一个改进节点生成与连接机制的城市路网生长模型

A growth model of urban road network based on improved generation and connectivity mechanism of nodes

城市路网生长模型是取得其高度非线性行为和动态进化规律,进一步提升交通管理水平实现和谐宜居家园的基础,复杂网络理论为其提供一种新方法。在采用叶脉生长模型计算各区新增节点数基础上,提出“先确定可使用土地范围,再根据距离阈值确定新增候选节点,然后基于距离成本改进竞争机制保留优胜节点”的节点生成规则;增加中介中心性约束优化连接概率函数,调整路段连接机制;选择中介中心性累计概率分布曲线斜率为路网形态结构评价指标,基于方向和度双重约束最小生成树和贪婪三角网建立改进的城市路网生长模型。以邯郸市为例的应用表明:本方法能克服模型建立时的土地利用和各区发展不均衡问题,模拟路网与实际形态结构一致,网络复杂性指标相对误差小于7%,路网动态演化规律和进化机理得到较好映射,为城市路网规划提供决策支持。

The growth model of urban road network is the basis of obtaining its highly nonlinear behavior and dynamic evolution rules,and further improving the level of traffic management to achieve a harmonious and livable home.The complex network theory provides a new method for it.Based on the number of new nodes for each district calculated by the vein growth model,the rules of node generation were proposed,where the candidate nodes are obtained on available land by the distance threshold method,and then the superior nodes are retained by the distance cost improvement competition mechanism.The connection mechanism were adjusted,where the intermediary centrality constraint is added in optimization of the connection probability function.The slope of distribution curve was used to evaluate the shape and structure of road network.Then an improved growth model of road network was established based on minimum spanning tree and greedy triangulation with dual constraints on direction and degree(DDMG).The application results in Handan City as an example show that the problems of land use and each subregion development imbalance can be overcome when the model is established,the simulated network is consistent with its actual shape and structure,and the relative errors of network complexity index are less than 7%by the proposed method.Furthermore,the dynamic evolution law and evolution mechanism of road network can be well mapped.We hope that this may provide more support in making decisions for the planning of urban road network.