Analysis On Traffic Capacity Of Diversion Affected Area Of Multi-lane Highway

The diversion affected area of expressway is the bottleneck section of expressway.The vehicles have to change lanes in the shunting area,which leads to traffic turbulence and traffic accidents.Because of the difference of vehicle running speed and vehicle type on each lane,the traffic flow state in the diverging section is more complex.The multi-lane expressway has its unique functions because of its traffic operation,its organizational form and its maximum road capacity,compared with two-way four-lane,six-lane,etc.,the distributary area is more sensitive to the changes of facilities and vehicle composition,and the influence range is larger.In this paper,the present situation of multi-lane expressway is analyzed,and the trend that multi-lane expressway will become an important transportation artery is made clear.Secondly,the paper analyzes the running characteristics and the control measures of the vehicles in the shunting area,and further studies the route selection and Lane changing form of the vehicles in the shunting area.Through the analysis and collection of multi-lane highway actual driving under good conditions of the traffic flow of the driving behavior data.From three aspects of traffic volume,headway and speed,this paper analyzes the traffic flow characteristics of the distributary influence zone of multi-lane expressway according to the different conditions of the distributary influence zone by using the statistical data.According to the characteristics of freeway traffic function and the location of freeway traffic diversion signs,the specific geographic location of the freeway traffic diversion section in space is defined,this paper analyzes the influence of highway planning,design and operation on the traffic operation in the diffluence area under the condition of multi-lane.Then,according to the actual operation of the vehicles in the multi-lane expressway diversion section,the microscopic simulation modeling is carried out.By setting different vehicle composition and the distribution of the expected speed,and then calibrating the simulation parameters through the orthogonal test combined with the actual data,the experimental results are more real and reasonable.Finally,according to the simulation results,the maximum service traffic volume of expressway main line and exit ramp under different service levels is calculated by combining the common capacity analysis method of shunt impact zone,the traffic capacity and service level of each shuntaffected section are obtained.Based on the Vissim simulation experiment,the average delay of the area affected by vehicle shunting is calculated under different flow and shunting ratio,and the influence of traffic congestion on shunting is analyzed.