不规则环形交叉口交通流特性研究

Study on Traffic Flow Characteristics of Irregular Roundabout

为分析环形交叉口通行拥堵问题,以大连市数码广场不规则环形交叉口为例,通过实测数据分析入口交通流的到达时空及速度分布特性,通过Fluent流体对交叉口交通拥堵情况进行模拟分析,并得到环形交叉口拥堵部位及缓解方案。研究结果表明:交叉口入口车流量与时间关系不大,与交叉口地理位置有关,其中早高峰小时入口到达和驶离车流量服从负二项分布,早高峰入口车速服从威布尔分布;环形交叉口拥堵情况多出现在交叉口出入口处,且短交织区拥堵现象较长交织区更严重。当内径由50 m增大至65 m时,交织角角度减小8°,环内压力减小25.6%,同时最小速度增大464%;当内径由65 m增大至80 m时,交织角角度减小4°,环内压力减小20.2%,同时最小速度增大62%。

In order to analyze the traffic congestion problem of roundabout,the irregular roundabout of Dalian digital square is taken as an example,the arrival time and space and velocity distribution characteristics of the entrance traffic flow are analyzed by the measured data,and the traffic congestion of the intersection is simulated and analyzed by Fluent fluid.The results show that the traffic flow at the intersection entrance has litle to do with time,and is related to the geographical location of the intersection.Among them,the arrival and departure traffic flow at the entrance of the morning peak hour obeys the negative binomial distribution,and the speed at the entrance of the morning peak hour obeys the Weibull distribution.The congestion at the roundabout mostly occurs at the entrance and exit of the intersection,and the congestion in the short weaving area is more serious than that in the long weaving area.When the inner diameter is increased from 50 m to 65 m,the weaving angle is decreased by 8°,the pressure in the ring is decreased by about 25.6%,and the minimum speed is increased by about 464%.When the inner diameter is increased from 65 m to 80 m,the weaving angle is decreased by about 4°,the pressure in the ring is decreased by 20.2%,and the minimum speed is increased by about 62%.