Operating in the Unknown – The Difference in Remote Operators' Attitudes Based on Their Knowledge of the Task at Hand

Remotely operated vehicles are predicted to bridge the gap between conventional and autonomous vehicles. However, there are still issues to address before the technology can be fully implemented on public roads. One being how the introduction of system latency affects remote operators in different driving conditions and potentially hazardous situations. In this paper, an analysis is made of the subjective rating result of four experiments (three simulator and one remotely operated vehicle experiments) where participants acted as remote operators in varied latency conditions. A total of 114 participants in three simulator experiments drove identical scenarios. Each scenario was driven with three latency conditions in experiment one and experiment three (baseline, +100ms and +200ms). Two different latency conditions (baseline and +150ms) were applied in experiment two. The latency conditions were masked for all participants, except for 26 who functioned as a control group in experiment three. Between each latency condition, rating data was collected through questionnaires regarding comfort, perceived control and realism of scenario. After the complete drive, participants were asked supplementary questions about their experience and differences between the latency conditions. In a fourth experiment, 18 participants drove a remotely operated vehicle on a track which included tasks such as line following, slalom driving, reverse parking and precision parking. Three latency conditions (baseline, +140 ms and +340 ms) were masked, and the same questionnaires were used as in the previous experiments. Rating data was compared between the experiments, as well as objective driving data collected by the simulators and the remote operation station. There seems to be a difference in attitude based on previous knowledge about the operators’ current driving conditions, though the actual driving performance is similar. I.e., unaware participants adapt their behavior to the same extent as aware participants. Unaware participants contribute any sense of difference to mental alertness, the state of the mechanical controls or a learning effect from recognizing the scenario between conditions. Aware participants contribute their performance to their ability to adapt their behavior based on the level of latency. Participants who noticed the change in latency without being told seem to have an increased sense of frustration, which shows the importance of clear and correct information to the operators. However, as the performance of the participants were deemed ‘good enough’, the main conclusion is that there is still a need for naturalistic studies concerning the use of remote operation in a real-world scenario.