Feasibility Study Of Urban Expressway Construction Project

The urban expressway provides fast cross-regional transportation links,and it is responsible for the rapid distribution of external traffic between the central city and the city.Taking Gongyebie Street as the case study,this research predicted the traffic demand,selection types and cross-cutting of the expressway,etc.,and proposed a rapid road construction plan that meets residents' travel demand.Firstly,the background and functional orientation of the project construction were analyzed.The current situation and planning of the land use,transportation facilities and rail transit along the affected area are analyzed in detail.The important road nodes on the surrounding road network were found.Data collection was carried out from the aspects of road traffic and residents' travel,and the traffic volume was divided into trend traffic volume and induced traffic volume according to the particularity of the construction project.For the trend traffic volume,the traffic generation forecast based on the generation rate method is used to obtain the recent travel and travel attraction of the residents.The double-constrained gravity model is used to predict the distribution characteristics of the residents' travel.The Logit model is used to splited the way of residents' travel;the traffic allocation of each section is determined according to the multipath probability model.For the induced traffic volume,the gravity model method was adopted,and the concept of “regional economic accessibility” was introduced.Providing a basis for the determination of the following construction plans.Then,according to the "Urban Road Design Code",the number of lanes was calculated.Through FTOPSIS fuzzy comprehensive evaluation,from four aspects of construction difficulty,project cost,economic benefit and landscape effect,the scheme comparison of the expressway type was carried out,and finally the whole line of elevated type was selected.In terms of road cross section,through analysis and comparison,the scheme of non-closed setting of bus lanes was selected,and the construction plan and cross-section design scheme of important nodes along the line were determined.Finally,based on the comparison of the advantages and disadvantages of the three methods of HCM,TRRL and Urban Road Engineering Design Specification,the HCM method combined with the predicted traffic volume is used to calculate the number of lanes,and the presence or absence of the diversion island is proposed.Two kinds of intersection channelization schemes were simulated by using Vissim in terms of traffic delay and rear-end conflict risk.The setting of the diversion island was determined as the final scheme,and the plane geometric design scheme of eachintersection was given.