Research On The Road Space Optimization Design In Mixed Road Section Of Historic District

Historic district is an important part of city’s transportation network.With the rapid development of economic,the impact of urban traffic on historic district is also growing.In addition,it is difficult to meet the increasing traffic demands because of low level,narrow roads and lack of traffic management facilities.Most of historic district is based on ”Code for Design of Urban Roads Engineering”(CJJ37-2012)in the initial design of roads,but there are major differences between historic district and other urban areas.The traffic function and tourism cultural transmission function are not suit to road space which affect the functional realization and unique image of historic district.Therefore,this paper combines the actual research data to optimize the road space in mixed road section of historic district.First of all,this paper defined the concept of historic district,road space and the elements of road space,then summarized the existing problems in historic district.Based on this,the paper explained that the object of this article is ground road space,further discussed the relationship between lane width and speed,traffic efficiency and the number of occupying roads vehicles.A multiple regression model was used to fit the function relationships of each variables,which can provides a theoretical basis for the establishment of optimization model.Secondly,this paper analyzed the spatial characteristics of motor vehicles in mixed road section,and summarized the applicable conditions and deficiencies of Bolankerf model.Then the model parameters were re-calibrated to get the lane width calculation formulas of different cross-section roads.On the basis,a bi-level programming model was established in view of the drawbacks that traditional lane width calculation model with simple consideration of factors.The environmental protection,intensive,patency,safety and economic indicators were the up-level model goals,and the user equilibrium model was used as down-level model.Furthermore,the bi-level programming model and Bolankerf model were compared and analyzed.Further discussed the relationship between motor vehicles and slow traffic in mixed road section,including the conflicts,coordinated development strategies and the road space competition.On this basis,the travel time value was introduced and a game model was established which from the perspective of time,traffic efficiency and comfort,then the solution steps of model were given.Finally,this paper analyzed the traffic characteristics and road network characteristics of Xiangzi Temple historic district based on actual survey data.And lane width was calculated by using Bolankerf model,bi-level programming model and game model.The result shows that the models are feasible,which can provide a theoretical reference for road space optimization design of the same type historic district.