Study On The Capacity Of Interchange On One Way And Two-lane Ramps In Mountain City

Due to the restrictions of complex terrain conditions,the interchange and ramp setting characteristics of mountain cities are different from plain cities.The capacity of the ramp has an important guiding significance for the interchange design,I,through the review of large number of the domestic and foreign literatures,found that at present the setting conditions of the two lane ramp and traffic capacity of the study are inadequate,and less research on the two lane ramp of interchange in mountain city.In the mountainou city of Chongqing,there are a large number of interchange one way and two-lane ramps,due to the lack of assessment of the capacity of one way and two-lane ramp,making the post operation efficiency is not ideal,based on these,this paper made a lot of analysis on one way and two-lane ramps.First of all,this paper investigated and analyzed the setting characteristics of the interchange and ramp in the mountain city,statistical carding out its characteristics,though investigation found that the one way and two-lane ramps are the most commonly used cross section of the interchange of the mountain city.Secondly,classification and definition for the one way and two-lane ramps : due to capacity and set to two lane ramp for the first class of one way and two-lane ramps,and the others for the second class,and given the cross section layout of two kinds of two lane ramps and determined the first kind of two lane ramp as the research object of this paper is more practical significance.In addition,this paper given the quantitative analysis of the two types of two lane ramp,quantitative given the first two lane ramp setting of critical traffic volume,the second two lane ramp setting critical ramp length and traffic volume,critical longitudinal slope;and established the time based on economic net benefit model,the mode provides a new research idea for the second class of one way and two-lane ramps setting conditions;and qualitative given other factors for the second class of one way and two-lane ramps settings influence.Through the field investigation of typical one way and two-lane ramps on the city of Chongqing,analysed the traffic characteristics of one way and two-lane ramp of the mountain city interchange,analysed time headway characteristics,and calculated the proposed value of the saturation average headway of different grades of two lane ramps.Finally,through the survey analysed and referenced to the domestic and foreign related research results,and given the traffic ability of the proposed value of mountain city interchange one way and two-lane ramps,calculated the two lane ramp capacity correction coefficient,and applied to the analysis and evaluation of the specific engineering cases.It is proved that the theory and method presented in this paper has the applicability and operability.Through the study of this paper can provide theoretical support for the revision of the relevant two lane ramp setting specifications of Chongqing,also hope to provide some assistance for the mountain city interchange design personnel,which has very important significance to improve the traffic condition and efficiency of the mountain city.