Optimization Of Traffic Evacuation Based On Cell Transmission Model Under The Condition Of Limited Shelter Capacity

The rapid development of urban traffic improves the overall economic level of society and provides favorable travel conditions for people’s daily life,but at the same time,the traffic environment of pedestrians is more and more complex.In recent years,with the further increase of urban population,it is not uncommon for a large number of people and vehicles to gather in a certain place in a short time.For example,all kinds of large-scale urban activities,travel of peak period and all kinds of natural disasters and emergencies,caused a series of damages to road traffic operation,road environment,social order,etc,increased urban traffic pressure and the possibility of emergencies,when it is serious,it will even endanger the property and life safety of the public.When disaster happens,effective organization method of emergency traffic evacuation can place the people waiting for evacuation in the dangerous area to the safe area quickly,so as to maximize the overall evacuation efficiency,reduce the number of injured person and loss of property,avoid secondary disasters.Under the background of urban road network,the mathematical model of emergency traffic evacuation based on Cell Transmission Model is established in this paper,use rescue buses and cars as main transportation of evacuation,subsequently,consider the parking capacity limit of evacuation terminal fully,increasing the influence of parking lot on path choice behavior in the current evacuation route guidance scheme,thus,an emergency traffic evacuation model based on CTM with parking capacity is constructed.And optimize it with Vehicle Routing Problem,study on vehicle flow mechanism in CTM network,then the traffic flow is combined by vehicles.Finally,build a complete evacuation model of mixed traffic flow.Secondly,to solve the optimal vehicle path under the conditions of this model,in this paper,Immune Genetic Algorithm is used to design an effective solution algorithm for this model,for CTM model based on evacuation endpoint capacity limitation,design a coding scheme、population initialization method,selection,cross and mutation operators that fits its characteristics,and use C++ and other computing software to solve the optimization model,to get detailed and orderly emergency traffic evacuation plan.At last,analyze the feasibility of the model through example analysis,in case analysis,fully consider he impact of setting reverse lanes and disadvantaged groups priority on analysis results,analyze and evaluate this type of transportation organization.Finally,a feasible and efficient emergency traffic evacuation plan including bus and vehicle path was obtained.