Human Factors in Road Design: A Review of Italian Design Standards

Human Factors are stable psychological, psychophysical, and physiological limits that influence the performance and safety of technical systems managed by humans. Roads are made for human use, but nowadays not completely on a human scale. Many studies demonstrate that Human Factors are a key factor in accident occurrence and thus it is mandatory to consider them in the definition of design standards. This research provides a methodological approach to reviewing design standards based on Human Factors. The methodology identifies which Human Factors aspects are relevant for each specific design feature. The reviewer is then able to judge if those aspects are considered using checklists. Moreover, the paper presents a review of the Italian design standards using the proposed methodology. This identifies to what extent Human Factors are considered in the Italian design standards, analyzing if they match the requirements of the three rules of Human Factors proposed by PIARC (Permanent International Association of Road Congresses). The results identify where Italian design standards consider Human Factors and where they do not. This is where further improvements should be made so that engineering solutions could match psychological requirements, for safer and ergonomic road infrastructures. The proposed approach provides a structured and systematic procedure for the analysis which has been found to be suitable also for road safety audits procedures.