The Influence Of Urban Road Network On The Spatial Distribution Of Traffic Noise And Planning Forecasting Research

Traffic noise has become a pollution factor that seriously affects the quality of living and life.It is necessary to pay attention to solving the problem of traffic noise pollution through urban road network planning as soon as possible.In 2016,the State Council issued the“Several Opinions on Further Strengthening the Management of Urban Planning and Construction”,proposing to establish a layout concept of"narrow roads and dense road networks"to open up"broken roads".In 2018,the"Planning and Design Standards for Urban Residential Areas"further required that by 2020,the average urban road network density should be increased by8km/km²,but there is still a big gap.Reducing the distance between roads and opening up"broken roads"is still the development trend of the road network.The implementation of this planning concept may allow traffic noise to penetrate the otherwise quiet interior of the settlement.In response to this problem,this paper develops a dynamic simulation tool for area-level noise,and studies the effects of road network density and road connectivity on the spatial distribution of noise,providing a reference for the estimation of traffic noise in urban road network planning.In order to accurately evaluate the impact of road network on traffic noise,based on the GIS platform and the traffic micro-simulation VISSIM vehicle following model,without considering the influence of buildings on the propagation of traffic noise,a dynamic simulation tool for area-level noise was developed.Obtain real-time traffic flow data,and then realize the dynamic simulation of traffic noise,obtain the continuous equivalent A sound pressure level(L_Aeq)and noise fluctuation range(L_A10-L_A90)of each sampling point,and finally complete the data presentation by the platform to obtain the noise space Distribution（5m×5m accuracy）.The actual measurement verification shows that the noise simulation error is within the range of±3d B.Aiming at the problem of road network density,two grid network models of"wide road,sparse road network"and"narrow road and dense road network"were constructed based on two different traffic flows,respectively,for comparative analysis.The study found that when the road network space changed from"sparse road network"to"dense road network",the values of L_Aeq and L_A10-L_A90 both increased,and the low traffic flow model increased more than the high traffic flow model;the increase of L_Aeq mainly occurred In the central area of the"dredging road network"block,the increase of L_A10-L_A90 mainly occurred near the adjacent roads.Aiming at the problem of urban road connectivity,a low-connectivity road network model based on Dalian’s typical road network as the prototype and a high-connectivity model after opening some"broken roads"were constructed based on two different traffic volumes,high and low.for a comparative analysis.The traffic volume of each road in the low-and high-connectivity road network models is allocated according to the ratio of the integration index in the space syntax models of the two.The study found that with the increase of road network connectivity,the L_Aeq and L_A10-L_A90 values both increased,and the high traffic flow model,compared with the low traffic flow model,increased more;and not only increased the L_A10-L_A90 in the area near the"broken road".The changes will also make the surrounding spaces L_A10-L_A90 change.In the high-traffic model,the L_A10-L_A90 changes more than the low-traffic model.Research shows that no matter the density of the road network or the increase of road connectivity,the L_Aeq and L_A10-L_A90 will increase,which is not conducive to the prevention and control of traffic noise.