城市轨道交通对居民非机动出行影响机制及影响强度的纵向实证研究

The construction of adaptive transit with urban form is gradually recognized as the key for low carbon and healthy city, it is also important to against of traffic congestion and air pollution problems. Walking and cycling are components of non-motorized travel modes. Apart from that, public transit needs walking or cycling to solve the ‘last mile’ issue, thus public transit is also an important part of the non-motorized travel. This project will report on a natural experiment in which changes to the built environment led by city-wide metro construction implemented in Nanchang, Jiangxi. Longitudinal data on built environments and non-motorized travel behaviors will be collected, one before and one after the open of metro line 1, to test the influence of transit developments, built environments on non-motorized travel behaviors. Experiment groups are from communities along the new transit line and subjects experience the built environment changes of the transit development, while, control groups are from communities away from the new transit line and subjects do not experience the built environment changes of the transit development. Previous studies testing the association between the transit developments, built environments and non-motorized travel have been largely cross-sectional and have yielded mixed results. In this project, the use of a natural experiment coupled with pre-and-post longitudinal data collection methods will provide insight into the causal relationships between the transit developments, built environment and non-motorized travel and have implications for urban planning, health, and public policy. Against the background of the lack of non-motorized travel studies in medium size Chinese cities, this project is well positioned to provide empirical evidences. Our institution and study area are in Nanchang, Jiangxi, thus the research results will provide perspectives for the new urbanization in Laoqu of China.

通过规划适应城市形态的轨道交通以望促进非机动出行，逐渐成为构建低碳城市、解决交通拥堵、促进公共健康的关键。所谓非机动出行，方式主要包括步行及自行车。另外，从广义上说公共交通也是非机动出行的组成部分，盖因公共交通起止站点均需步行或自行车接驳。本项目试图通过江西南昌市轨道交通建设的自然实验，于地铁1号线开通前后，跟踪同一批居民，收集两次纵向非机动出行及建成环境变化数据，通过设计实验组（地铁沿线社区居民，经历轨道交通变化）与控制组（非地铁沿线社区居民，未经历轨道交通变化），探索轨道交通建设对居民非机动出行的因果影响机制及影响强度。过往非机动出行的研究大多为横断面共时性探索，其结论中的影响因素常不一致，甚至互为矛盾。本项目采集纵向历时性数据，以期获得更为可靠的结论。此外，我国中小型城市的此类研究仍然十分匮乏。本项目将为我国轨道交通建设，也为老区中小型城市的新型城市化建设提供实证依据。

我国投入大量财力物力建设轨道交通，期望促进公交出行，改善城市拥堵，降低空气污染等。仅2009-2018年间，已有90多条地铁线路建成，另有多条线路已规划或在建。地铁开发伴随着大量的城市更新及土地开发，已然建设地铁即建设城市，这将改变城市发展模式，并对经济和社会产生深远影响。然而面对如此大量的地铁建设，随之而来的建成环境变化究竟对城市居民出行、健康城市及土地开发带来何种影响，目前鲜有针对性的纵向实证研究。.本项目利用城市自然实验研究，依据科学数据进行的城市轨道交通开发，可以提高地铁使用率，提升土地开发效率，从中远期上可形成以低碳出行为主的健康生活方式。研究通过江西南昌市地铁1号线所带来的城市自然实验机遇，在地铁开通前后追踪来自实验组（地铁站周边）及控制组的2000多名居民，收集各类型问卷共8000余份，行为记录4000余份。以纵向历时性非机动出行及建成环境变化数据，量化地铁建设引起的城市建成环境变化对汽车转化率、出行分担率及非机动出行行为的影响机制及影响强度。本项目依计划完成，利用城市自然实验，从三个空间尺度对新开通的地铁进行了评估：在城市尺度上，实证地铁线路的规划是否符合城市土地开发策略；在中等出行距离尺度上，实证地铁是否与其他公共交通体系整合（自行车、巴士等）；在社区尺度上，实证地铁站点是否与周边步行环境一体化建设。.项目既定目标基本完成。已经发表SSCI论文7篇（直接成果3篇，相关成果4篇），支撑4名硕士研究生完成毕业论文，进行11场国际研讨会报告研究成果。此外，拓展该研究申请了三项相关课题，并作为参与人获得2019年江西省自然科学奖。