Research And Application Of Urban Road Travel Demand Forecasting System

More and more congestions appear in China big cities, one of the ultimate resolvents is reasonable traffic planning. Travel Demand Forecasting is the core of the traffic planning as well as the basis of the road design scheme and decision-making.Relying on the "Qingdao Urban Comprehensive Traffic Planning " project, taking Qingdao Tranffic Planning as an example, as well as basing on the large scale of traffic status quo investigation, this paper establishes the Four Step Travel Demand Forecasting System. Furthermore, it puts forward the Feedback Forecasting Technique in allusion to the deficiency of flow procedure in the traditional Four Steps Travel Demand Forecasting Technology. Finally, it realizes auto-calculating of the forecasting models and flow procedure mentioned in this paper by the use of TransCAD. This technique improves the precision and facilitation of the Travel Demand Forecasting Technology and gains a favorable result in practice.The main contents of this paper are as follows:1. Erecting the Road Traffic Information Database of Qingdao in the form of Traffic Geography Information System (GIS-T) in order to improve the management modes of traditional traffic basic database;2. According to the urban traffic status quo investigation in Qingdao, Travel Demand Forecast Model system is established and the system is integrated by the use of TransCAD. Besides, important corresponding parameters such as regression equation in Trip Generation, the impendence function in Gravity Distribution Model, Volume Delay Function in Traffic Assignment, etc. are calibrated;3. In allusion to the deficiency of traditional travel demand forecasting models, it puts forward a serial of new models and arithmetic to the new-style Mode Split Forecasting models as well as the Volume Delay Function in the state of over-congestion in the road;4. Because of the deficiency of the single forecasting procedure in thetraditional Four Steps Forecasting Technology, Feedback Loop Forecasting Technology is put forward;5. It realizes auto-calculation of all models and arithmetic mentioned above besides the Feedback Loop Forecasting Technology by using GISDK Toolkits and Batch Mode in TransCAD so as to improve forecasting precision and operation briefness;6. Urban Road Travel Demand Forecasting and Simulation System is built with good precision, convenient operation interface and abundant functions. The system can be applied not only to Qingdao urban road travel forecasting, but also can be applied to other big cities in China by the set of parameter in the interface.The models and methods in this paper are brought forward in allusion to the project of Qingdao Comprehensive Traffic Planning as though, the research thought and methods adopted in the paper can be derived from the project and applied to Traffic Planning project in other big or medium cities in China independently, this paper may be used for reference to other native cities' Travel Demand Forecasting research work.