California Panel Study of Emerging Transportation Trends

ca panel pic

Principal Investigator

Giovanni Circella

Additional Researchers

Farzad Alemi, Susan Handy, Patricia Mokhtarian, Lew Fulton


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.


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

Additional Resources



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)


2019 NCST webinar "The Adoption of Shared Mobility in California and Its Impacts on the Use of Other Travel Modes" (WEBINAR)
2018 View the NCST webinar “Impacts of New Mobility Services on the Use of Other Travel Modes in California” (WEBINAR)
2017 View the Caltrans Planning Horizon seminar “Adoption of Ride-hailing in California and Impacts on the Use of Other Travel Modes” (WEBINAR)  and download the slides here (SLIDES) 


2019 Panel Study of Emerging Transportation Technologies and Trends in California: Phase 2 Data Collection  (NCST REPORT)

Circella, G., Y. Lee and F. Alemi (2019) “Exploring the Relationships Among Travel Multimodality, Driving Behavior, Use of Ridehailing and Energy Consumption”, Project Report, National Center for Sustainable Transportation. University of California, Davis, January 2019 (NCST REPORT)

2018 The Adoption of Shared Mobility in California and Its Relationship with Other Components of Travel Behavior  (NCST REPORT)
2017 What Affects Millennials’ Mobility? PART II: The Impact of Residential Location, Individual Preferences and Lifestyles on Young Adults’ Travel Behavior in California  (NCST REPORT)
2016 What Affects Millennials’ Mobility? PART I: Investigating the Environmental Concerns, Lifestyles, Mobility-Related Attitudes and Adoption of Technology of Young Adults in California (NCST REPORT)


2017 The Multimodal Behavior of Millennials: Exploring Differences in Travel Choices between Young Adults and Gen Xers in California  (NCST REPORT)