“Self-driving” or fully automated vehicles (AVs) will likely have major, though largely unpredictable, effects on transportation in the coming years. Meanwhile, transportation agencies need to plan infrastructure projects that will endure 30 years or more. To address this need, travel demand modeling experts from around the United States and Europe met at UC Davis on April 29–30, with a focus on how to update travel demand forecasting tools to accommodate AVs and other disruptive technologies (including shared mobility and alternative-fuel vehicles).
This “AV Modeling Expert Group Meeting” was hosted by UC Davis researchers in the 3 Revolutions Future Mobility Program of ITS-Davis. The meeting was funded in part by the California Air Resources Board (CARB), which is concerned with the potential impacts of AVs on energy consumption and greenhouse gas emissions.
The meeting included approximately 50 researchers and practitioners—i.e., researchers who develop new transportation models and study travel behavior, and practitioners who use transportation models to inform planning decisions. The participants came from academic institutions, state and federal agencies, U.S. Department of Energy National Laboratories, metropolitan planning organizations, and selected consulting firms.
The meeting organizer and director of the 3 Revolutions Future Mobility Program, Dr. Giovanni Circella, said, “Within the larger aim of updating forecasting models, we discussed expected impacts of AVs on roadway capacity, value of travel time, travelers’ activity patterns, household interactions, mode choice, vehicle ownership, and residential location.”
Until recently, models have relied on information from current transportation conditions and historical data to forecast travel demand with some reliability. “However, current models were not designed to and are not able to predict the impacts of emerging technologies, like shared mobility and electric vehicles, or technologies not yet in the market, like automated vehicles,” explained Dr. Circella . As a result, modelers are experimenting by testing assumptions—for example, about the percentage of AVs that will be on the road, or the degree to which people may change their travel patterns with the emergence of AVs. “The aim of this meeting and our ongoing work is to help agencies adopt modeling assumptions that are based on state-of-the-art research and the best experiences of practitioners.”
The 3 Revolutions Future Mobility Program will incorporate the findings from the meeting in an upcoming white paper on modeling the impacts of AVs on travel demand, which will be available to the public this summer. The output from the workshop will also support the modeling work that the research team will conduct during the upcoming stages of an ongoing project for CARB.