城市道路网连通性评价指标探析

Assessment of Urban Roadway Network Connectivity

道路网连通性是评价城市道路网是否合理的重要指标之一。首先,对既有城市道路网连通性评价指标"连接度指数"进行深入解读,认为其实质上反映了路网中十字形交叉口、T字形交叉口等各类型交叉口的比例关系;其次,针对该指标无法体现交叉口转向限制对路网连通性的影响,改进建立了"连通度指数"计算方法,能够较好地描述道路交叉口存在的"非完全互通立交、转向限制、单向交通"等实际交通设计和管理条件下的方向连通性。最后,针对重庆市三个典型片区进行了应用分析。

Connectivity is one of the most important indices to assess the appropriateness and efficiency of urban roadway network. By reviewing existing criteria for urban roadway network connectivity evaluation, this paper identifies that most connectivity indices in fact reflect the proportions of intersections with vari- ous layouts （e.g. four-leg and T-shape） in roadway network. Realizing the deficiency of existing indices to consider the impact of turning restrictions on roadway network connectivity, this paper proposes a new con- nectivity index, which can better reflect the directional connectivity under different traffic design and man- agement conditions, such as interchange, turning restrictions, one-way street, and etc. Finally, the paper il- lustrates the performance of the proposed index in three typical areas in Chongqing.