Gis And Ant Colony Algorithm And Its Applied Research In The Urban Traffic Assignment

The geographic information system (Geographic Information System, refers to GIS for short) by decades of years development, specially with the fast developing of computer technology. The functions of GIS become more and more powerful and perfect, along with the GIS applied to various areas and constant deepening of it, GIS present in a period of unprecedented rapid development, GIS and people's daily life also becomes more and more closer.In traditional transportation planning, Traffic assignment was ever the last step of four phase transportation forecasting, in today's transportation planning, it is the basic theory of scheme design.The development of The optimization theory,Graph Theory,Database technology,Computer Hardware provides a solid foundation for Traffic assignment model researching. Via decades of years development, It can be said that the transportation planning in so much transportation planning problem which is researched deeply by domestic and overseas, get most research results. Shortest paths algorithms are the core algorithm of traffic assignment; moreover, optimization path analysis is the most basically function in GIS. GIS either manage spatial data and attribute data integrative , this enhance work efficiency greatly, it also can make data graphical through thematic map , so as to make data appear on map in a more intuitionistic form. Then, user can clearly see the indiscoverable mode and trend in data record, in order to provide basis for decision-making sustain. Therefore, GIS applied to traffic assignment is inevitable.The process of choose path when people travel is similar as the process of ants look for food , thereby , in this paper, try to apply Ant colony algorithm to searching optimization path , quite actually simulate the traffic travel , as to make the result of Traffic assignment more closer to reality.This paper mainly include following contents :the first chapter is introduction, introduces the disquisition research background, the GIS development and it's application general situation; the second chapter introduces basic concept about traffic assignment, Impedance function, Shortest paths algorithm and non-equilibria assignment model algorithm ; the third chapter mainly introduces the basic theory of Ant colony algorithm and it's mathematic model, at the same time improve on the pheromone of ant colony algorithm;the fourth chapter mainly introduces the road-networks's vector-graph expression and it's design for attributes database, use MapInfo building topology relationship between sections of a highways and nodes. Unite the MapX control under VB programme , carry out table of each node's adjoin point auto creating and storage, also realize road-et topology error checking;the fifth chapter include Dijkstra arithmetic and the ant colony algorithm used in searching and showing the shortest path in the road-networks, use ant colony algorithm parameter setting to analysis the effect of result; the sixth chapter realizes non-equilibria assignment model algorithm, use All-Or-Nothing method and the Increment Assignment method to assign OD quantity , the assignment result is shown in form of thematic map and export. The seventh chapter is summarize , including the article' results and shortage , And proposed future research directions.