Impact of variable message signs on drivers' situation awareness in freeway exit areas.

• Eye movement and driving behavior were used to evaluate situation awareness (SA). • The variable message sign gives drivers a higher SA level. • The variable message signs (VMS) have a speed-limiting effect on vehicles. • Experienced drivers have better SA than inexperienced drivers. • Eye movement is a sensitive SA indicator. The driving environment in the freeway exit areas is complex, and the installation of relevant signs can enhance the creation of a safe and smooth exit area environment. This study investigated the situation awareness (SA) scores of two types of drivers using different signs in the freeway exit areas and the correlation between drivers' eye movement, driving behavior, and SA scores. The driving tasks were divided into two situations: continuing on the mainline and entering the exit ramp. The independent variables included scene type (static speed limit signs, static speed limit signs plus variable message signs, variable speed limit signs, variable speed limit signs plus variable message signs), and participant type (experienced and inexperienced participants). The dependent variables were SA, eye movement, and driving behavior. Each participant completed a driving simulation experiment with the two driving tasks, totaling eight scenes. The SA scores were measured using the Situation Awareness Global Assessment Technique (SAGAT). The driving behavior and eye movement were collected during the experimental data analysis segment, and the sensitivity indicators for evaluating drivers' SA were determined by calculating the correlation with the SAGAT scores. This paper focuses on applying variable message signs (VMS) to speed limits in freeway exit areas from the driver's perspective to enhance driving safety. The findings showed that drivers have better SA in scenes with VMS, and experienced drivers have better SA than inexperienced drivers in the same scene. The VMS affects speed control, and eye movement is a sensitive SA indicator. [ABSTRACT FROM AUTHOR]