The impact of rural expressway environments: drivers' attention allocation to variable message signs.

Variable Message Signs (VMS) are implemented at varying locations of the expressway. In this study, we compared the drivers' attention allocation to a 'drive safely' message on several VMS gantries that were located at six sections of typical expressway conditions in Qatar. We investigated how the expressway drivers perceive the VMS when implemented in different driving conditions (e.g. higher truck or car density) and surrounding environments (landmarks, buildings, bridges, exits, etc.). Besides, it was studied whether the driver's attention to the speedometer and the side mirrors was influenced. The eye-tracking data of seventy-nine drivers from the State of Qatar was analyzed, while driving in a driving simulator. It was found that a higher truck density on the expressway before the VMS location would lead to a delayed time-to-first-fixation and a lower fixation count to the VMS. The results of an ANOVA revealed that the expressway environment did not influence the drivers' average fixation duration to the speedometer and side mirrors when encountering the VMS. Therefore, no interfering effects must be expected for 'drive safely' messages at VMS locations with varying expressway traffic and surrounding conditions.