Hitchhiking on the digital highway: Assessing the costs and benefits of informal ridesharing

Single occupancy vehicle travel imposes many environmental and economic costs on society, and planners have acknowledged the accessibility benefits that shared mobility offers. Yet few researchers have examined automobile sharing in its most informal forms, including when people coordinate long-distance rides with strangers. To address this gap in the literature, I analyze data from posts from an online rideshare board. I focus on how the informal nature of Craigslist—a website on which people semi-anonymously post requests and offers for shared trips—presents challenges and opportunities for meeting traveler needs. After assembling data via web scraping from the Craigslist rideshare board, I examine posts using text mining and directed content analysis. Among other factors, I emphasize differences by California region, between people who offer and request rides, and between people who engage in primarily commercial versus noncommercial transactions. I find that while rideshare posters primarily listed intercity trips, regional patterns varied, and many income-seeking posters offered services within cities. While some posters mentioned social factors driving them to rideshare, economic considerations strongly motivated most posters. Finally, some posters anticipated negative aspects of informal sharing with strangers, particularly in crossing interpersonal boundaries. Together, these findings suggest gaps in the formal shared transportation system for intercity travel. To address trust and safety concerns, public ridesharing efforts should consider facilitating the exchange of personal demographic information between travelers.