快速路互通立交左转定向匝道交通特性浅析

A Study of Traffic Feature of Turn-left Directional Ramp of Expressway Interchanges

立体交叉在城市交通系统中起着举足轻重的作用。通过现场观测、数据采集等方法研究位于天津快速路上津昆互通立交的左转定向匝道交通特性。分析了纵坡对不同车流速度的影响、车辆速度变化轨迹及速度与交通量分布关系,得出纵坡对货车速度的影响比平曲线大、纵坡对大中型车的影响较大等结论。对速度与延误进行了详细分析。最后,在实测数据标定基础上,通过仿真手段在拥挤条件下的分析,推荐了该匝道的通行能力值,并经过了实测饱和流量的验证。

Flyover crossing plays an important role in urban traffic system.According to site monitoring and data collection methods,etc.,the traffic feature of turn-left directional ramp is researched,being a part of Jinkun interchanges of Tianjin expressway.The influence of longitudinal slope to different traffic flow speed and the relationship of vehicle speed change track,vehicle speed and traffic flow distribution are discussed and the results show that longitudinal slope can make truck speed more obviously than horizontal curve;meanwhile,it has more influence on medium-large type vehicles.There is a detailed analysis on speed and delay.Finally,on the basis of practical data standardization and a simulation analysis under crowed condition,the traffic capacity value of this ramp is recommended,and moreover,the recommended value is tested by practical saturation flow.