86 PART | II ITS users
For the AV technologies market to reach a critical size, where a large number of
consumers (car owners) are ready to adopt the new technologies and make them
part of their daily experience, it is necessary to study the factors that affect user
acceptance and the beliefs and stances of people against the AV technology and
ITS (Acheampong et al., 2018; Payre, Cestac, & Delhomme, 2014).
According to several studies in the field (Milakis, Van Arem, & Van
Wee, 2017; Van Brummelen, O’Brien, Gruyer, & Najjaran, 2018), there are
many challenges for automated and connected vehicles’ technology to over-
come, especially in what drivers believe about fully or partially autonomous ve-
hicles, their interaction with them, the benefits they bring and the risks they are
hiding. The challenges refer to the level of driver's awareness at each situation,
and the human trust and acceptance to the automated decisions of the system in
all conditions. In the first case, the need for continuous monitoring negatively
affects AVs acceptance, since it decreases their main benefit that is to provide
the driver with more freedom for side tasks (Merat & Lee, 2012; Pettersson &
Karlsson, 2015). In the second case, the driver's role in emergency cases or in
extreme conditions and the degree in which the driver supervises or takes con-
trol of the vehicle when the automated system fails or cannot operate, have not
yet been defined in all scenarios (Kyriakidis et al, 2019).
The largest part of research on the acceptance of ITS from the general public
refers to automated driving (Daziano, Sarrias, & Leard, 2017) and automated
transport (Chowdhury & Ceder, 2016) as well as on the acceptability of driver
assistance systems—in general (Adell, Várhelyi, & Nilsson, 2018; Burnett &
Diels, 2018; Rahman, Lesch, Horrey, & Strawderman, 2017) or for driving un-
der specific conditions (Larue, Rakotonirainy, Haworth, & Darvell, 2015). The
results of existing surveys show that AVs are accepted to handle trivial tasks,
but for hard conditions or critical tasks, they are slowly gaining public accep-
tance. Vehicle autonomy is not acceptable in less controlled road environments
and environmental conditions, thus resulting in using lower automation levels
only despite the fact that technological advances may be one step ahead. This
still leaves space for future studies to explore what are the factors that influence
consumers’ attitudes toward autonomous driving and build on them in order to
improve people’s willingness to use AVs and increase their trust in their capa-
bilities.
7.2 Technology acceptance and related models
In order to study and improve public acceptance for automated vehicles and
associated technologies, several models have been proposed by transportation
researchers and have been evaluated on drivers, passengers and other stakehold-
ers. According to a US based survey that studied focus groups in three different
states, California in the west, Illinois in the midwest and New Jersey in the east,
(Silberg et al., 2013), drivers are positive on the use of AVs in specific driving
conditions, for example, in closed motorways or in designated lanes. According