Study On The Capacity Of Waiting-Area For Through Vehicles At Crossing Signalized Intersection

Waiting-area for through vehicles is a kind of refinement intersection reconstruction method originated from China,which only needs to divide the Waiting-area lane by channelization,advances the stop line and sets up a new signal phase for waiting-area,avoiding the high cost of the engineering transformation at the intersection.The latest data of the traffic control department indicate that the capacity of the intersections,which has set up waiting-area for through vehicles is increased by about 10%.However,most of the current researches mainly focus on the study of setting condition for waiting-area,and there are few studies on the traffic capacity of waiting-area.In this paper,the emphasis is put on the improvement of the capacity after the setting up of Waiting-area for through vehicles.First,analyzing the traffic characteristics of through-traffic flow at signalized intersection,and summarizing the conditions for setting up at signalized intersection.It is considered that phase failure is a reasonable condition for setting up waiting-area.At the same time,we conduct a field survey for crossing signalized intersections,then,we choose the four phase cross signalized intersection as the research object,and revealing the factors affecting the setting length,sequence of signal release and the difference of signal timing.Secondly,collecting the headway of straight line vehicle at signal intersection by video camera.Next,based on survey data,analyzing the difference of queued straight line vehicles after setting up waiting-area for through vehicles at running characteristics including distribution law of headway,saturation headway,saturation flow rate,start-up lost time,providing data support for capacity research.The survey results show that there is no significant change in headway distribution,saturated headway and saturated flow rate after setting up waiting-area for through vehicles,but the start-up loss time increases to a certain extent.Thirdly,based on the design of signal intersection cases,the changes of traffic capacity are analyzed in combination with simulation and model,and the results show that the traffic capacity of the lane is improved after setting up waiting-area for through vehicles,meanwhile,the effect is more obvious with the increase of the length of the waiting-area.Compared with the straight lane,the capacity improvement of shared through-right lane is more significant under the same length of waiting-area.Under the low ratio of straight driving,the capacity of shared through-right lane can obtain greater profit,after setting up waiting-area for through vehicles.Finally,comparing the difference between the calculated values of model and the simulation results to test the model,then,obtaining a new of straight lane after modifying,and the applicable conditions of capacity upgrading model shared for through-right lane.