As Transportation Network Companies (TNCs) have expanded their role in U.S. cities recently, their services (i.e. ridehailing) have been subject to scrutiny for displacing public transit (PT) ridership. Previous studies have attempted to classify the relationship between transit and TNCs, though analysis has been limited by a lack of granular TNC trip records, or has been conducted at aggregated scales. This study seeks to understand the TNC-PT relationship in Chicago at a spatially and temporally granular level by analyzing detailed individual trip records. An analysis framework is developed which enables TNC trips to be classified according to their potential relationship with transit: complementary (providing access to/from transit), substitutive (replacing a transit alternative), or independent (not desirably completable by transit). This framework is applied to both regular operating conditions and to early stages of the COVID-19 pandemic, to identify the TNC-PT relationship in these two contexts. We find that complementary TNC trips make up a small fraction of trips taken (approximately 2%), while potential independent trips represent 48% to 53% and potential substitution trips represent 45% to 50%. The percentage of substitution trips drops substantially following COVID-19 shutdowns (to around 14%). This may be attributed to a reduction in work-based TNC trips from Chicago's north side, indicated by changes in spatial distributions and flattening of trips occurring during peak hours. Furthermore, using spatial regression, we find that an increased tendency of TNC trips to substitute transit is related to a lower proportion of elderly people, greater proportion of peak-period TNC travel, greater transit network availability, a higher percentage of white population, and increased crime rates. Our findings identify spatial and temporal trends in the tendency to use TNC services in place of public transit, and thus have potential policy implications for transit management, such as spatially targeted service improvements and safety measures to reduce the possibility of public transit being substituted by TNC services.

由于交通网络公司 (TNC) 最近扩大了它们在美国城市中的作用，它们的服务（即叫车服务）因取代公共交通 (PT) 乘客而受到审查。以前的研究试图对公交和跨国公司之间的关系进行分类，但分析受到缺乏详细的跨国公司出行记录的限制，或者是在聚合尺度上进行的。本研究旨在通过分析详细的个人旅行记录，在时空粒度级别上了解芝加哥的 TNC-PT 关系。开发了一个分析框架，使 TNC 旅行能够根据其与公共交通的潜在关系进行分类：互补（提供进出公共交通的通道）、替代（替代公共交通）或独立（不希望通过公共交通完成）。该框架适用于常规操作条件和 COVID-19 大流行的早期阶段，以确定这两种情况下的 TNC-PT 关系。我们发现补充 TNC 旅行只占旅行的一小部分（大约 2%），而潜在的独立旅行占 48% 到 53%，潜在的替代旅行占 45% 到 50%。在 COVID-19 关闭后，替代行程的百分比大幅下降（降至 14% 左右）。这可能是由于芝加哥北侧以工作为基础的跨国公司出行减少，这表现为空间分布的变化和高峰时段出行的扁平化。此外，使用空间回归，我们发现跨国公司出行替代交通的趋势增加与老年人比例较低有关，高峰期跨国公司旅行的比例更大，公交网络的可用性更高，白人人口的比例更高，犯罪率更高。我们的研究结果确定了使用 TNC 服务代替公共交通的趋势的空间和时间趋势，因此对交通管理具有潜在的政策影响，例如空间有针对性的服务改进和安全措施，以减少公共交通被 TNC 取代的可能性服务。