The role of drivers’ schemes on traffic signs comprehension

Abstract

Current road signs confront a fundamental issue: are signs displayed in different devices (posted, on-board, painted or electronic) making the most of the same design rationale? Convergent design principles help drivers enjoy an easier coding, learning and retrieval of the schemes enhancing comprehension. This paper focuses on posted road signs (painted vs electronic) that locate events and how well they complement each other. Fixed signage must be the starting point (the scheme formed) to investigate how electronic devices (the new information) can functionally locate variable events or situations. The paper presents preliminary data regarding a sample of 39 participants. The experimental task consisted of 27 blocks of traffic signs. Electronic-adapted traffic signs were shown to all participants; however, only one group was exposed also to fixed (painted) signs. A 3x2 mixed design was used (experimental condition as inter-group factor and event location as intra-group factor), and in addition, the design also included a working memory measure as a covariate. Comprehension rates were high in all formulas of event location. As previous studies, time response showed higher means when the variable event is located ‘between’ two referents. Moreover, ‘working memory (WM) span’ showed a marginal significance with time response. This result leads to an interesting question about the consideration of influence of individual differences in WM capacity when designing complex traffic messages. Overall, results highlight the importance of understanding how complex traffic messages are encoded, processed and de-encoded, and the limits human WM may pose.