路段U型掉头设置的适用性研究

Study on Application of U-turn in Road Section

左转是产生冲突点最多、对交叉口影响最大的一个流向。U型掉头在改善左转与进出交通对干路车流的影响方面具有较大的作用。该方式已在我国一些大、中城市干路有所应用,但并不尽如人意。该文在分析路段U型掉头设置表层原因的基础上,从路口、路段设计、过街设施配置层面阐述我国U型掉头设置的深层次原因。并对U型掉头的适用条件、掉头区的数量、计算方法展开讨论。研究认为,U型掉头是弥补路口、路段设计缺陷的有效方法,但不是常用方法;优化断面、健全路口、合理设置过街设施是道路设计需首先考虑的任务。

Left turn is the direction to cause the most conflict points of traffic and the greatest impact on road intersection.U-turn plays a larger role to reduce impact of left turn and in/out traffic on the trunk road.U-turn organization has been used in trunk roads of some medium and large cities,but is not satisfactory.Based on analysis of U-turn used in road section,the article sets forth the deep reason of U-turn used in China from the design of road intersection and road section,and the installation of crossing facilities,and discusses the adaptable condition of U-turn,number of U-turn area and calculation methods.The study shows that U-turn is an effective method to compensate the unreasonable design of road intersection and road section,but it is not the common method.It is firstly considered to optimize the road section,to perfect the road intersection and to install the reasonable crossing facilities.