Car sharing programs like Car2Go and ZipCar have quickly expanded, with the number of United States (US) users doubling every one to two years over the past decade. Such programs seek to shift personal transportation choices from an owned asset to a service used on demand. The advent of autonomous vehicles will address many current car-sharing barriers, including users’ travel to access available vehicles. This work describes the design of an agent-based model for Shared Autonomous Vehicle (SAV) operations, the results of many case study applications using this model, and the estimated environmental benefits of such settings, versus conventional vehicle ownership and use settings. The model operates by generating trips throughout a grid-based urban area, with each trip assigned an origin, destination and departure time, to mimic realistic travel profiles. A preliminary model run estimates the SAV fleet size required to reasonably service all trips. Next, the model is run over one hundred days with driverless vehicles ferrying travelers from one destination to the next. During each 5-minute interval, some unused SAVs relocate to shorten wait times for next-period travelers. Case studies vary trip generation rates, trip distribution patterns, network congestion levels, service area size, vehicle relocation strategies, and fleet size. Preliminary results indicate that each SAV can replace around eleven conventional vehicles, but adds up to 10% more travel distance than comparable non-SAV trips, resulting in overall beneficial emissions impacts, once fleet-efficiency changes and embodied versus in-use emissions are assessed.
[1]
Y Iida,et al.
Transportation Network Analysis
,
1997
.
[2]
Mikhail Chester,et al.
Life-cycle Energy and Emissions Inventories for Motorcycles, Diesel Automobiles, School Buses, Electric Buses, Chicago Rail, and New York City Rail
,
2009
.
[3]
Elliot Martin,et al.
The Impact of Carsharing on Public Transit and Non-Motorized Travel: An Exploration of North American Carsharing Survey Data
,
2011
.
[4]
D. Schrank,et al.
2012 Urban Mobility Report
,
2002
.
[5]
Daniel J. Fagnant,et al.
Preparing a Nation for Autonomous Vehicles: Opportunities, Barriers and Policy Recommendations
,
2015
.
[6]
Matthew Barth,et al.
User Behavior Evaluation of an Intelligent Shared Electric Vehicle System
,
2001
.
[7]
Jee Eun Kang,et al.
An activity-based assessment of the potential impacts of plug-in hybrid electric vehicles on energy and emissions using 1-day travel data
,
2009
.
[8]
A. Santos,et al.
Summary of Travel Trends: 2009 National Household Travel Survey
,
2011
.
[9]
P. S. Hu,et al.
Summary of Travel Trends
,
2004
.
[10]
D. Shoup.
Cruising for Parking
,
2006
.