Rising Trend in Traffic Accident Mortality in Iran After a Decade of Decline (2006-2022): Time to Raise the Alarm

Background This study examines epidemiology and trend of mortality rates due to traffic accidents in Iran from 2006 to 2022. Methods Data were collected from the Iranian Legal Medicine Organization and the Statistical Center of Iran. Age-standardized mortality rates were calculated using direct standardization. A Latent Class Growth Mixture Model (LCGMM) was employed to evaluate trends and identify provinces with similar patterns. Results From 2006 to 2022, Iran recorded 325,851 traffic accident deaths, with a median age of 34 years; 78.8% were male. Most deaths occurred on intercity roads (63.84%, n = 208,021), followed by urban roads (27.73%, n = 90,365) and rural roads (7.63%, n = 24,859). Mortality rates declined significantly from 38.86 per 100,000 in 2006 to 19.85 in 2017 but increased to 23.00 per 100,000 in 2022, underscoring a concerning public health issue. A reverse J-shaped trend was identified nationally using LCGMM, showing an initial decline (intercept: 48.13, SE = 1.32; slope: -3.67, SE = 0.34) followed by a significant upward trend (quadratic term: 0.14, SE = 0.02, p < 0.001). The quadratic term's highly significant p-value highlights the importance of this non-linear pattern. At the provincial level, six distinct mortality trend classes were identified, highlighting significant regional variations. Most provinces exhibited a reverse J-shaped pattern, except Sistan and Baluchestan and Kohgiluyeh and Boyer-Ahmad, which showed U-shaped trends. Conclusion After a decade of decline (2006–2017), Iran’s traffic fatalities resurged post-2017, potentially linked to economic strain, aging vehicle fleets, and inconsistent enforcement of safety regulations. Targeted interventions —subsidies for safer vehicles, infrastructure upgrades, and regional policies— are urgently needed to reverse this trend and align with global road safety goals.