Multimodal Traffic Network Optimization Design For Low-mobility Individuals

Generally,low-mobility individuals,those with less access to transportation options and who are often marginalized in the social environment,can be divided into three groups: older adults,individuals with disabilities,and low-income individuals.Different low-mobility subindividuals may have different travel difficulties using different traffic modals.However,in China the low-mobility population is significant and there is no multimodal traffic network design to consider their transportation problems.Aiming at the shortcoming,this paper proposed the methodology of multimodal traffic network optimization design for low-mobility individuals: under the normal,to optimize multimodal normal traffic network,a desired objective,whose priority is to improve the efficiency of slow traffic system(the primary transportation tool of low-mobility individuals),and then to consider the efficiency of private car;under the evacuation condition,to optimize multimodal evacuation traffic network,a desired objective,whose priority is to improve the evacuation efficiency of public transportation system(the primary evacuation tool of low-mobility individuals),and then to consider the efficiency of private car evacuation and background traffic.The paper includes five parts: the analysis of transportation demands for low-mobility individuals,the design of multimodal traffic organization strategy,the design of multimodal traffic network under the normal,the design of multimodal traffic network under the evacuation condition,and case analysis.The analysis of transportation demands for low-mobility individuals is the theory bases of multimodal traffic network design.To analyze the transportation demands of low-mobility individuals in China and understand their travel problem,a methodology,which was based on three comparisons(i.e.,among different low-mobility groups,between low-mobility individuals and the general public,and comparing Chinese low-mobility individuals in China to low-mobility individuals in the western developed country),can be used to analyze the trip characteristics and accessibility of public transportation of different populations.The design of multimodal traffic organization strategy is the model guide of multimodal traffic network design.To protect daily travel and evacuation row access of low-mobility individuals,the methodologies of multimodal traffic organization strategy design under the normal and evacuation condition are proposed respectively.Under the normal,we present the design methods,applicable conditions,and implementation effects of walking,non-motorized vehicle,and public traffic organization strategy for low-mobility individuals or different low-mobility sub-individuals,according to travel behavior characteristics of low-mobility individuals.Under the evacuation condition,we present the design methods,applicable conditions,and implementation effects of transit-oriened evacuation traffic organization strategies consiedering the background traffic guided by travel behavior characteristics of lowmobility individuals.The design of multimodal traffic network under the normal aims to solve the daily travel difficulties of low-mobility individuals.To improve the efficiency of slow traffic system(the primary transportation tool of low-mobility individuals),the multimodal normal traffic network optimization design model for low-mobility individuals is built.Firstly,we optimize the transit route network using a hybrid heuristic method based on the ant colony and genetic algorithm,and assign the state traffic flows of walking,non-motorized vehicle,and private car using the method of successive weight average;then,to obtain multimodal normal traffic preliminary design solution,the feasible multimodal normal traffic organization strategies are presented according to the data obtained by the optimization and assignment;finally,we elect better strategies from feasible multimodal normal traffic organization strategies based on the tabu search algorithm,whereby get the multimodal normal traffic optimal design solution.The design of multimodal traffic network under the evacuation condition aims to solve the traffic evacuation difficulties of low-mobility individuals.To improve the evacuation efficiency of public transportation system(the primary evacuation tool of low-mobility individuals),the multimodal evacuation traffic network optimization design model for low-mobility individuals is built.Firstly,we optimize the transit evacuation route using the ant colony algorithm,and assign the dynamic evacuation traffic flows of private car using the loading method of stochastic dynamic traffic network;then,to obtain multimodal evacuation traffic preliminary design solution,the feasible multimodal evacuation traffic organization strategies are presented according to the data obtained by the optimization and assignment;finally,we elect better strategies from feasible multimodal evacuation traffic organization strategies based on the tabu search algorithm,whereby get the multimodal evacuation traffic optimal design solution.On the road network in Wenling city,case analysis validates the relative algorithms in the multimodal normal and evacuation traffic network optimization design models,respectively,and evaluates the multimodal normal and evacuation traffic network optimal solutions,whereby indicates the feasibility of the proposed model and the practicality of the proposed multimodal traffic organization strategy.