Identifying Critical Breakpoints and Latency Effects During Remote Backup Driving

As Level 4 driving automation progresses, remote driving remains a critical fallback for commercial trucks operating at the edge of their operational design domains. However, network latency presents a major challenge, impairing driving performance, increasing cognitive workload, and reducing trust in the remote driving system. This study investigates how latency affects human factors and driving performance in remote driving scenarios through a within-subject driving simulator experiment. Results showed that latency significantly increased perceived workload and reduced trust, with no direct effect on fatigue or situation awareness. Driving performance was also affected: median speed decreased, steering corrections intensified, and steering entropy increased under higher latency. Segment analysis revealed that lane-keeping tasks—particularly in curved road segments—were most sensitive to latency, exhibiting the strongest degradation in control stability. In contrast, lane-changing maneuvers were less affected, likely due to their discrete and anticipatory nature. Segmented regression identified critical latency breakpoints (347–480 ms), beyond which trust in the remote driving system and driving performance exhibited substantial changes. These findings highlight the need for latency-aware, context-sensitive design strategies, including predictive assistance, and adaptive feedback interfaces, to support safe and efficient remote truck operation under fluctuating network conditions.