Primary Study On Spatial Characteristics Of Traffic Flow In Typical Area Of Beijing

In metropolitan cities, the key method to solve traffic problems is to make the road-network have the best performance, which include two meanings: one is through deeply analyzing the characteristics of traffic flow, developing the running efficiency to maximize the capacity of existing road-network; the other is through fully recognizing the timing and spatial characteristics of traffic demand, raising the service level of the whole transport system. Therefore, from the view of traffic flow running, this paper studies the relation between the urban spatial layout and the traffic flow indexes, like traffic volume and composition, and using the method of microscope traffic simulation to analyze the effect of traffic composition to road-network efficiency. The main content include the following two parts:Firstly, on practical data, from the view of space and road grade, the spatial characteristics of Beijing road traffic are analyzed. Based on the related traffic indexes, the traffic features are studied from the view of road grade, so the traffic volume and composition of different road grade within investigation area are researched; Based on the existing spatial structure in Beijing, the relation between traffic flow and spatial structure are studied. Traffic flow are distributed disproportional among the loop lines, and this difference shows great regular features based on the spatial changing in the city. In morning peak time, the average traffic volume per lane will increase when closed to the city center; in evening peak time, it has the opposite phenomena. Therefore, the tidal phenomenon is very obvious in Beijing.Secondly, for developing the whole efficiency of transport network, simulation method is used to analyze the quantificational effect of traffic composition on passenger carrying capacity. Based on simulation data of microscope traffic simulation software VISSIM, the effect of traffic composition on vehicle capacity and passenger carrying capacity is studied. The conclusions are obtained that the number of vehicle decreases with the increasing proportion of bus in traffic. And the increasing proportion of bus will lead to the increasing of passenger carrying capacity. So, improving traffic flow composition and increasing the proportion of bus or giving them priorities can achieve the goal of improving efficiency of road and relieving traffic congestion.Basing on researches above, this paper analyzes the measures about how to improve the whole traffic system operation performance on existing transport resources of Beijing. With spatial distribution characteristics of traffic composition, theadjustment measures are put forward from bus, car and other traffic methods aspects ,toachieve the balance of traffic supply and traffic demand.