Exploring the Relationship between Ridesharing and Public Transit Use in the United States

Abstract

Car travel accounts for the largest share of transportation-related greenhouse gas emissions in the United States (U.S.), leading to serious air pollution and negative health effects; approximately 76.3% of car trips are single-occupant. To reduce the negative externalities of cars, ridesharing and public transit are advocated as cost-effective and more environmentally sustainable alternatives. A better understanding of individuals’ uses of these two transport modes and their relationship is important for transport operators and policymakers; however, it is not well understood how ridesharing use is associated with public transit use. The objective of this study is to examine the relationships between the frequency and probability of ridesharing use and the frequency of public transit use in the U.S. Zero-inflated negative binomial regression models were employed to investigate the associations between these two modes, utilizing individual-level travel frequency data from the 2017 National Household Travel Survey. The survey data report the number of times the respondent had used ridesharing and public transit in the past 30 days. The results show that, generally, a one-unit increase in public transit use is significantly positively related to a 1.2% increase in the monthly frequency of ridesharing use and a 5.7% increase in the probability of ridesharing use. Additionally, the positive relationship between ridesharing and public transit use was more pronounced for people who live in areas with a high population density or in households with fewer vehicles. These findings highlight the potential for integrating public transit and ridesharing systems to provide easier multimodal transportation, promote the use of both modes, and enhance sustainable mobility, which are beneficial for the environment and public health.

Do transportation network companies increase or decrease transit ridership? Empirical evidence from San Francisco

“…TNC trips concentrate in city centers where transit ridership is highest (Schaller 2018;Feigon and Murphy 2018;Fehr and Peers 2019), and in the biggest cities during peak travel times (Gehrke et al 2018;San Francisco County Transportation Authority 2017). The same travelers often make trips by both transit and TNC (Feigon and Murphy 2016;Zhang and Zhang 2018). These relationships do not establish either complementarity or competition.…”

“…The remaining studies that suggest that TNCs increase transit ridership do so based on the observations that TNC trips are made close to transit stops, or that the same individuals make both TNC trips and transit trips Murphy 2016, 2018;Rayle et al 2016;Zhang and Zhang 2018). That is flawed logic, because the same observations-TNC and transit trips proximate in location and made by the same people-may also lead to higher substitution.…”

The impact of Uber and Lyft on vehicle ownership, fuel economy, and transit across U.S. cities

“…The effects of TNCs on public transit ridership are similarly equivocal, with several survey-based studies finding ridesourcing can either replace transit ( Rayle et al., 2016 ) or complement it ( Yan et al., 2018 ; Zhang and Zhang, 2018 ; Hall et al., 2018 ) as an effective extension of an otherwise fixed network (several working papers also suggest replacement ( Alemi et al., 2018b ; Norris and Xiong, 2019 ; Manville et al., 2018 ) or complementarity ( Feigon and Murphy, 2016 ; Schweiterman and Livingston, 2018 )). Importantly, two of these previous studies report heterogeneous effects—a more positive transit correlation is found either (1) in bigger cities as well as cities with smaller transit agencies ( Hall et al., 2018 ) or (2) as a function of high population density and households with fewer vehicles ( Zhang and Zhang, 2018 )—and a working paper finds commuter rail usage increases while city bus usage declines, on average, with variation in effects across cities ( Babar and Burtch, 2017 ).…”

Does Adoption of Ridehailing Result in More Frequent Sustainable Mobility Choices? An Investigation Based on the National Household Travel Survey (NHTS) 2017 Data

“…Additionally, in this research, the possibility of reverse causality was not accounted for. A number of studies have found that people who use public transit and belong to households with a lower number of vehicles are more likely to adopt ridehailing [68][69][70]. Although no study conducted so far has confirmed the causal direction, failing to account for the possibility of reverse causality further complicates the making of any causal inferences from the findings of this research.…”