“十四五”时期，我国已进入城镇化发展新阶段，培育现代化都市圈是推动城市群发展的重要手段。区域交通网络中的快速交通系统如高速公路和高速铁路是都市圈形成和发展的先导条件，其引发的区域非均质时空收敛效应，深刻地影响都市圈的发展空间格局，因此都市圈空间组织关系与不同交通网络层级的交互性关系亟需审视。为探究都市圈不同圈层因人口聚集与经济发展具有错位性而引起的高速公路网和铁路网密度空间差异性发展规律，本文以长三角城市群5个都市圈为例，选取区县为空间单元，基于多源数据构建城市关联强度模型，运用多维标度分析和空间距离要素识别都市圈的不同圈层边界，包括核心圈、紧密圈和规划范围边界。通过不同空间圈层的人口密度、人均产出、地均产出、高速公路网密度和铁路网密度5个主要指标挖掘社会经济发展与交通网络密度的关联规律。结果显示：都市圈各圈层存在人口聚集、经济发展不平衡的态势，“人口密度-地均产出”和“地均产出-人均产出”发展曲线分别为“S型”和“对数型”；人口密度、地均产出与高速公路网密度呈现“对数型”曲线发展规律，现状铁路网密度曲线发展规律与高速公路有较大差异；在人口密度、地均产出大于600人/km2、8 000万元/km2时出现核心圈铁路网密度不足的状况。本研究为都市圈一体化交通网络规划研究提供新角度。

During the "14th Five-Year Plan" period, China has entered a new stage of urbanization development. Cultivating modern metropolitan areas is an efficient approach to promote the development of urban agglomerations. Rapid transportation systems such as expressways and high-speed railways in the regional transportation network are the precondition for the formation and development of metropolitan areas. The regional heterogeneous spatiotemporal convergence effects caused by them profoundly affect the spatial pattern of metropolitan areas. Therefore, there is a urgent need to examine the interactive relationship between the spatial organization of metropolitan areas and different transportation network levels. In order to explore the development law of spatial variations on expressway and railway density caused by the dislocation of population aggregation and economic development in metropolitan area hierarchy, this paper constructed a city correlation strength model based on multi-source data. It took five metropolitan areas in the Yangtze River Delta urban agglomeration as examples and districts and counties as spatial units. Multidimensional scaling analysis and spatial distance elements were applied to identify the boundaries of the metropolitan area hierarchy, namely boundaries of core circle, tight circle, and planning range. Based on the five main indicators of population density, per capita GDP, land output rate, railway density, expressway density in each metropolitan area hierarchy, this paper discovered the correlation law between socioeconomic development and transportation network density. Results show that there are unbalanced population agglomeration and economic development in each circle of the metropolitan area, and the development curves of "population density-output per land" and "output per land-output per capita" are "S-shaped" and "logarithmic", respectively; the development laws of "population density-expressway density" and "land output rate-expressway density" both show a "logarithmic" curve, but those of the current railway density curves vary from those of expressway; when the population density is higher than 600 people/km2 and the land output rate is more than 80 million yuan/km2, the railway density in the core circle is insufficient. This study provides a new perspective for the research on integrated transportation network planning in the metropolitan area.