孙昊
长江三角洲区域一体化如今已上升为国家战略，但是其综合交通体系尚未真正形成整体布局，各城市相对独立的布局与发展无法形成区域交通网络的合理分工，不可避免地带来了交通网络的人为割裂、资源的同质化低效竞争等问题。同时长三角城市间的交通连接效率依旧不高，部分城市间的通行时间距离较长。
因此识别长三角城市群居民城际出行的特征，发掘区域交通存在的规律和问题，最终去评价城市群内区域交通的发展水平对于发展高质量协同发展尤为重要。本研究以手机信令数据为基础，引入可达性的概念进行分析，探究如何利用手机信令数据分析长三角城市群的城际出行特征，同时如何结合城际出行数据对区域交通进行可达性评价。
首先，研究以长三角城市群41个城市2019年5月的手机信令数据为依托，根据手机定位原理结合已有研究成果，同时针对后续的研究需求，建立了一系列针对大规模手机信令数据的预处理算法，主要包括栅格法划分交通小区、数据漂移识别及处理、分箱法优化时空问题、识别停留点与出行链以及筛选跨城出行对象等，形成高质量的轨迹表、驻留表、出行表和城市栅格表等数据表。
接着，利用处理好的数据表对城市群的城际出行特征进行了完整的分析。主要包括四个方面：个体城际出行特征分析、城际出行OD分析、城际出行方式结构分析和城际出行高速通道分析。其中个体城际出行特征分析主要考虑了城际出行频次分布、城际出行时长分布和城际出发时间与到达时间分布等；城际出行OD分析利用度中心性分析了节点结构特征，选取社区发现算法分析了整体网络结构特征，利用非负矩阵分解方法分析了典型的出行需求时空模式特征；城际出行方式结构分析利用出行起讫点、最大速度、轨迹路线和交通基础设施网络等数据综合判断城际间的铁路和公路出行方式，并用出行量和分担比完成进一步分析；城际出行高速通道分析是在识别城际出行方式基础上利用轨迹进行各线路栅格的集计，进行高速通道的城际出行识别，并对高速公路进行了拥堵分析。
最后，对城市群城际公交出行可达性进行了评价。研究针对公交系统构建了多模式复合交通网络，以城际公交枢纽为着眼点，同时考虑站点的对外与对内可达性，提出新的区域可达性算法，将其分解成跨城可达性与城市内部可达性。在利用手机信令数据识别城际出行人口分布的基础上，从城市-出行者视角与栅格-出行者视角这两个视角侧重点，运用空间阻隔法分析了城市群的空间格局，同时采用双变量莫兰指数对上海市内部公交可达性与城际出行人数进行了供需匹配分析。
研究可以挖掘长三角城市群内城际出行流动的规律，解析城市群可达性的区域空间格局和供需矛盾点，发掘区域交通存在的问题，最终对于城市群交通的高质量一体化协同发展提供帮助。
关键词：手机信令数据，城市群，出行特征，可达性，供需匹配
The regional integration of the Yangtze River Delta has now become a national strategy, but its comprehensive transportation system has not yet formed an overall layout. The relatively independent layout and development of each city cannot form a reasonable division of labor in the regional transportation network, which inevitably leads to artificial segmentation of the transportation network. , homogenization of resources, inefficient competition, etc. At the same time, the traffic connection efficiency between cities in the Yangtze River Delta is still not high, and the travel time requirements between some cities are still far away.
Therefore, it is particularly important to identify the characteristics of residents' intercity travel in the Yangtze River Delta urban agglomeration, explore the laws and problems existing in regional traffic, and finally evaluate the development level of regional traffic within the urban agglomeration for the development of high-quality coordinated development. Based on mobile phone signaling data, this research introduces the concept of accessibility, and explores how to use mobile phone signaling data to analyze the intercity travel characteristics of the Yangtze River Delta urban agglomeration, and how to combine the intercity travel data to carry out regional traffic accessibility.
First of all, the research is based on the mobile phone signaling data of 41 cities in the Yangtze River Delta urban agglomeration in May 2019. According to the mobile phone positioning principle combined with the existing research results, and at the same time for the follow-up research needs, a series of large-scale data processing algorithm.is established. It mainly carried out the steps of dividing traffic cells by grid method, identifying and processing data drift, optimizing space-time problems by binning method, identifying stop points and travel chains, and screening cross-city travel objects. Finally, high-quality trajectory tables, residence tables, travel tables and city grid tables are formed.
Then, using the processed data table, a complete analysis of the intercity travel characteristics of the urban agglomeration is carried out. It mainly includes four aspects: analysis of individual travel characteristics of intercity travel crowds, OD analysis of intercity travel, structure analysis of intercity travel modes, and analysis of intercity travel expressways. Among them, the analysis of individual travel characteristics of the intercity travel crowd mainly considers indicators such as the frequency distribution of intercity travel, the distribution of intercity travel time, and the distribution of intercity departure time and arrival time; the OD analysis of intercity travel uses degree centrality to analyze the node structure characteristics. The community discovery algorithm was selected to analyze the overall network structure characteristics, and the non-negative matrix factorization method was used to analyze the typical travel demand spatiotemporal pattern characteristics; Intercity travel mode structure analysis uses data such as travel origin and destination, maximum speed, trajectory route, and transportation infrastructure network to comprehensively judge intercity rail and road travel modes, and use travel volume and sharing ratio to further conduct OD pairing and city analysis; After identifying the intercity travel mode, the analysis of the intercity expressway uses the trajectory to collect the grids of each line, completes the identification of the expressway, and analyzes the congestion of the expressway grid.
Finally, it evaluates the accessibility of intercity public transport in urban agglomerations. The research uses the public transportation system to build a multi-modal composite transportation network. Focusing on the intercity public transportation hub, and considering the external and internal accessibility of the station, a new regional accessibility algorithm is proposed. It is decomposed into cross-city accessibility and intra-city accessibility. At the same time, it can be divided into a city-traveler perspective and a grid-traveler perspective from the perspective of the difference in focus. The cumulative opportunity method and the spatial barrier method are used for evaluation, and the two methods are complementary to each other.
The study can explore the laws of intercity travel flow within the Yangtze River Delta city cluster, analyze the regional spatial pattern of city cluster accessibility and the contradictory points of supply and demand, uncover the problems of regional transportation, and ultimately provide help for the high-quality integrated and synergistic development of city cluster transportation.
Key words: mobile phone signaling data, urban agglomeration, travel characteristics, accessibility, supply and demand match
