Effects of Video Quality on Perception and Reaction Time in Video-based Remote Train Control

Abstract

High grades of railway automation feature autonomous and automatic train service in combination with human remote control and recovery in cases of disruptions. For human remote control, video footage is a crucial information source and questions what minimum video quality is required to ensure accurate visual perception arises. Research showed various factors to determine human perception of video footage, most notably frame rate and bitrate. Yet, it remains unclear, how these metrics interact and effect visual perception and subsequent reaction times. This study aimed at establishing the effects of framerate and bitrate on perception accuracy and reaction times in a choice-reaction time setting. Higher bit and frame rate were hypothesized to go along with more accurate perception and faster responses. With data collection ongoing, so far 18 participants were shown 36, 10 seconds long video sequences showing the front view from a train cab with light signals and distance markers as target stimuli. Video quality was manipulated in bitrate (24795, 6000, 1000 bps) and frame rate (25, 15, 5 fps). Participants indicated light signal colour and distance marker values. Preliminary analysis supports the hypothesized effects. A finalized analysis will be presented and implications for remote control in railway automation discussed.