Research On Modeling And Optimizing Emergency Evacuation Based On LTM

In recent years,earthquakes,tsunamis,floods,hurricanes and other disasters occur frequently,and emergency evacuation,especially large-scale emergency evacuation,has gradually attracted people's attention.A reasonable emergency evacuation plan can improve evacuation efficiency and reduce the loss of people's lives and property.Link transmission model(LTM)is a dynamic traffic loading model based on cumulative traffic of nodes.Regarding the whole link as a cell,it not only needs less storage space and less computation,but also can reproduce the flow evolution process.Emergency evacuation is a kind of unconventional collective travel behavior of evacuation group,evacuation people tend to choose the shortest route to evacuate shelter.Based on this,considering the route choice behaviors of emergency evacuees,this paper first formulate a user equilibrium model of emergency evacuation route choice based on link transmission model,which realizes the assignment of evacuation flow to emergency evacuation network.Based on the analysis of the user equilibrium model,the corresponding heuristic algorithm is designed,and furthermore its effectiveness is verified by an example.In the process of emergency plan formulation,managers evacuate the evacuated in batches.In other words,managers try to regulate their departure times.Therefore,on the basis of the above emergency evacuation route choice model,considering evacuees' departure time,a user equilibrium model of emergency evacuation route choice and departure time choice based on link transmission model is f-ormulated to assign evacuation flow to a spatio-temporal extended emergency evacuation network.After analyzing the emergency evacuation route and departure time choice model,the corresponding heuristic algorithm is designed,and furthermore an example is used to verify its effectiveness.