中文摘要：

为获取各路段的交通流量,将路网检测器布点问题转变成寻求有向图的流控制子图的问题.首先将任意路网抽象为有向图,定义弧的度表征路段的重要性,证明完全有向回路图（CCG）的若干结论后给出CCG最小流控制子图的获取算法,同时给出有向图非回路部分的流控制子图获取方法,进而提出能在任意路网上进行检测器优化布点的完整算法.算例选取广州火车东站附近的路网,结果验证了所提出的方法的有效性.

英文摘要：

To determine the traffic flow on every road-section,we convert the road network detector layout into the flow control sub-graph（FCSG） in a directed graph.Firstly,a road network is abstracted as a directed graph,and the edge-degree measure is defined as the importance of a road-section.After proving several statements about the completely cyclic graph（CCG）,we develop an algorithm for determining the minimal FCSG from a CCG.Meanwhile,a method for determining the FCSG from an acyclic graph is also given.Finally,the integrated algorithm for determining the detector layout in the road network is put forward.A numerical example employing the road network around Guangzhou Eastern Railway Station is given to demonstrate the effectiveness of the proposed method.