AOI-based gaze allocation of professional bus drivers during naturalistic docking in conventional and low-floor buses

Interactions between buses and vulnerable road users are safety-relevant in urban traffic because buses operate near curbside activity, passengers, pedestrians, motorcycles, and blind-spot regions during low-speed maneuvers. This study examined AOI-based visual inspection among professional bus drivers operating conventional and low-floor buses under naturalistic urban driving conditions. A questionnaire survey of professional drivers ( N = 215) provided descriptive contextual information on exterior indirect-vision devices and scenario-specific mirror-use needs. The primary empirical component was an on-road eye-tracking experiment involving 24 professional drivers (12 per bus-type group), each of whom completed one route run containing eight consecutive bus-stop events. Six object-based areas of interest (AOIs) were evaluated during bus-stop approach and docking. Fixation count was analyzed using an event-level negative-binomial generalized linear mixed model with Driver as a random intercept and Stop ID as a fixed control term. Fixation allocation differed substantially among AOIs, and the Bus Type × AOI interaction was significant. However, no individual AOI contrast remained significant after Holm adjustment. The findings therefore indicate a difference in the overall fixation-allocation profile between the conventional- and low-floor-bus driver groups, without confirming a difference at any single AOI.