Research On Optimization Of Location Selection Of Highway Ambiguity Route Marking Stations Based On Improved Ant Colony Algorithm

With the demolition of toll stations on the provincial borders of expressways in China,the rationality of road network toll collection has become a key topic at present.In a complex expressway network with nested loops,there are multiple paths between a pair of origindestination,which creates an ambiguity path problem.In order to solve this problem,identification stations are often set up to accurately obtain vehicle path information.In the actual expressway network,either sign stations are deployed on all loop sections,causing a waste of resources,or there are insufficient sign stations,and the shortest route is used to split the tolls,resulting in unreasonable cost splitting.Therefore,this thesis will study the location optimization problem of ambiguous route sign stations in expressway network,and realize the minimum construction cost of sign stations on the basis of solving ambiguous paths.First of all,the influencing factors of the location of the sign station are analyzed,and the principles for the layout of the sign station are clarified.Secondly,a multi-objective and ambiguous route identification station location optimization model with the smallest traffic volume and the longest mileage in the section of the identification station was established.And then the solution process of the model was designed.Thirdly,the Ant Colony Optimization(ACO)is improved from the aspects of constructing feasible solutions,heuristic information,state transition rules,and pheromone update strategies.And based on the improved ACO algorithm,an optimization process for identifying station location was presented.Fourthly,through the analysis of examples,the values of parameters such as the heuristic factor and pheromone volatilization factor of the improved ACO algorithm are obtained.For different weight values in the optimization model,genetic algorithm(GA),ACO algorithm and improved ACO are respectively used to solve the optimization model.And the results show that the improved ACO algorithm has better convergence and stability than the other two algorithms.Finally,using the location optimization model of the sign station and the improved ACO algorithm,the location and layout plan of the sign station of the expressway network in the Nanjing metropolitan area was obtained.Subsequently,a redundant layout plan based on the importance of the section of the sign station was proposed,which improves the recognition reliability of the sign station.