As a new mode of shared mobility that allows users to share the same trip (vehicle) with others at a low travel cost, ridesplitting reduces environmental pollution and eases traffic congestion. Although the relationship between the built environment and the ridesplitting adoption rates has been explored before, few studies investigated the effect of fare discounts on the ridesplitting adoption rate (proportion of ridesplitting trips to ride-hailing trips) while controlling for the origin and destination characteristics. Thus, we explored this topic by analyzing the ride-hailing trip data of Chicago from January to May 2019. The generalized additive model was used to investigate the nonlinear impacts of built environment variables (e.g., population density and employment density) and travel attributes (fare discount and median trip distance) on ridesplitting adoption rates. One notable finding is that the fare discount is most effective in improving ridesplitting adoption rates when its value is around 0.23. In addition, because the trip fare is rounded to the nearest $2.50, a sensitivity analysis was performed to make sure that the approximation had a limited impact on the study results. Finally, the origin–destination (OD) pairs with a high potential for improving the ridesplitting adoption rate were identified. These OD pairs are the trips related to the airports and the trips from the north to downtown. The findings can help transportation planners and government agencies identify the areas for ridesplitting improvement and provide guidelines for transportation network companies to set appropriate fare discounts for ridesplitting.

拼车作为一种允许用户以较低的出行成本与他人共享同一行程（车辆）的新型共享出行模式，可以减少环境污染，缓解交通拥堵。尽管之前已经探讨了建成环境与拼车采用率之间的关系，但很少有研究在控制出发地和目的地特征的同时调查票价折扣对拼车采用率（拼车出行与网约车出行的比例）的影响。因此，我们通过分析 2019 年 1 月至 2019 年 5 月芝加哥的网约车出行数据来探索这个主题。广义加性模型用于研究建筑环境变量（例如，人口密度和就业密度）和出行属性（票价折扣和中位行程距离）对拼车采用率的影响。一项值得注意的发现是，当票价折扣的值约为 0.23 时，票价折扣在提高拼车采用率方面最为有效。此外，由于行程票价四舍五入到最接近的 2.50 美元，因此进行了敏感性分析以确保近似值对研究结果的影响有限。最后，确定了具有提高拼车采用率的高潜力的起点-终点 (OD) 对。这些 OD 对是与机场相关的行程以及从北部到市中心的行程。