Drivers Rely on Place Names While Neglecting Exit Numbering in Tunnels: An Empirical Study on Information Prioritization under Cognitive Workload

The spatially constrained environment of tunnels presents significant challenges for guide sign installation, raising questions about the necessity of including exit numbering information alongside place names. This study investigates the impact of simplified tunnel exit signs on drivers’ visual recognition performance through a controlled experimental design. Three sign conditions were compared: simplified signs inside tunnels (place name only), standard exit signs inside tunnels (place name and exit numbering), and conventional signs outside tunnels (open-road baseline condition). Twenty-six licensed drivers participated in three progressive experiments focusing on information retrieval, integration, and consistency judgment. Results demonstrated that simplified signs (place name only) achieved the highest information retrieval efficiency, with significantly reduced reaction times. When place name information was sufficient, exit numbering acted as redundant cues, increasing cognitive load; incongruent number information led to significantly lower accuracy. Notably, many drivers completely ignored exit numbering information, showing significantly greater reliance on place names in tunnel environments. These findings suggest that place name-only simplified signs may improve information processing efficiency in tunnels, and motivate further validation in higher-fidelity driving contexts to inform sign design in spatially limited settings.