
10
Discussion Paper
Driving the Future: How Connected Autonomous Vehicles Reshape Travel and Energy Demand in Urban
and Rural Areas – An Empirical Modeling Approach
Income levels also play a role in travel behavior and VMT.
Higher incomes facilitate greater vehicle ownership and support
discretionary travel, resulting in increased VMT (Federal
Highway Administration 2018). In contrast, economic downturns
or recessions reduce disposable incomes, often resulting in
decreased travel activity. For instance, during the 2007-2009
recession in the United States, there was a notable decline in
auto output’s share of gross domestic product (GDP), reflecting
reduced travel activity amid economic hardships (Samaddar and
Bachman 2022). These shifts underscore the sensitivity of VMT
to economic conditions and the affordability of travel.
As these traditional factors continue to influence VMT dynamics,
emerging technologies are poised to redefine the transportation
landscape. Among these, CAV technology stands out as a trans-
formative force, ushering in a new era of mobility. By integrating
advanced communication systems and autonomous capabilities,
CAVs promise to enhance mobility, safety, and convenience.
However, they also introduce uncertainties, particularly
regarding their potential impacts on energy demand, travel
patterns, and environmental outcomes.
2.2 Influence of Connected
Autonomous Vehicles on VMT
Determinants
The implications of CAV adoption on VMT, travel behavior, and
urban planning warrant closer examination as we consider the
future of transportation systems. CAVs are expected to signif-
icantly influence VMT trends due to their convenience, acces-
sibility, and operational flexibility. One of the primary drivers of
increased VMT is the reduction in travel effort and time costs.
With CAVs taking over the driving task, passengers can travel
more comfortably, which may lead to an increase in discre-
tionary travel (Milakis et al. 2017). Additionally, CAVs provide
mobility opportunities for previously underserved populations,
including the elderly and disabled, further contributing to
higher VMT (Martínez-Buelvas et al. 2022).
Another critical factor is the emergence of empty vehicle
travel. Unlike traditional vehicles, CAVs may undertake trips
without passengers, such as returning home after dropping
someone off or repositioning themselves to a different
location. This phenomenon poses unique challenges to VMT
management, as these empty trips add to overall road usage
and congestion (Zhang and Guhathakurta 2017). To mitigate
these effects, policymakers should consider implementing
strategies such as dynamic pricing or operational restrictions
on empty (unoccupied) vehicle movements (Fagnant
and Kockelman 2015).
CAVs hold the promise of improving fuel efficiency through
optimized driving patterns. By leveraging advanced algorithms
and communication technologies, these vehicles can achieve
smoother acceleration and deceleration, reduce idling times,
and select energy-efficient routes (Taiebat, Stolper, and Xu
2018). Such improvements could contribute to substantial
energy savings and reduced emissions. However, these
benefits must be weighed against potential energy trade-offs.
The anticipated rise in VMT due to CAV adoption could offset
gains in fuel efficiency, leading to increased overall energy
consumption. This necessitates the implementation of robust
energy policies, such as integrating renewable energy sources
for electric CAVs or encouraging energy-efficient vehicle
designs (Taiebat et al. 2019). Balancing these trade-offs will
be essential to ensuring that the environmental benefits of
CAVs are fully realized.
Beyond energy considerations, the shift in driving responsi-
bilities from individuals to CAV systems is likely to transform
travel behavior and perceptions of time costs. Freed from the
need to actively drive, passengers can repurpose travel time
for work, leisure, or other productive activities. This reduction
in the perceived cost of travel could make longer trips more
acceptable and desirable to travelers (Cohen and Hopkins 2018;
Yueshuai He, Jiang, and Ma 2022).
This behavioral shift, along with the expansion of Trans-
portation Network Companies (TNCs), such as Uber and Lyft,
is expected to impact VMT with the anticipated adoption of
autonomous vehicles (Martin, Shaheen, and Wolfe 2024;
Choi, Guhathakurta, and Pande 2022). By offering convenient,
affordable, and accessible travel options, TNCs reduce the
effort and cost associated with transportation, making
travel more appealing and less burdensome. This increased
convenience could lower the perceived value of travel time,
potentially leading to a rise in VMT (Clewlow and Mishra
2017). As CAVs become more integrated into transportation
systems in the coming decades, they are expected to play a
pivotal yet disruptive role in reshaping transportation markets
and influencing traveler behavior (Cohen and Hopkins 2018;
Garikapati and Shetiya 2024).