Traffic microcirculation elements table.

The built environment is an important determinant of travel demand and mode choice. Studying the relationship between the built environment and transportation usage can support and assist traffic policy interventions. Previous studies often assumed that this relationship is linear; however, the impact of the built environment on non-motorized travel efficiency may be more complex than the typically modeled linear relationships. This paper focuses on the core area of Chengguan District in Lanzhou City, utilizing multi-source big data including POI, OpenStreetMap, street view images, and built environment data. Using ArcGIS spatial analysis tools combined with the Extreme Gradient Boosting (XGBoost) model, we analyze the non-linear influence mechanisms and threshold effects of the built environment on non-motorized travel efficiency and establish a ranking of the relative importance of all built environment factors. The results indicate that factors such as the branch road/street, land-use mix, land-use density, neighborhood entrance/exit density, bus station density, and dead-end-roads density are key influences on non-motorized travel efficiency. Additionally, based on the non-linear thresholds presented in the partial dependence plots for built environment factors, this paper proposes optimization strategies for small-scale road network patterns, mixed land use, and bus-friendly environments, providing effective threshold ranges and decision-making references for urban planning and traffic management.建成环境（built environment）是影响出行需求与出行方式选择的重要决定因素。探究建成环境与交通出行行为之间的关联，可为交通政策制定与干预提供有力支撑。过往研究通常假设二者间的关联呈线性特征，但建成环境对非机动化出行效率的影响，或许比典型建模中的线性关系更为复杂。本研究以兰州市城关区核心区域为研究对象，采用多源大数据，包括兴趣点（Point of Interest, POI）、开放街道地图（OpenStreetMap）、街景影像以及建成环境数据。借助ArcGIS空间分析工具结合极限梯度提升（Extreme Gradient Boosting, XGBoost）模型，本研究分析了建成环境对非机动化出行效率的非线性影响机制与门槛效应，并构建了所有建成环境影响因子的相对重要性排序。研究结果显示，支路密度、土地混合利用度、土地开发密度、社区出入口密度、公交站点密度以及断头路密度等因子，是影响非机动化出行效率的关键因素。此外，基于建成环境因子偏依赖图所呈现的非线性门槛特征，本研究针对小尺度道路网络格局、土地混合利用以及公交友好型环境提出优化策略，可为城市规划与交通管理提供切实可行的门槛区间与决策参考。