波士顿共享单车出行与街区建成环境的关系研究——基于广义可加混合模型

共享单车作为低碳环保的交通出行方式，在全球许多城市得到了快速发展。但已有共享单车与建成环境的关系研究较少关注街区空间尺度及形态因素，且忽略了影响因素的非线性作用。基于波士顿共享单车出行数据，分析共享单车出行的时空特征；运用广义可加混合模型，解析骑行量与街区建成环境的关系。结果表明：①波士顿共享单车骑行量由中心区向城市外围呈圈层梯度递减趋势，骑行距离具有3km集中骑行圈与6km极限骑行圈特征；②周末、天气、温度等时变因素会显著影响单车使用；③骑行量与街区总人口数、路网密度和地铁接入性显著正相关，与街区路网方向熵、平均路段长度分别呈L形、倒U形的非线性关系。最后，从可骑行社区构建、TOD慢行系统建设以及精准化共享单车投放等方面，阐述了研究对我国城市的启示。

As a low-carbon and environmentally friendly travel mode, bike-sharing (BS) has developed rapidly in many cities at home and abroad. However, existing studies have paid little attention to the relationship between urban morphology factors and BS ridership, and overlooked the nonlinearity of the relationship. This study analyzes the spatio-temporal characteristics of BS trips based on Boston's BS system data. We use generalized additive mixed model (GAMM) to capture the nonlinear relationship between BS ridership and built environment characteristics. The results show that: (1) BS ridership has a spatial pattern of attenuation from the downtown area to the periphery area. BS travel distances are concentrated at 3km, with a limit of 6km. (2) Temperature, weekday, and weather have significant effects on BS ridership. (3) BS ridership is linearly and positively correlated with total population, road density and metro accessibility, and has a nonlinear relationship with street orientation entropy and average road length. Finally, we provide corresponding policy implications for China based on the empirical findings.