Setting Optimization Of Guide Signs For Traffic Hubs Under The Network Condition

With the continuous development of the city,the traffic to the transportation hub inside and outside the city is increasing rapidly,and the scale and complexity of the road network continue to increase.However,there are relatively few perfect road sign systems for transportation junction at present,and the road network level is lacking.The comprehensive consideration of the system,lack of continuity,insufficient system,and low level of intelligent informatization application.Therefore,the thesis explores and analyzes the guide signs of urban transportation junction through the research idea of net-line-point,and optimizes the setting of nO-1D transportation hub guide signs at the road network level with the help of the map API development platform.The theory and application value of The main research content includes the following points:(1)By comparing the current research status of road signs at the three levels of road network,path and node at home and abroad,the systematic research direction of network-line-point is established.It also analyzes the elements,layers,functions,basic requirements and standard specifications of the guide signs.(2)Based on the map API development platform,the road network model is established using JS language,and based on the POI "point of interest" weight theory,important nodes are selected hierarchically and the nodes are merged to remove duplicates.Based on the road network model and important nodes,with the circle layer theory and the layered zone theory as the guiding method,the algorithm flow is designed,and the road network is marked layer by layer from the bottom,middle,and high levels to form an overall guideline under the road network.The road direction marking model provides direction inspiration for the optimal path programming later,increases search accuracy and speeds up path search.(3)Optimize the setting of guide signs based on path programming.First,the idea of optimizing the content and location of important nodes with the optimal path is established.When selecting important indicators of path programming,use tomographic analysis and use five methods: root method,arithmetic average method,sum method,least square method and matlab calculation to determine the normalized index weight sequence average driving speed(0.2857)> road level(0.2262)> path distance(0.1037).On the basis of the weighted results,an objective function is established,the optimized ACO algorithm process is designed,and the optimal path programming model for nO-1D directions and signs is established.Finally,optimize the content and location of specific important nodes on the path.(4)Based on the previous research models and theories,with the help of the map API development platform,using the JS programming language to conduct model verification analysis.With Nanjing South Railway Station as the research center,the backbone road network was established,and 47 important nodes in the road network were selected;typical routes were selected,and the index parameters were input and combined with the model to obtain the optimal path of the objective function to verify the effectiveness of the model;The optimal route planning model analyzes and adjusts the road network marking direction,and determines the final road network direction marking model;finally completes the direction and distance continuity design in the content of the important node guidance sign,the specific general urban road front distance setting and the highway three Pre-announcement distance settings,etc.The full thesis is based on the network-line-point research idea,from the road network construction at the road network level,the selection of important nodes,the direction marking,to the construction of the optimal path model for the purpose of diverting and optimizing the guide signs,and finally the specific points of the important nodes And location to design.From the point to the network,from the network to the point,two-way verification,so as to achieve the optimal setting of traffic hub guidance signs under the conditions of the road network.