Jiang Shan, Yang Yingxiang, Gupta Siddharth, Veneziano Daniele, Athavale Shounak, González Marta C
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139;
Research & Innovation Center, Ford Motor Company, Palo Alto, CA 9304;
Proc Natl Acad Sci U S A. 2016 Sep 13;113(37):E5370-8. doi: 10.1073/pnas.1524261113. Epub 2016 Aug 29.
Well-established fine-scale urban mobility models today depend on detailed but cumbersome and expensive travel surveys for their calibration. Not much is known, however, about the set of mechanisms needed to generate complete mobility profiles if only using passive datasets with mostly sparse traces of individuals. In this study, we present a mechanistic modeling framework (TimeGeo) that effectively generates urban mobility patterns with resolution of 10 min and hundreds of meters. It ties together the inference of home and work activity locations from data, with the modeling of flexible activities (e.g., other) in space and time. The temporal choices are captured by only three features: the weekly home-based tour number, the dwell rate, and the burst rate. These combined generate for each individual: (i) stay duration of activities, (ii) number of visited locations per day, and (iii) daily mobility networks. These parameters capture how an individual deviates from the circadian rhythm of the population, and generate the wide spectrum of empirically observed mobility behaviors. The spatial choices of visited locations are modeled by a rank-based exploration and preferential return (r-EPR) mechanism that incorporates space in the EPR model. Finally, we show that a hierarchical multiplicative cascade method can measure the interaction between land use and generation of trips. In this way, urban structure is directly related to the observed distance of travels. This framework allows us to fully embrace the massive amount of individual data generated by information and communication technologies (ICTs) worldwide to comprehensively model urban mobility without travel surveys.
当今成熟的精细尺度城市出行模型依赖于详细但繁琐且昂贵的出行调查来进行校准。然而,如果仅使用大多是个体稀疏轨迹的被动数据集,对于生成完整出行概况所需的一套机制,我们了解得并不多。在本研究中,我们提出了一个机制建模框架(时间地理学),它能有效生成分辨率为10分钟和数百米的城市出行模式。它将从数据中推断家庭和工作活动地点与在空间和时间上对灵活活动(例如其他活动)的建模结合在一起。时间选择仅由三个特征来捕捉:每周基于家的出行次数、停留率和突发率。这些因素综合起来为每个个体生成:(i)活动的停留持续时间,(ii)每天访问的地点数量,以及(iii)每日出行网络。这些参数捕捉了个体如何偏离人群的昼夜节律,并生成了从经验上观察到的广泛出行行为。访问地点的空间选择通过一种基于排名的探索和优先返回(r-EPR)机制进行建模,该机制将空间纳入EPR模型。最后,我们表明一种分层乘法级联方法可以衡量土地利用与出行生成之间的相互作用。通过这种方式,城市结构与观察到的出行距离直接相关。这个框架使我们能够充分利用全球信息通信技术(ICT)生成的大量个体数据,在不进行出行调查的情况下全面建模城市出行。