The issues of housing and traffic in China's mega cities have become increasingly pressing problems, particularly for middle/low-income tenant workers. These tenants are from less advantaged socioeconomic backgrounds, which has resulted in a significant geographical separation between their workplace and their residence. Although a large number of studies have confirmed that built environment factors have a solid impact on residents’ commuting distance, few studies have investigated the mechanism underlying the nonlinear influence on middle/low-income tenants. This paper aims to provide an in-depth analysis of the key factors and nonlinear influencing mechanism of the built environment on middle/low-income tenant workers’ commuting distance by establishing a gradient-boosting decision tree model, using Beijing as an empirical case. The paper reveals three primary findings: (1) An important nonlinear relationship between the surrounding built environment and peoples’ jobs–housing spatial proximity can be observed for those middle/low-income tenant workers who use slow and public modes of commuting. Specifically, the density of public transport stations, road networks, and workplaces, and the land use mix play a dominant role. (2) A limited effect of built environment factors can be found for the same group of tenant workers who choose cars as their mode of commuting. (3) The differences in self-selected commuting modes have a significant mediating effect on the relationship between the built environment and jobs–housing situation among middle/low-income tenant workers. Given this, effective policy guidance for residents’ travel modes is necessary to optimize the built environment indicators to achieve the best effect. In addition, we should consider giving priority to the matching indicators such as land use mix and resident population density. Another possibility is to strengthen the connection to the public transport stations, which in turn can optimize the walkability in residential environments.

The unique physical characteristics and travel preferences of disabled individuals may lead to specific spatiotemporal characteristics of subway travel. This difference may also be temporally heterogeneous on holidays versus every day, and its association with the built environment may be significantly different. However, few studies have investigated such differences in depth. This study explores the differences in the spatiotemporal characteristics of subway travel for people with disabilities using subway swipe data from Wuhan, China, on the May 1 holiday and every day, and analyzes the effects of the built environment on holiday and everyday travel for people with disabilities compared to non-disabled people using XGBoost and SHAP models. The results show that compared with non-disabled people, the spatial and temporal changes of passenger flow of disabled people are less affected by holidays, and the spatial distribution of passenger flow and traveling time is reduced and contracted, respectively, based on weekdays. Second, the relative importance of each element of the built environment on metro passenger flows for the disabled and the non-disabled differed significantly, with medical facilities and network density being the most important variables for the disabled, both on holidays and weekdays. Comparatively, non-disabled people are more affected by holidays, with the highest contribution to disabled metro patronage on weekdays being made by food and beverage facilities, which changes to attractions on holidays. In addition, all built environment elements show nonlinear and significant threshold effects on disabled and non-disabled metro ridership. Finally, the built environment has an interaction effect on disabled subway passenger flow, for example, the closer to the sub-center, the higher the number of firms, the more inhibitory effect on disabled weekday and holiday subway passenger flow. The results of the study will contribute to an in-depth understanding of the spatial and temporal characteristics of metro travel for among disabled individuals, thereby developing disability-friendly measures for rail transit systems.

居住空间分异是城市内部公共资源非均衡配置的市场化表现。但长期以来，学界对租房群体租住空间居住分异关注不够。事实上，租住作为大城市外来人口与青年群体的重要居住方式，其在空间上的分异所反映出的空间剥夺、空间排斥以及不同社会经济阶层间的隔阂等问题可能会阻碍大城市公共服务均等化的推进。论文以北京市10个核心行政区作为实证案例，将各类公共服务设施按服务范围分为本地层级和区域层级，利用空间滞后模型分别分析了两个层级的公共服务供给对租房群体居住分异的影响。研究发现：① 研究范围内相当一部分街道/乡镇存在严重的居住分异。② 租金水平和租房群体居住分异在空间分布特征上显著不同。租金水平呈现由中心向外逐渐递减的圈层状分布，租房群体居住分异指数则呈“内高—中低—外高”的夹心状分布。③ 不同层级公共服务设施对于租房群体居住分异的影响存在较大差异。本地层级公共服务中，幼儿园密度、轨道站点可达性与租房群体居住分异存在负相关性，而中学密度与租房群体居住分异具有正相关性。相比之下，区域层级的体育休闲、公园广场、医疗卫生和示范性高中等4类公共服务设施密度与租房群体居住分异的关系均不显著。基于研究结论，论文针对租房群体提出了优化居住选择和公共服务供需的政策建议，为城市公共服务设施和租赁住房的空间规划合理布局提供了科学依据。