University of California Institute of Transportation Studies

Forty-three households in the Sacramento region representing diverse demographics, modal preferences, mobility barriers, and weekly vehicle miles traveled (VMT) were provided personal chauffeurs for one or two weeks to simulate travel behavior with a personally-owned, fully autonomous vehicle (AV). During the chauffeur week(s), the total number of trips increased on average by 25 percent, 85 percent of which were “zero-occupancy” (ZOV) trips (when the chauffeur is the only occupant). Average VMT for all households increased by 60 percent, over half of which came from ZOV trips. VMT increased most in households with mobility barriers and those with less auto-dependency but least in higher VMT households and families with children. Transit, ridehailing, biking, and walking trips dropped by 70 percent, 55 percent, 38 percent, and 10 percent, respectively. The results highlight how AVs can enhance mobility, but also adversely affect the transportation system.