不同时间间隔下的道路交通状态判别

Analysis on Road Traffic Status Discrimination at Different Time Intervals

为了提高城市道路交通状态评价结果的准确性,确定合适的交通状态评价间隔,以连续通过断面的车辆数作为划分评价时间间隔的依据,基于集对分理论建立了交通状态评价模型。首先为了提高评价模型的运行效率,在总结分析当前研究现状的基础上,提出了以通过路段断面的车辆数来划分评价时间间隔,以车辆的瞬时速度作为交通状态识别的单一指标。其次根据集对分析的原理,以集合A(实测数据)与集合B(判别指标的标准构成)构建了集对H(A,B),从同、异、反3个角度出发,建立了基于五元系数的道路交通状态评价的模型。最后为了验证模型的有效性,以西安市某路段的实测数据为例,分别利用模糊评价法和集对分析法对此路段的交通状态等级进行了判别,证明了该方法的优越性。研究发现:两种方法的评价结果基本相同,但是基于集对分析理论的交通状态评价方法对速度的变化反应更为灵敏,得到的交通状态转变曲线更为平滑,在一定程度上可以更好地反映交通状态转变的过程性和渐变性;评价时间间隔划分得越小,交通状态对速度的变化反应越灵敏;但当评价时间间隔小于1 min时,交通状态评价结果不再受时间间隔的影响。

To improve the accuracy of urban road traffic status evaluation result and determine the appropriate traffic status evaluation interval,taking the number of vehicles passing the section continuously as the basis for dividing time interval of evaluation,the traffic status evaluation model is established based on the set bisection theory.First,to improve the operating efficiency of the evaluation model,based on the summary and analysis of the current researches,it is proposed to divide the evaluation interval by the number of vehicles passing the cross-section of the section,and to take the vehicle instantaneous speed as the single indicator for traffic status discrimination.Second,according to the theory of SPA,set pair H(A,B)is formed by set A(measured data)and set B(standard composition of discrimination indicator),and a fiveelement coefficient based road traffic status evaluation model is established from the perspectives of identity,difference and reverse.Finally,to verify the effectiveness of the model,taking the measured data of a road section in Xi’an City for example,the traffic status grade of this section is discriminated by fuzzy evaluation method and SPA method respectively,which proved the superiority of this method.It is found that(1)The evaluation results of the 2 methods are basically the same,but the traffic status evaluation method based on SPA theory is more sensitive to the change of speed,the traffic status transition curve is smoother,which can better reflect the process and gradual change of the transition to a certain extent;(2)the smaller the time interval of evaluation,the more sensitive the traffic status to the speed change;(3)but when the evaluation time interval is less than 1 min,the traffic status evaluation result is no longer affected by the time interval.