A comprehensive review of the socio-economic appraisal methodologies of the road safety measures

Road safety measures, e.g., speed limits, are widely used globally to prevent and reduce the number of road crashes, injuries, and fatalities. However, implementing such preventive measures has long-term and complex social, environmental, and economic interdependencies and impacts. Therefore, socio-economic appraisals of road safety measures are crucial for identifying such complex interdependencies and impacts on the well-being of individuals, society, the economy, and the environment. The study carries out a comprehensive review of the scientific literature dealing with socio-economic appraisal methodologies of road safety measures. The study comprehensively reviewed the scientific literature on socio-economic appraisal methodologies for road safety interventions. The review follows PRISMA guidelines for selecting scientific articles across Google Scholar, Scopus, and Web of Science. From 535 records identified on 18 January 2025, 80 studies (including grey and peer-reviewed articles in English) were selected. These studies are reviewed based on six themes, namely: (a) methodological frameworks of the methodologies, (b) classification, (c) key indicators, (d) datasets, (e) strengths, limitations, and biases, (f) stakeholders’ involvement and impacts on policymaking. The review indicates that the existing socio-economic appraisal methodologies for road safety measures effectively capture specific dimensions, e.g., crash rate reduction, willingness-to-pay for road safety and improved social well-being. However, these methodologies also exhibit inconsistencies while accounting for factors like price inflation and replicability. The review identifies six methodological limitations that accentuate significant future research and innovation opportunities. The review also presents recommendations for future research to address the identified limitations.