Spatiotemporal dynamics and fatality risk patterns of road traffic crashes in Nigeria (2020–2024)

Abstract Background Road traffic crashes pose a significant public health issue in Nigeria, but there is limited national-level analysis of their spatial and temporal patterns. This study investigates the distribution, temporal trends, and severity of reported road traffic crashes across Nigeria’s 36 states and the Federal Capital Territory (FCT). Methods We conducted a retrospective longitudinal study analysing quarterly Federal Road Safety Corps (FRSC) crash data across 37 jurisdictions from Q4 2020 to Q1 2024, covering 14 quarters with 518 state-quarter observations. Key indicators included the fatality rate (deaths per crash), casualty rate, and severity index. State-level comparisons summarised crash burden and lethality, and, when population data were available, measured crashes and fatalities per 100,000 residents. Exploratory trend projections were produced using an ensemble of a linear (OLS) trend, exponential smoothing (ETS, α = 0.7), and ARIMA (0,1,0) with drift. Results Showed that crashes peaked at 13,656 in 2022, with 6456 deaths, and then declined by 22.3% in 2023. The fatality rate per crash stayed steady between 0.47 and 0.48 deaths from 2021 to 2023, despite decreasing crash numbers. Geographically, crash burden was concentrated: the FCT had the highest crash count (4852) but a low fatality rate (0.224), while northern states such as Sokoto, Katsina, and Kaduna had higher death rates per crash with fewer crashes. After adjusting for population, the ranking of states changed, showing that some of the burden is due to population size. Speed violations and vehicle-related issues were common factors noted by officers. Projections suggest that quarterly crash numbers will likely remain high in the short term, though uncertainty is increasing over time. Conclusion The results emphasise the importance of shifting to risk-based road safety strategies in Nigeria, with a primary focus on speed regulation, vehicle safety checks, and enhanced emergency response systems. These recommendations are inferred policy implications of the observed patterns rather than evidence of intervention effectiveness.