Online shopping has significantly increased for the past decade. As e-commerce grows and evolves since its first appearance, consumers’ shopping behaviors also change, leading to the co-evolution of people’s shopping trips and urban freight deliveries. This co-evolution has important impacts on traffic, vehicle-miles-traveled (VMT) and parking demand in the short term, and is expected to influence residential choice and land-use patterns in the long term. However, the existing studies have not examined how the relationship among shopping channels changed over time. To address this knowledge gap, this research investigated how the complex relationship between delivery and in-store shopping trips changed from when e-commerce was relatively small to a stabilized stage, i.e., from 2009 to 2017, using the National Household Travel Survey (NHTS) data. The results from path analyses showed that the relationships among delivery, non-motorized shopping trip, and motorized shopping trip significantly shifted during an eight-year period. Not only the relationship among shopping channels but also the impacts of socio-demographic factors on shopping had changed over time. Furthermore, the behavioral shift varied by income level and urban size. This research is the first attempt investigating a heterogeneous historical trend from the transportation perspective. An understanding of how the relationship has been shifted and affected by income and urban environments will provide valuable insights into proactively planning and establishing freight demand management as well as addressing the inequality issue. The lessons learned will also be of assistance to better understand how consumers will respond to the emerging freight delivery service forms (e.g., prepared meals and grocery delivery) and their impacts on both passenger and freight transportation systems.

中文翻译：

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过去和现在的购物旅行和送货：行为转变如何因收入水平和城市规模而异

过去十年，网上购物显着增加。随着电子商务自出现以来的发展和演变，消费者的购物行为也发生了变化，导致人们的购物行程和城市货运的共同演变。这种共同演化在短期内对交通、车辆行驶里程（VMT）和停车需求产生重要影响，并预计将在长期影响住宅选择和土地使用模式。然而，现有的研究并没有考察购物渠道之间的关系如何随着时间的推移而变化。为了解决这一知识差距，本研究利用全国家庭旅行调查（NHTS），调查了从电子商务相对较小的时期到稳定阶段（即从 2009 年到 2017 年），送货和店内购物旅行之间的复杂关系如何变化。 ） 数据。路径分析结果显示，配送、非机动购物出行和机动购物出行之间的关系在八年期间发生了显着变化。随着时间的推移，不仅购物渠道之间的关系发生了变化，社会人口因素对购物的影响也发生了变化。此外，行为转变因收入水平和城市规模而异。本研究是从交通角度研究异质历史趋势的首次尝试。了解收入和城市环境如何改变和影响这种关系将为主动规划和建立货运需求管理以及解决不平等问题提供宝贵的见解。吸取的经验教训也将有助于更好地了解消费者将如何应对新兴的货运服务形式（例如预制餐和杂货配送）及其对客运和货运系统的影响。