COMPARATIVE ANALYSIS OF QUARTERLY ROAD ACCIDENT INCIDENCE ACROSS NIGERIA GEOPOLITICAL ZONES (2020-2022)

This study presents a comparative analysis of quarterly road accident incidences across Nigeria’s six geopolitical zones North Central, North East, North West, South East, South South, and South West from 2020 to 2022. Road traffic accidents remain a major public health and socio-economic concern in Nigeria, with thousands of lives and significant economic resources lost annually. Understanding regional and temporal variations in accident patterns is essential for effective road safety planning, resource allocation, and targeted interventions. This study therefore examines whether accident causes differ significantly across the geopolitical zones over the three-year period. Quarterly accident counts for selected causes Speed Violation (SPV), Tyre Burst (TBT), Mechanical Defect Violation (MDV), Wrong Overtaking (WOT), and Dangerous Driving (DGD) were compiled and analyzed using appropriate non-parametric statistical techniques. The Friedman test was used to evaluate overall differences in accident incidences across zones, while the Wilcoxon signed-rank test with Bonferroni correction was applied for pairwise comparisons where necessary. Descriptive summaries and graphical displays were also used to highlight temporal trends and distribution patterns. The results show no statistically significant differences across zones for SPV, TBT, MDV, or DGD, indicating a relatively uniform distribution of these accident causes nationwide during the study period. However, WOT exhibited a significant overall difference across zones, suggesting regional variation in overtaking-related accidents. Despite this, pairwise post-hoc tests did not identify specific zone pairs with statistically significant differences under the conservative Bonferroni-adjusted alpha level. This implies that while regional disparities exist for WOT, limited sample size and strict adjustments may have reduced power in detecting specific contrasts. The study concludes that most accident causes examined show similar patterns across Nigeria’s geopolitical zones, except for WOT, which requires further targeted investigation. Recommendations include strengthening nationally consistent enforcement strategies, improving data quality across zones, enhancing driver education, and implementing infrastructure improvements in high-risk areas. The study contributes to the literature by providing a spatial-temporal analysis of accident causes using quarterly data and highlights areas for further research, particularly on wrong overtaking and the inclusion of additional explanatory variables.