基于点、线、面层次的公路网交通运行状态评价

由于公路网是由点成线、由线成面的统一体，为了更准确地分析和改善公路网运行状态，加强公路节点、路段、路网评价之间的联系，便于确定交通拥堵产生根由并有效采取措施，建立了一种基于点、线、面层次的公路网交通运行状态的综合评价方法。在基本单元划分和指标选取方面，以交叉口、互通式立交、收费站和基本路段作为基本单元，结合交通流理论，综合考虑各基本单元的特点，分别选取对应的评价指标，以极小型指标评价法为基本原理，构建基本单元交通综合运行指数评价模型，并确定相应的分级阈值。在交通运行状态评价方面，依托专家经验的主成分分析与客观的交通量统计调查相结合的方法确定各基本评价单元的权重向量，从而构建路段运行评价模型并给出评价分级阈值，再以各等级道路拥堵程度和路网客、货运量，分别构建路网赋权矩阵或向量，从而获得路网交通综合运行指数模型并确定评价分级阈值。最后结合算例说明该评价方法的具体操作过程，通过获取的各项基本数据，从点层过渡至线层再至面层，依次计算各层交通运行指数，确定各基本单元、路段、路网分别对应的交通运行状态。研究结果表明：不同层面之间的交通运行状态存在一定的联系，不同节点和基本路段处的运行指数差异较大，路线运行指数差别也较大，从而影响路网最终的运行状态，因此，可以通过逐级评价确定交通拥堵症结所在，有针对性地采取相关改善措施。

Evaluation of Highway Network Traffic Operation State Based on Point,Line, and Area

Considering that a road network is a composite body formed by points, lines, and areas, a comprehensive evaluation method for traffic operation status of a road network was established to more accurately analyze and improve operation status, strengthen connections between road nodes, sections, and network evaluation, and determine the root cause of traffic congestion and requisite effective measures. In terms of division and index selection, intersections, interchanges, toll stations, and road sections were used as basic units. Combined with the theory of traffic flow, the characteristics of each basic unit were comprehensively considered, and the corresponding evaluation indicators were selected. Based on the principles of the extremely small index evaluation method, the basic unit traffic comprehensive operation index evaluation model was constructed, and the classification thresholds were determined. From the aspect of traffic operation status evaluation, the principal component analysis based on expert experience and objective traffic volume statistical survey methods were combined to determine the weight vectors of each evaluation unit, to construct the road segment operation evaluation model and assign grading threshold. Then, the road network weighting matrix or vector was constructed using the road congestion degree for each level and passenger and cargo volumes of the road network to obtain the road network traffic comprehensive operation index model as well as determine the grading thresholds. An example was used to illustrate the specific processes of the evaluation method; the data obtained from the point, line, and surface layers were combined to calculate the traffic operation index of each layer and subsequently determine the basic units, road segments, and complete road network. The research results show that there are relationships among the traffic states of different levels. The operation indices of different nodes and basic road sections are different, and the difference in route operation index is also large, which affects the final operation state of the road network. Therefore, it is possible to determine the location of traffic congestion by level-wise evaluation and apply targeted improvement measures.