Study Projects Road Traffic Injuries in Ethiopia Will Increase Through 2035

A time-series forecasting analysis examining road traffic injuries in Ethiopia indicates that annual road-related deaths and disability-adjusted life years are set to escalate substantially through 2035 under current trajectories. Utilizing historical health metrics spanning from 1990 to 2023 derived from the Global Burden of Disease 2023 study, investigators established that national fatalities attributable to vehicular crashes increased from an estimated 15,239.82 deaths in 1990 to 35,049.51 deaths in 2023. This trajectory represents a 130.0 percent rise in absolute annual mortality across the 34-year observational window. The analysis simultaneously evaluated disability-adjusted life years, a comprehensive metric combining years of life lost due to premature mortality with years lived with disability, showing a 96.1 percent rise from 1,007,234 in 1990 to 1,974,902 in 2023. These historical expansions in casualty figures frame a widening public health challenge for the nation, highlighting severe emerging strains on clinical infrastructure, acute emergency networks, and national health planning frameworks.

The study was designed to bridge critical gaps in national injury epidemiology by combining retrospective surveillance with future mathematical forecasting. Although prior assessments evaluated injury burdens in Ethiopia broadly through systematic reviews or localized clinical registries, earlier work primarily analyzed broad trauma categories or relied on specific institutional patient cohorts that did not encompass national population trends. Furthermore, previous investigations rarely tracked deaths, overall disability burdens, and age-standardized rates concurrently within an integrated framework. To establish a rigorous assessment, the research team analyzed annual metrics covering both sexes combined, extracting counts and rates alongside their respective 95 percent uncertainty intervals directly from the Global Health Data Exchange repository. The primary investigative scope focused on assessing 34 years of documented health records to establish temporal trajectories, projecting future disease burdens across the 2024 to 2035 period using statistical time-series models, and evaluating national performance against global safety benchmarks established under the United Nations Sustainable Development Goals.

An essential epidemiological finding of the historical analysis lies in the pronounced divergence between absolute casualty numbers and demographic-adjusted population rates. While raw death tolls more than doubled over the three decades, the age-standardized mortality rate remained relatively stable, shifting marginally from 30.78 deaths per 100,000 population in 1990 to 30.90 per 100,000 population in 2023, reflecting a slight 0.39 percent endpoint change. When analyzed across all intervening annual observations via linear regression models, the Estimated Annual Percentage Change revealed a statistically significant downward trajectory of 0.53 percent per year. An even more substantial reduction emerged for the age-standardized disability rate, which dropped 14.4 percent between endpoints from 2,034.45 DALYs per 100,000 population in 1990 down to 1,741.26 per 100,000 population in 2023. The regression model showed that this rate contracted at an average rate of 1.06 percent per year across the historical observation period.

This statistical contrast highlights how underlying demographic transitions can reshape national health outcomes even when baseline age-specific exposure risks improve. Because age-standardized measures rely on a fixed standard population to remove the effects of aging and demographic shifts, they capture changes in per-capita systemic vulnerability and health service performance. The downward trend in standardized rates likely reflects past developments in road infrastructure, incremental expansions of surgical capacity, improvements in emergency trauma response, and public safety initiatives implemented over past decades. However, Ethiopia experienced concurrent surges in population growth, rapid urbanization, and accelerated motorization during this same historical period. These broader demographic expansions dramatically increased the total number of individuals encountering transit environments daily. Consequently, the expanded population exposure outpaced the modest decreases achieved in individual age-adjusted risk, producing a continuous rise in total casualties and injury-related disabilities across society.

To evaluate the trajectory of road safety over the coming decade, researchers employed non-seasonal autoregressive integrated moving average modeling to project outcomes through 2035. Candidate model structures were evaluated on raw scales using second-order differencing, which proved optimal according to the corrected Akaike information criterion, Akaike information criterion, and Bayesian information criterion. The final configurations identified an ARIMA(0,2,0) structure for both absolute deaths and absolute DALY counts, an ARIMA(0,2,1) model for age-standardized mortality rates, and an ARIMA(1,2,1) specification for age-standardized disability rates. Stationarity was assessed through augmented Dickey–Fuller and Kwiatkowski–Phillips–Schmidt–Shin tests, while residual diagnostics were evaluated using the Ljung–Box test at seven lags and normality was checked using Shapiro–Wilk assessments. All selected models demonstrated goodness of fit without statistically significant residual autocorrelation, satisfying the diagnostic criteria required to run multi-year forward projections.

The predictive models underwent five-year out-of-sample validation to establish forecasting behavior, training candidate structures on data recorded between 1990 and 2018 to forecast outcomes realized between 2019 and 2023. During this validation phase, predictive precision was tracked using mean absolute error and root mean squared error metrics. For the absolute mortality model, out-of-sample validation yielded a mean absolute error of 779.64 and a root mean squared error of 926.57. For disability-adjusted life years, these corresponding error metrics measured 63,532.82 and 73,767.48. When tracking standardized indicators, the age-adjusted mortality rate model registered an MAE of 0.662 and an RMSE of 0.815, while the age-standardized DALY rate showed an MAE of 62.15 alongside an RMSE of 69.77. Researchers emphasized that while these evaluation metrics document predictive stability across the five-year holdout window, short-range validation remains limited in establishing definitive accuracy for projections extending across an eleven-year forward horizon.

Applying these validated equations to the complete dataset yielded substantial projected increases across all four analyzed burden metrics through 2035. Annual road traffic injury fatalities are forecast to climb from 35,049.5 in 2023 to 53,210.9 by 2030, eventually reaching 66,183.4 annual deaths by 2035, with a 95 percent prediction interval spanning from 41,319.7 to 91,047.0 deaths. Disability burdens are predicted to experience a parallel expansion, rising from approximately 1.97 million DALYs in 2023 to 2,935,043 by 2030 and reaching 3,620,858 DALYs by 2035, with prediction bounds between 2,081,637 and 5,160,079. Unlike the historical period where standardized rates fell, future projections indicate rising rates: age-standardized mortality is projected to increase from 30.9 per 100,000 population in 2023 to 42.2 in 2030 and 50.3 in 2035, while age-standardized DALY rates are forecast to climb from 1,741.3 per 100,000 in 2023 to 2,292.0 in 2030 and 2,687.2 in 2035.

These forecasts carry severe implications for Ethiopia’s commitment toward Sustainable Development Goal Target 3.6, which established an international target to reduce road traffic crash deaths and serious injuries by 50 percent by 2030 relative to a 2015 baseline. Historical records show that road traffic deaths in Ethiopia totaled 21,764.3 in 2015, meaning Target 3.6 required reducing annual deaths to below 11,000. Instead, documented fatalities expanded to 35,049.5 by 2023 and are mathematically projected to surpass 53,000 by 2030. Standardized mortality similarly rose from 22.8 per 100,000 population in 2015 to 30.9 in 2023, heading toward an estimated 42.2 by 2030. To model an alternative trajectory, the investigators examined an illustrative policy scenario featuring a 3.0 percent compound annual reduction in age-standardized mortality starting from 2023, reflecting coordinated implementations of speed management, seat-belt enforcement, helmet compliance, and drink-driving prevention. Under this hypothetical 3 percent reduction path, the age-standardized mortality rate would decrease to approximately 24.9 per 100,000 by 2030 and 21.2 by 2035, demonstrating that structured preventive interventions could substantially diverge from current trends.

The projected expansion in trauma volume underscores pressing demands across Ethiopia’s clinical, surgical, and prehospital emergency care systems. The authors noted that escalating severe injuries inevitably generate heightened requirements for ground ambulance fleets, trained prehospital personnel, emergency department resuscitation beds, surgical staffing, critical care capacity, blood products for transfusion, and long-term physical rehabilitation networks. However, the study emphasized that epidemiological forecasts cannot directly determine exact facility-level supply needs on their own. Calculating concrete equipment, staffing, and bed quotas requires granular local clinical data, including facility workload metrics, emergency room occupancy rates, vehicle response-time registries, and comprehensive health workforce audits. Translating aggregate national forecasts into operational readiness requires establishing integrated road-injury surveillance systems capable of continuously reporting crash typologies, road-user classifications, regional transit patterns, prehospital transit intervals, and definitive clinical outcomes.

The investigators outlined several structural limitations that temper the interpretation of these findings and highlight areas for future methodological improvement. Because the research relied on statistical extrapolation of historical time-series patterns, the primary ARIMA models cannot account for unobserved future policy changes, sudden economic shifts, or emerging legislative reforms. Furthermore, limitations in Ethiopia’s vital statistics registry and historical cause-of-death reporting introduce potential measurement errors into baseline Global Burden of Disease estimates, meaning reported uncertainty intervals may not capture all systemic data gaps. The absence of disaggregated data on road-user categories, vehicle types, specific risk factors, geographic variations, and prehospital emergency interventions further constrains contextual evaluation. Finally, the ecological nature of the national time-series design precludes inferring direct causal links between specific underlying risks and macroscopic injury trends, highlighting the necessity of verifying modelled projections against strengthened prospective surveillance infrastructure.

Subject of Research: Time-series forecasting of road traffic injury burden and healthcare system implications in Ethiopia

Article Title: Forecasting the burden of road traffic injuries in Ethiopia through 2035 and implications for emergency care systems and sustainable development goal target 3.6

Article References: Kassa, B. D., Tsegaye, Y. A., Belay, B. M., & Malaju, M. T. (2026). Forecasting the burden of road traffic injuries in Ethiopia through 2035 and implications for emergency care systems and sustainable development goal target 3.6. Discover Public Health. https://doi.org/10.1186/s12982-026-03313-y

Image Credits: AI Generated

DOI: 10.1186/s12982-026-03313-y

Keywords: Road Traffic Injuries, Ethiopia, Global Burden of Disease, ARIMA Modeling, Public Health, Trauma Systems, Emergency Care, Mortality Projections, Sustainable Development Goals, Injury Epidemiology, Forecasting, burden