题目：地铁网络可达性对地铁车站客流量的边际效应递减的证据

Title: Evidence of Diminishing Marginal Effect of Network Accessibility on Station-Level Rail Transit Ridership

报告人：香港浸会大学地理系王冬根教授

Speaker: Professor Donggen Wang, Department of Geography, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, China

时间：5月21日16:00

Time: 16:00, 21 May 2026

地点：51吃瓜网 渭水校区51吃瓜网 637会议室

Location: Romm 637,  School of Transportation Engineerng, Chang’an University - Weishui Campus

摘要：可达性研究通常认为网络（或区域/节点）可达性存在边际收益递减：随着可达机会数量的增加，获得机会所带来的额外收益趋于下降。基于这一理念，可以合理地假设地铁网络可达性与地铁车站交通客流之间存在非线性、具有阈值的关系。本研究以中国成都为案例对该假设进行实证检验。借助移动电话数据，分析就业岗位的空间分布，并将网络可达性界定为：从给定车站出发，通过轨道交通网络在平均通勤时间内可到达的就业岗位数量。采用广义加性模型，本研究在控制客流的空间趋势及一组协变量的情况下，灵活估计网络可达性与车站层面轨道交通客流之间的关联。此外，使用可解释机器学习技术开展稳健性检验。结果显示，尽管网络可达性总体上与车站层面轨道交通客流正相关，但这种关联会随着网络可达性的提高而逐渐减弱；当网络可达性超过170万这一阈值后，关联趋于平缓并在统计上不再显著。低于该阈值的车站全部位于轨道交通网络的边缘，表明对这些车站实施有针对性的网络可达性提升措施有望带来显著的客流增量。这些发现为网络可达性边际收益递减这一概念提供了直接的实证支持，并有助于更细致地理解车站层面轨道交通客流如何响应网络可达性变化。

Abstract: Accessibility research posits diminishing marginal returns to network (or regional/nodal) accessibility: the additional benefit from access to opportunities tends to decline as the number of reachable opportunities increases. Building on this idea, it is reasonable to hypothesize a non-linear, threshold relationship between network accessibility and transit ridership at the station level. This study empirically tests this hypothesis using Chengdu, China, as a case study. Leveraging mobile phone data, we map the spatial distribution of jobs and define network accessibility as the number of jobs reachable within the mean rail transit commuting time from a given station via the rail transit network. We employ a generalized additive model to flexibly estimate the association between network accessibility and station-level rail transit ridership while controlling for spatial trends in ridership and a set of covariates. Additionally, we use explainable machine learning techniques as robustness checks. Results show that while network accessibility is generally positively associated with station-level rail transit ridership, this association gradually weakens as network accessibility increases, eventually flattening and becoming statistically insignificant once network accessibility exceeds a threshold of 1.7 million. Stations below this threshold are all located on the fringes of the rail transit network, suggesting that targeted network accessibility improvements at these stations could yield meaningful ridership gains. These findings offer direct empirical support for the concept of diminishing marginal returns to network accessibility and contribute to a more nuanced understanding of how station-level rail transit ridership varies in response to changes in network accessibility.

报告人简介/Short biography

王冬根博士现为香港浸会大学地理系讲席教授，中国城市与区域研究中心主任，中国地理学会理事，行为地理专业委员会副主任，香港交通研究会理事及会士。斯坦福大学发布全球前2%顶尖学者。其主要研究兴趣包括建成环境与交通行为、气候变化、空气污染与交通韧性，城市社会空间分异、幸福感与健康地理等。王冬根教授是国际期刊《Travel Behaviour and Society》联合主编 (2013-至今)；《Journal of Transport Geography》(2013-至今), 《Transport Reviews》(2021-至今)，《The Professional Geographer 》(2024-至今)等国际期刊编委。先后主持多项香港研究资助局研究项目及中国国家自然科学基金委项目。他的最新著作发表在主要的交通、地理及城市研究的国际期刊如 Annals of the American Association of Geographers（美国地理学家协会年鉴）; Sustainable Cities and Society; Health & Place; Social Science and Medicine; Transportation Research Part A, Part E and Part D; Journal of Transport Geography; 等。