Operations of a shared, autonomous, electric vehicle fleet: Implications of vehicle & charging infrastructure decisions
Authored by T Donna Chen, Kara M Kockelman, Josiah P Hanna
Date Published: 2016
DOI: 10.1016/j.tra.2016.08.020
Sponsors:
United States National Science Foundation (NSF)
Platforms:
No platforms listed
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Abstract
There are natural synergies between shared autonomous vehicle (AV)
fleets and electric vehicle (EV) technology, since fleets of AVs resolve
the practical limitations of today's non-autonomous EVs, including
traveler range anxiety, access to charging infrastructure, and charging
time management. Fleet-managed AVs relieve such concerns, managing range
and charging activities based on real-time trip demand and established
charging station locations, as demonstrated in this paper. This work
explores the management of a fleet of shared autonomous electric
vehicles (SAEVs) in a regional, discrete-time, agent based model. The
simulation examines the operation of SAEVs under various vehicle range
and charging infrastructure scenarios in a gridded city modeled roughly
after the densities of Austin, Texas.
Results based on 2009 NHTS trip distance and time-of-day distributions
indicate that fleet size is sensitive to battery recharge time and
vehicle range, with each 80-mile range SAEV replacing 3.7 privately
owned vehicles and each 200-mile range SAEV replacing 5.5 privately
owned vehicles, under Level II (240-volt AC) charging. With Level III
480-volt DC fast-charging infrastructure in place, these ratios rise to
5.4 vehicles for the 80-mile range SAEV and 6.8 vehicles for the
200-mile range SAEV. SAEVs can serve 96-98\% of trip requests with
average wait times between 7 and 10 minutes per trip. However, due to
the need to travel while ``empty{''} for charging and passenger pick-up, SAEV fleets are predicted to generate an additional 7.1-14.0\% of travel
miles. Financial analysis suggests that the combined cost of charging
infrastructure, vehicle capital and maintenance, electricity, insurance, and registration for a fleet of SAEVs ranges from \$0.42 to \$0.49 per
occupied mile traveled, which implies SAEV service can be offered at the
equivalent per-mile cost of private vehicle ownership for low-mileage
households, and thus be competitive with current manually-driven
carsharing services and significantly cheaper than on-demand
driver-operated transportation services. When Austin-specific trip
patterns (with more concentrated trip origins and destinations) are
introduced in a final case study, the simulation predicts a decrease in
fleet ``empty{''} vehicle-miles (down to 3-4\% of all SAEV travel) and
average wait times (ranging from 2 to 4 minutes per trip), with each
SAEV replacing 5-9 privately owned vehicles. (C) 2016 Elsevier Ltd. All
rights reserved.
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