In a recent study conducted in our Lab we found that under certain conditions of perceptual load on the road and on the roadsides the presence of small advertising billboards increased the response time to critical events that were initiated from the sides of the road and also increased the number of crashes. On the other hand, the effect of very large advertising billboards was minimal. One possible explanation for this finding is that the influence of a billboard depends on the efforts required to perceive its content. Apparently, our participants had to invest more effort in perceiving the small billboards, and therefore were less attentive to critical events that occurred near to these types of billboards.
The current ongoing study tests how presentation of the billboard content influence the driver's distraction level, driving performance and safety. In the first phase of the study, many advertising billboards were photographed to form a large database of billboards and two kinds of categorization processes were conducted. The first was an objective categorization process which measured different aspects of the billboards (e.g., number of colors, text percentage, graphics percentage, logos, etc.). The other was a subjective categorization process which included subjective assessments made by students from the University of Haifa who participated in this study. In the next phase of the study, an experiment was conducted. Three concurrent tasks were performed: a tracking task, a visual identification task - identification of a color change in a fixed circle (to simulate a traffic light), and observing an advertising billboard, which was presented briefly. After the billboard disappeared, a question related to it was presented. Cluster analysis revealed that the types of billboards can be divided into three categories as a function of their effect on particioants' performance on the tracking or color identification tasks. These categories are: billboards that affected the tracking task only; those that affected the color identification task only; and those that did not affect either of these tasks.
The last phase of the study tests these three billboards categories within a driving simulator under the different perceptual load conditions on the road and on the roadsides, combined with events occurring at different locations. We hope that the findings of this study will help to distinguish the most problematic road conditions and billboard categories from those that are less harmful to drivers.