Investigating the Time Required by Remote Drivers to get into the Loop During Event-based Takeovers

Abstract

Future traffic is expected to be shaped by Highly Automated Vehicles (HAV; SAE Level 4), which promise a wide range of benefits. However, achieving these benefits depends on overcoming traffic situations that are beyond the current technological capabilities of HAVs. Here, one approach could be to issue a takeover request to a remote driver (RD). In these events, the RD proceeds to take over the dynamic driving task for the HAV remotely. This leads to challenges in getting the RD into a state of "being in the loop" (i.e., gaining Situation Awareness (SA) and subsequently taking control without being physically present on site). These challenges can lead to potentially safety-critical RD task performance impairments. To date, this novel challenge has been largely unexplored. To address this gap, we propose to provide the RD with information about the evolvement of the traffic situation, continuously gathered by the HAV. In addition, augmenting the video stream with sensory data could further support the RD. In an experimental user study in a simulator setting, we investigated how Lead Time supports RDs getting into the loop (i.e., to gain SA). N = 47 participants encountered typical event-based remote driving tasks displayed in an urban traffic environment. These tasks were presented with varying Lead Time and with or without Augmentation in situations with varying Situation Complexity. Results revealed an interaction between Lead Time × Situation Complexity, where additional Lead Time was especially beneficial under high Situation Complexity. Augmentation significantly improved the dependent measures, indicating its supportive role when getting into the loop. Situation Complexity negatively affected all dependent measures, indicating that RDs encounter increased challenges when getting into the loop under high complexity. Findings contribute to understanding the supportive role of supplementary Lead Time and Augmentation for RDs getting into the loop, thereby increasing the safety of event-based remote driving.