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California Panel Study of Emerging Transportation Trends

Principal Investigator

Giovanni Circella


Farzad Alemi, Susan Handy, Patricia Mokhtarian, Lew Fulton


The study received funding by the National Center for Sustainable Transportation and Caltrans. Additional funding was provided by the STEPS Consortium.


The California Panel Study of Emerging Transportation Trends investigates the evolution of travel patterns and the adoption of new transportation technologies in California. The project was launched in 2015, and a new round of data collection was carried out in 2018. The multiple rounds of surveys collect information on individual attitudes and lifestyles, residential location, vehicle ownership, travel behavior, the adoption of shared mobility services, propensity to use autonomous vehicles, and the plans to purchase/change a vehicle in the household. This panel study improves the understanding of the impacts of emerging technologies and shared mobility services, including ridehailing (e.g., Uber and Lyft) and pooled ridehailing services (e.g., UberPOOL and Lyft Line), on vehicle ownership and travel behavior, e.g., the use of other travel modes, while controlling for other changes in transportation trends in California through the application of a unique longitudinal approach.




Matson G., McElroy s., Lee Y., and Circella G. Longitudinal Analysis of COVID-19 Impacts on Mobility: An Early Snapshot of the Emerging  Changes in Travel Behavior. (Under review at TRR)


Alemi, F., G. Circella, P. L. Mokhtarian and S. L. Handy (2019) “What Drives the Use of Ridehailing in California? Ordered Probit Models of the Usage Frequency of Uber and Lyft”, Transportation Research Part C, 102, 233-248. (JOURNAL ARTICLE)

2019 Lee, Y., G. Circella, P. L. Mokhtarian and S. Guhathakurta (forthcoming) “Are Millennials More Multimodal? A Latent Class Analysis with Attitudes and Preferences”, Transportation (accepted). (JOURNAL ARTICLE)
2018 Alemi, Farzad, Giovanni Circella, Patricia Mokhtarian, and Susan Handy. “Exploring the latent constructs behind the use of ridehailing in California.” Journal of choice modeling 29 (2018): 47-62. (JOURNAL ARTICLE)

Alemi, Farzad, Giovanni Circella, Susan Handy, and Patricia Mokhtarian. “What influences travelers to use Uber? Exploring the factors affecting the adoption of on-demand ride services in California.” Travel Behaviour and Society 13 (2018): 88-104. (JOURNAL ARTICLE)


Circella, Giovanni, and Farzad Alemi. “Transport Policy in the Era of Ridehailing and Other Disruptive Transportation Technologies.” In Advances in Transport Policy and Planning, vol. 1, pp. 119-144. Academic Press, 2018. (BOOK CHAPTER)