacuees. The advantage of the CCM is having less input parameters and with relatively smaller computational cost. Moreover, the process of risk assessment by the CCM is a global optimization process. For this reason, the CCM provides a relatively ideal solution for planning emergency traffic evacuation in open spaces. Considering that hazard installations in urban areas are becoming an increasing threat to urban safety, in the paper we proposed an evacuation risk assessment model with consideration of such installations. This model was developed on the basis of the CCM by introducing two important factors: the accident risk impact factor which was negatively correlated with distance, representing the impact of hazard installation; the evacuation direction which was under the consideration of evacuating away from the hazard installation, providing feasible evacuation routes. Finally, an application of the new model was presented for Beijing, China with the support of Geographical Information System (GIS). urban public safety, Critical Cluster Model (CCM), hazard installation, traffic evacuation risk, Geographical Information System (GIS) Citation: Li Q, Chen X, Chen J, et al. An evacuation risk assessment model for emergency traffic with consideration of urban hazard installations.Due to centralization and enormous fluxes of population and productive elements in urban areas, the problems of urban public safety are characterized as unexpected with high frequency and severe impacts [1]. Once a devastating incident occurs, it can easily result in massive loss of life and property, even serious threats to economical development and political stabilization of the whole country. Generally, the sources leading to public safety problems are categorized into natural disaster, accident, public health events and social security events [2]. No matter which kind of incident occurs, it is urgently required to carry out an efficient evacuation for avoiding more people to be affected.In the past decades, the importance on evacuation in enclosed space (large building, ship, airplane, etc.) has attracted extensive concerns from the public and government. A great number of evacuation models have been developed based on computer simulation technology, such as EXITT, EGRESS, SIMULEX, EXODUS and so on [3][4][5][6]. In China, although the relevant research is just at an early stage, some representative models have also been put forward, such as the grid model, escape model in fire disaster, multiagent based evacuation model [7][8][9]. In addition to evacuation in enclosed spaces, more and more attentions have recently been shifted to the study of emergency traffic evacuation in open spaces. The primary concern of these studies was how to utilize the existing transportation net...

Power law and small world properties in a comparison of traffic city networks

“…Zhu et al [31] investigated the scaling of directed dynamical small-world networks with random responses. Some other noteworthy results can be seen in [32][33][34][35][36][37][38][39][40].…”

Development of evaluation model for intensive land use in urban centers

“…Road traffic acts as a kind of spatial support framework, orienting land expansion and development in urban centers. On the one hand, optimum accessibility facilitates the intensive development of urban centers and promotes intensification of spatial forms; on the other hand, as non-construction space in urban centers, road traffic is a negative factor for intensive land use (Li et al, 2010) 3. Construction of index system for intensive land use in urban centers…”

Risk analysis of city emergency evacuation based on multi-agent simulation

“…We can then study the evacuation capability of the road network detect the bottlenecks of the network by assessing the risk, and choose the best path etc. [2] . For example, Choi studied the minimum cost flow of a dynamic network flow with the consideration of crowded export; Cova [3] studied the best evacuatio � path through minimum cost flow and integer progranIDlmg; Cova and Church [4,5] developed the critical cluster model and assess the evacuation risk of each road and node by calculating the road capacity; Myung [6] use the eval .…”

“…uation algorithm of k-edge wearing degrees in undIrected network and fm d out the road with highest risk. LI [2] conducted the risk analysis of emergency evacuation model considering hazard based on critical cluster model. Despite these above works, in general, study of the e v. acuation in open spaces is comparatively less.…”

“…At the road intersection, only the people that satisfy the three conditions below can pass through [9,10]. a)the person is at one of junctions; b )the people to leave the current junction at one time is not exceed the threshold NJ < f, c)the next road has surplus space N2 < C. pass( n ,) = {� (N l < f a n d N2 > C) (N l > f or N2 > C) (2) In the equation , the nj represents the i-th node. f represents the road traffic flow threshold, C represents the max traffic volume of the road.…”