Effect of Traffic Sign’s Information Supply Speed on Driver Performance at Tunnel Entrances

Abstract

The entrance zones of highway tunnels present a visually complex environment, often requiring multiple traffic signs to ensure driving safety. However, excessive information or improperly positioned traffic signs may cause cognitive overload, hinder their ability to adapt to changing driving conditions and compromise traffic safety. This study aims to assess the effect of traffic signs information supply speed (TSISS), which considers factors such as traffic sign information (TSI), combined installation and spacing of traffic signs, and speed limits on the road, on driving performance and CL. The study collected four types of performance data: eye movement, electroencephalogram (EEG), driving behavior, and subjective cognitive load (SCL). A driving simulator experiment used six TSISSs at the highway tunnel entrance zone: 0.333, 0.400, 0.500, 0.600, 0.667, and 0.833 items/s. An “item” is an independent directive or command of traffic signs. The results showed that as the TSISS increased, pupil area, scan rate, θ wave absolute power, longitudinal acceleration, steering wheel angle, and SCL significantly increased. In contrast, blink frequency, α wave absolute power, and vehicle longitudinal speed decreased. When the TSISS did not exceed 0.600 items/s, the efficiency values calculated by the data envelopment analysis model were high (more than 0.950). However, when the TSISS exceeded 0.600 items/s, the efficiency significantly decreased (below 0.850). Based on these findings, 0.600 items/s is recommended as the optimal threshold for TSISS at highway tunnel entrances. These findings can help evaluate the rationality and effectiveness of traffic sign placement at tunnel entrances, providing essential theoretical bases and practical guidelines for optimizing the overall design of highway traffic signs.