Determining the Causes of Road Pavement Distress Resulting from Human Errors in Arid and Semi-Arid Regions of Iran: A Delphi-SIWEC Study Approach

Asphalt pavements are exposed to environmental and traffic stresses, but premature failure is often accelerated by preventable human errors across the project lifecycle. This study identifies and ranks human-error-related causes of asphalt pavement distress in arid and semi-arid regions of Iran. A Delphi-validated questionnaire of 35 indicators in six dimensions (design, execution, maintenance, management, general, and inspection errors) was completed by 38 experienced pavement practitioners working in selected Iranian provinces. One-sample t-tests showed that all dimensions were rated significantly above the scale midpoint (overall mean = 3.619; p < 0.001), indicating that the experts judged human error to be an important contributor to pavement deterioration. SIWEC was then used to estimate their relative weights. Maintenance errors received the highest weight (0.187), followed by general errors (0.180) and management errors (0.179). Design errors received the lowest weight (0.145). The highest-weighted indicators were lack of trained personnel, absence of maintenance decision-support systems, delayed repair of minor defects, misinterpretation of technical regulations, and incorrect diagnosis of distress type. In this expert sample, avoidable failures were associated mainly with organisational, managerial, and post-construction practices rather than with design. The results point to workforce competence, proactive maintenance systems, and managerial accountability as the most promising points of intervention.