Abstract: ArcGIS technology was used to analyze the GPS data of short distance interconnection between interchanges on the expressway. The longitudinal velocity distribution characteristics of the small-interval interweaving zone and the influence of the sub-confluence zone on the main traffic flow in conclusion were researched. Firstly, the ideology of continuous segment analysis was proposed, and the range of influence of small spacing was defined by the average speed of each unit road segment and the standard deviation of each sample speed in a unit road segment. Then, GPS data with the condition of small spacing on the East Third Ring Road and Ring Expressway of Xi'an was analyzed. The results show that：within the range of exits and entrances of short distance intercommunication, the traffic flow speed is affected by the traffic volume, and the larger the traffic flow is, the smaller the traffic flow rate is; the decrease amplitude of the velocity relative to the main line is basically stable, which has little relation with the traffic volume; the influence degree of the shunt vehicle in the shunt area is greater than that of the confluence area, which is reflected in the range of the speed drop and the influence distance to the flow of main line.

Key words: traffic and transportation engineering, taxi GPS data, small spacing between interchanges, traffic characteristics

摘要： 利用ArcGIS技术对城市快速路和高速公路小间距互通上的出租车GPS数据进行分析，研究了小间距互通交织区纵向速度分布特性及分、合流区对主线交通流影响的范围。提出了划分单元路段连续分析的思想，并以各单元路段的平均速度及单元路段内各样本速度的标准差为约束条件来界定小间距互通的影响范围；在西安市东三环快速路、绕城高速上选择符合条件的小间距互通，进行出租车GPS数据分析。研究表明：小间距互通匝道出、入口范围内，交通流速度受交通量影响，交通量越大，交通流速度越小；分、合流区速度相对主线速度的下降幅度基本稳定，与交通量大小没有太大关系；分流区受分流车辆的影响程度要比合流区受合流车辆的影响程度大，影响程度体现在车速下降幅度、对主线车流的影响范围。

关键词: 交通运输工程, 出租车GPS数据, 小间距互通交织区, 交通流特性