Driving Through the Network: Performance and Workload Under Latency and Video Impairment
For teleoperation system designers, this work provides evidence that latency and video quality are largely independent design levers and that physiology-aware adaptation can predict overload before safety is compromised.
This study investigated the effects of network latency (100/300 ms) and video bitrate (500/2000 kbit/s) on teleoperation performance and workload in a driving simulator with 25 participants. Results showed that both factors increased operator load and modestly affected performance, with physiological measures exhibiting sub-additive interactions, while 300 ms latency with 2000 kbit/s was velocity-equivalent to a best-case baseline.
Teleoperation promises to extend the operational envelope of automated vehicles, yet it critically depends on network latency and video quality. We report a fixed-base driving-simulator study (N=25) with a 2x2 manipulation of added latency (100/300 ms) and bitrate (500/2000 kbit/s), plus a best-case baseline (0 ms added, 9000 kbit/s). We measured effective glass-to-glass (G2G) latency per condition (baseline approx. 413 ms; effective totals approx. 500-700 ms) and verified stable framerate and encoder settings. Multimodal measures covered performance (speed, steering reversals, crashes), oculomotor behavior (blink rate, fixation duration), physiology (RR interval, heart rate, skin conductance), and subjective workload. Latency and bitrate each increased operator load and modestly affected performance. Physiological measures (heart rate, RR interval) exhibited sub-additive interactions, whereas performance and oculomotor interactions were small or non-significant. Equivalence tests showed that 300 ms with 2000 kbit/s was velocity-equivalent to best-case (SESOI +/- 2 km/h), while 300 ms with 500 kbit/s was not. We argue that latency and video quality should be treated as largely independent design levers, and that physiology-aware adaptation can anticipate overload before safety is compromised.