The role of task-switching cost in remote operation of driverless vehicle fleet*

The remote operation of automated vehicles stands as a pivotal technological solution for bridging the current driving automation technology toward the realization of safe and efficient mobility services. In the context of passenger vehicles, such as driverless buses, a remote operator will need to switch attention among different vehicles and tasks, which can include both driving-related and passenger-service related tasks. The potential cost associated with such switching may impact the operator’s performance in providing effective remote support. This study aimed to investigate the effect of task-switching costs in the remote operation of automated vehicle fleet. In an experiment involving 60 participants spanning three age groups, participants were instructed to perform remote operation tasks under three task-switching conditions. The results revealed that although a constant switch between two tasks did not affect the remote operator’s performance, there was a significant slowdown when participants randomly switched between three different tasks. Furthermore, older participants reacted significantly more slowly than younger and middle-aged participants in performing the remote operation tasks. These findings emphasized the necessity of considering the time required for remote operators to shift their attention when determining an optimal human-to-vehicle ratio. Additionally, although older participants reacted more slowly in performing the operation tasks, their response accuracies were comparable to younger and middle-aged participants, indicating that they remain suited to serve as remote operators as long as their slightly slower pace is accommodated.