城市交通状态的空间依赖性和异质性分析

Spatial Dependence and Heterogeneity of Urban Traffic State

有关城市交通状态空间特征的研究相对匮乏。从空间角度分析城市宏观交通特征,首先,针对城市路网几何形态和交通数据的关系提出适合于城市交通数据分析的空间模型。然后,以从长期的浮动车数据中提取的路段行程速度作为描述交通状态的实验数据,分别采用空间自相关和核密度估计法定量分析路网行程速度的空间依赖性和空间异质性,并分析其在典型时段的空间分布特征。结果显示:城市交通状态的关联性在空间上随着路段间距的增长而衰减;城市交通状态的空间分布特征随时间变化,受路网结构和区域功能的影响在空间中呈现集聚特征。

Insufficient studies have been done on spatial characteristics of urban traffic state in China. To analyze macro characteristics of urban transportation from the spatial perspective, this paper first proposes a spatial model that tailors to urban transportation data analysis based on the relationship between the lay-out of urban roadway network and transportation data. Using travel speeds on roadway segments extracted from long-term floating car data to describe traffic state, the paper investigates the spatial dependence and heterogeneity of travel speeds on roadway networks based on the spatial self-correlation and kernel density estimation method, along with the spatial distribution during typical time intervals. Results show that the relevance of urban traffic state decreases as the spacing of roadway segments increases;spatial distribution of urban traffic state changes with time, showing an aggregated characteristics in space due to the impact of structure and functionality of roadway networks.