Research On Capacity Of Urban Road Network Consider Layout Concept Of Small-scale Road With Dense-network

Aiming at solving the problems from urban road network of tradition ‘wide road,sparse road network' layout,layout concept of dense-network with small-scale road has become the new tendency in China.In this context,grasping the characteristics of urban road network and calculating the road network capacity accurately are significant to estimate the road network supply capacity and targeted traffic planning and management.Therefore,this thesis considers the influence of the change of the network characteristics on the capacity of the road network under new layout concept,and constructs the vehicle capacity model for the road network under the dense-network with small-scale road layout.Firstly,the characteristics of road network under the concept of road network structure,road network density,road width,traffic organization and intersection are analyzed.Combined with coordination of road network,motorization level,traffic management,bus adaptability,pedestrian crossing demand and related planning experience,the indicators of road network under new layout concept are quantitative defined.Secondly,this thesis filters the key factors impacted on road network capacity in traffic condition through the causal chain of SD(System Dynamics)model,and analyzes the influence of matching level of road network supply,traffic demand and traffic individual path selection from the view of road network layout mechanism,traffic individual path selection process and result.The influence of the characteristics on the network capacity is simultaneously concluded.Thirdly,based on the classical idea of time and space consumption,considering the influence of the characteristics of narrow space network layout,we discuss the calculation model of time and space resource and traffic time.Then the calculation process is depicted by amending the model,which considering the service level,traffic organization,cross-sectional form,supply and demand matching level.Finally,case-study of Chenggong New District,a low-carbon demonstration area of China,is shown the results.For both before and after enhancing density,this thesis analyzes the layout characteristics of road network,calculates the capacity of road network,evaluates the effect of improvement on capacity and concludes the application prospect of this model.The proposed road network vehicle capacity model with the layout concept of dense-network with small-scale road takes full account of the new layout concept under the network characteristics and its impact on the motor vehicle capacity,and is more suitable for capacity calculation of new tendency of urban road network planning.