Economic evaluation finds higher social returns from eliminating severe conflicts in road safety projects, suggesting priority for physical intervention over awareness campaigns.
Key Points
Develop and apply an evaluation framework using the Social Return on Investment (SROI) method to quantify the broader socioeconomic impacts of low-cost road safety engineering interventions.
Evaluated 15 road safety improvement projects across four hierarchical tiers: removing severe conflicts (Tier 1), reducing speed (Tier 2), managing conflicts (Tier 3), and increasing awareness (Tier 4).
Monetized social and economic outcomes across three stakeholder groups (road users, communities, and government agencies) over a 5-year evaluation period.
Applied statistical ANOVA and sensitivity analyses to compare performance across intervention tiers and test model robustness.
Higher-tier interventions generated significantly greater social returns (F(3,11) = 16.51, p < 0.001), with average SROI ratios of 17.0 (Tier 1), 15.6 (Tier 2), 11.5 (Tier 3), and 8.1 (Tier 4).
Crash reduction and improved community satisfaction represented the primary drivers of positive social value across all evaluated projects.
Increases in travel time, vehicle fuel consumption, and greenhouse gas emissions formed the primary offsetting costs that diminished net SROI.