This study investigates nonlinear associations between built environment (BE) attributes and commuting mode share within rail and bus rapid transit (BRT) catchment areas. Data from approximately 2,790 fixed guideway transit station areas across 34 metropolitan statistical areas in the United States were analyzed using a random forest approach. Results show nonlinear associations of the BE with mode share in transit catchment areas with substantial differences between rail and BRT catchment areas. Rail catchment areas exhibit greater sensitivity to the BE to reduce car dependency as compared to BRT stations. Moreover, polycentricity and population density at regional level are effective at reducing car dependency. We suggest that policymakers consider BE threshold effects and station types when adjusting land-use policies, e.g., in transit-oriented development. Additionally, BRT systems could be a useful alternative to rail in sprawling areas that do not have the compactness needed to support rail.

中文翻译：

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建筑环境对 BRT 和火车站周围模式共享的非线性影响

本研究调查了铁路和快速公交 (BRT) 服务区域内建筑环境 (BE) 属性与通勤模式共享之间的非线性关联。使用随机森林方法对来自美国 34 个大都市统计区域的约 2,790 个固定导轨交通车站区域的数据进行了分析。结果显示，BE 与交通服务区域中的模式共享呈非线性关联，且铁路和 BRT 服务区域之间存在显着差异。与 BRT 车站相比，铁路集水区对 BE 表现出更高的敏感性，以减少对汽车的依赖。此外，区域层面的多中心性和人口密度可以有效减少汽车依赖。我们建议政策制定者在调整土地使用政策时（例如在以交通为导向的开发中）考虑BE阈值效应和车站类型。此外，在不具备支撑铁路所需的紧凑性的广阔地区，BRT 系统可以成为铁路的有用替代方案。