Presentation given at a Department of Energy (DOE) workshop on "Shaping the Transportation Revolution" in Sacramento on October 21, 2015. Highlights trends in shared-use mobility, potential impacts of vehicle ownership, and challenges for researchers to measure the impacts of these services. Note: this work was conducted while I was a Research Scholar at Stanford University. Views are my own.

1. Vehicle ownership models:
Engaging with new technologies and
business models
Regina R. Clewlow, Ph.D.
Engineering Research Scholar
Stanford University
www.reginaclewlow.com
October 21, 2015
D E PA RTM E NT OF ENE RGY W ORK S HOP :
SHAPING THE TRANSPORTATION R EVOLUTION

2. Regina R. Clewlow, 2015
Motivation: Significant projected growth in transportation
energy use and greenhouse gas emissions
Source: IIASA Global Energy Assessment, 2012
Transportation energy and GHG
emissions are projected to
approximately double from 2010
to 2050
Light duty vehicles continue to
be the dominant source of
energy use and emissions

3. Regina R. Clewlow, 2015
Historically, the vehicle fleet has turned over slowly
Source: IIASA Global Energy Assessment, 2012
Survival Rates of Light-Duty Vehicles (LDVs)
There are many changes
afoot that could alter
historical assumptions
about vehicle utilization
and turnover

4. Regina R. Clewlow, 2015
Major shifts in the transportation sector
Connected Shared
AutomatedElectric
Mobility as a
service (not a
product)
On-demand
Operational
efficiency
Increased
accessibility
Vehicle-grid
integration
Increased
multitasking
Multimodal
Incentivize time
and mode shift
Increasing
urbanization
and EV adoption

5. Regina R. Clewlow, 2015
The evolution of shared-use mobility services
Carsharing: Private Station-Based
Ridesharing Services: TNCs
Carsharing: Peer-to-Peer
Carsharing: Private A-to-B

6. Regina R. Clewlow, 2015
The evolution of shared-use mobility services
Carsharing: Private Station-Based
Ridesharing Services: TNCs
Carsharing: Peer-to-Peer
Carsharing: Private A-to-B
Paradigm shift from vehicles
as a product
to vehicles
as a mobility service

7. Regina R. Clewlow, 2015
Carsharing 1.0 was a niche market
Estimated Consumers
Source: Shaheen & Cohen, 2013
-
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
7,000,000
8,000,000
9,000,000
Carshare Members (N.A.) Carshare Members (Global)
Uber Users (Global)
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Carshare Vehicles (N.A.) Carshare Vehicles (Global)
Uber Drivers (Global)
Estimated Vehicles/ Drivers
• “Traditional”, station-based carsharing primarily worked in major,
metropolitan areas
• Members tended to be young, highly educated, and medium to high
income (and lived in cities)
• They were also likely to be pro-environment and pro-new technology
• Less than 1% of the general population in the U.S. were members

8. Regina R. Clewlow, 2015
Ride-hailing (carsharing 2.0) is on a different trajectory
• Over the past ~15 years, services like Zipcar attracted about 1 million
users in North America, and 1.7 users globally
• Within ~5 years, Uber has attracted at least 8 million globally
• Value proposition is fairly obvious – it is much more convenient (and in
some cases cheaper) to book a ride than to use a station-based shared
vehicle
Estimated Consumers
Source: Smith, 2015
-
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
7,000,000
8,000,000
9,000,000
Carshare Members (N.A.) Carshare Members (Global)
Uber Users (Global)
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Carshare Vehicles (N.A.) Carshare Vehicles (Global)
Uber Drivers (Global)
Estimated Vehicles/ Drivers

9. Regina R. Clewlow, 2015
What do we know about the impact of carsharing on
vehicle ownership?
One study suggests that
1 station-based carsharing
vehicle can replace between 9
to 13 vehicles (Martin &
Shaheen, 2010)

10. Regina R. Clewlow, 2015
What do we know about the impact of carsharing on
vehicle ownership?
The largest claim suggests
that
1 carsharing vehicle can
replace up to 32 vehicles
(AlixPartners, 2014)

11. Regina R. Clewlow, 2015
What do we know about the impact of carsharing on
vehicle ownership?
A more recent study based
on a statistical sample of the
general population finds that
1 station-based carsharing
vehicle likely has no impact on
vehicle ownership – in the
suburbs.
However, carsharing members
do own 0.2 to 0.4 fewer
vehicles in dense, urban
neighborhoods
(Clewlow, 2015)

12. Regina R. Clewlow, 2015
Challenges of estimating the “impact” of shared mobility
on vehicle ownership
There are two factors that have a strong influence on vehicle ownership (and
VMT) that we need to account for:
1. Built environment
• People own fewer cars in dense, urban environments. Why? Various
reasons, including availability of transit and walkability.
Also, it is a lot more painful (and often expensive) to park a car in a city
• What is the “impact” of shared mobility on behavior vs. the “impact” of
urban living on vehicle ownership or VMT?
• We need better modeling efforts to inform public policy
2. Self-selection
• With earlier shared vehicle models, I suspect that adopters were likely
pro-environment, and more likely to want to give up a vehicle
• Are late-stage adopters also eager to give up their vehicles? Or adopters
of ride-hailing services?
• Currently, we don’t know

13. Regina R. Clewlow, 2015
Alternative fuel vehicle ownership is higher among
carsharing households
Vehicles of Adopter HouseholdsVehicles of Non-Adopter Households
92%
6%
0%
0%
2%
0%
Gas Hybrid PHEV EV Diesel CNG
84%
11%
1% 1%
3%
0%
Gas Hybrid PHEV EV Diesel CNG
Source: Clewlow, 2015 (based on analysis of CHTS
data)

14. Regina R. Clewlow, 2015
Alternative fuel vehicle ownership is higher among
carsharing households
Vehicles of Adopter HouseholdsVehicles of Non-Adopter Households
92%
6%
0%
0%
2%
0%
Gas Hybrid PHEV EV Diesel CNG
84%
11%
1% 1%
3%
0%
Gas Hybrid PHEV EV Diesel CNG
Source: Clewlow, 2015 (based on analysis of CHTS
data)
Carshare adopters are more likely to
own an alternative vehicle. Why? Likely
reasons:
• Pro-environmental
• Early adopters of new tech
However, perhaps exposure to
alternative vehicles through carsharing
has some incremental impact on vehicle
choice

15. Regina R. Clewlow, 2015
Auto manufacturers are placing electric vehicles in
shared fleets (for various reasons)
Ford
go!drive
Daimler car2go
BMW DriveNow Scoot Networks w/ Renault-Nissan
Twizy

16. Regina R. Clewlow, 2015
In conclusion, we need more rigorous research on the
behavioral impacts of shared mobility
• Evidence of vehicle reduction as a result of station-based
carsharing is still fairly murky
• Important to distinguish between the effect of living in a dense,
transit-rich environment vs. the effect of shared mobility (while
also accounting for self-selection issues)
• We know less about the impacts of one-way or free-floating
carsharing services
• Do they reduce vehicle ownership?
• Do they reduce VMT?
• Does exposure to electric vehicles promote purchase?
• We know even less about on-demand ride-hailing services (Uber,
Lyft)
• We need more and better data, as well as more rigorous research
methods to examine impacts on vehicle ownership and travel
behavior
• Surveys and data from shared mobility providers are useful (if
examined by an impartial researcher); however
• Statistical, representative samples of the general population are
also critical

17. Regina R. Clewlow, 2015
Despite many uncertainties, there are changes afoot
that seem likely to lead toward
• Further change in vehicle ownership models
• Higher utilization of vehicles
• Faster turnover of vehicles
There are potentially more opportunities to
accelerate the adoption of zero emission vehicles…
At least in cities.

18. Regina R. Clewlow, 2015
Thank you
Regina R. Clewlow, Ph.D.
Engineering Research Scholar
Stanford University
http://www.reginaclewlow.com
rclewlow@stanford.edu
Twitter: ReginaClewlow