Investigating the trend of road traffic fatalities in Malawi using Mann-Kendall statistic

Fatalities due to road accidents remain a major challenge worldwide. In the recent years, Malawi, one of the developing African countries with a total population of about 19 million has also been witnessing a very high fatality rate [of about 31 crash deaths per 100,000 population in 2016] compared to most of its neighbours in the region. This seems to be continuously increasing even with several intervention measures, such as, speed and alcohol impairment laws, and laws for mandatory seatbelt and helmet use. In view of this, the study attempted to investigate the trend of road fatalities in Malawi, such that effectiveness of the existing measures can be established. For this, archived crash data of road fatalities between years 2000-2021 were used to undertake intervention and trend analyses. The method of Cumulative Summation was used to identify intervention points in the series, followed by the Mann-Kendall statistic (τ) to determine the trend during the intervened period using the non-parametric Rank-Sum test to support the findings. The results showed that the trend has been decreasing in the early years of legislating policy measures [2000-2012] and, thereafter [2013-2021], increased significantly [τ = 0.8333]. This suggests that there was acceptance of the measures by the motorists/public in the early years of implementation [2000-2012], which might have been overshadowed by vehicle population growth and weak enforcement mechanism that have seen the trend increasing lately. The study therefore suggests that there is still a scope to review the intervention measures in their effective implementation as well as regular monitoring.