  Aiming for a society where humans and automated vehicles can coexist
cooperatively, understanding what constitutes cooperative and trustworthy
behaviour is essential to designing automated vehicle controllers that enable
the integration of highly automated vehicles into the real world. This study
investigates how merging vehicles can gain trust from human-driven vehicles in
a congested merging situation that requires explicit and implicit
communication. Specifically, this study examines how the different behaviours
of merging vehicles in the preparatory phase of the merge affect perceived
trust from the perspective of the host vehicle in the mainstream lane. The
findings suggest that transparent longitudinal positioning could improve the
chance of successful merging, and cooperative deceleration during merging
preparation could enhance the trust perceived by the host vehicle. Furthermore,
the results reveal that, in time-sensitive situations where the merging vehicle
approaches a lane closing point, prompt and decisive action of the merging
vehicle encourages establishing trust with the host vehicle; any delay or
hesitation can result in a lower level of trust. The results can provide
valuable insights towards developing collaborative automated vehicles that
improve safety and efficiency in real-world traffic situations that involve
humans.
