Ergonomic Criterion in the Design of Roadside Information: Letters Size Methodology Verification

Purpose: The aim of the analyses was to present the applicability of the developed methodology. Method: Methodology was developed based on interdisciplinary analyses of research into human perceptual capabilities and recommendations for optimal human visual fields. The research was conducted on the example of informational road boards. A range of font dimensions on informative road boards was analysed. These dimensions are subject to international standardisation and legal regulations. The use of font size groups depends on the type of road and the permitted driving speed. Findings: The analysed methodology made it possible, for example, the determination of reference distances from which the fonts on boards will be visible, the recommended font sizes for the expected distance from which the sign should be visible, the assessment of the distance and height of the positioning of information or advertising boards in relation to the road and the driver's field of vision, the recommended limiting number of letters/phrases on information boards (for slow or fast readers) depending on the driving speed, the time during which the observed words on the sign will be observed in the recommended field of vision. Practical implication: The applied methodology may have a very wide practical application in the design of information systems in which text messages are used. During the analysis, the authors used a developed computer tool that facilitates both the process of evaluating existing information boards and designing new ones. Originality/value: The authors verified a simulation model to support the selection of letters sizes on information and advertising boards.