The contribution of excessive or inappropriate speeds to road traffic crashes and fatalities: A review of literature

Road traffic crashes and fatalities pose a significant global challenge, particularly in low- and middle-income countries (LMICs), where a major cause is consistently linked to speeding (i.e., excessive or inappropriate speeds). However, the existing body of evidence regarding the estimated contribution of speeding to crashes and fatalities, remains limited and is considered outdated. This paper bridges this knowledge gap by reviewing evidence on the contribution of speeding to crashes and fatalities. The review draws on a wide range of sources including peer-reviewed studies on the subject, road safety monitoring-reports and available data summaries (104 sources). Data reliability was confirmed by including studies based on or linked to primary sources like police records, and excluding those with poor quality, implausible results, or lacked references to primary sources. The included sources contained 37 estimates from high-income countries (HICs), and 67 estimates from LMICs. Globally, HIC and LMIC estimates of contribution were calculated by assigning weights based on the proportion of fatalities in each country under this study. The results indicated that speeding contributes to approximately 54 % of fatalities worldwide, 57 % in LMICs, and 28 % in HICs. This translates to a speeding-related death every 49 s, with a 95 % likelihood of occurring in LMICs. These findings carry significant implications for policymakers emphasizing the urgent need to prioritize interventions that reduce speeding and improve road safety. Investigating gaps in LMICs data sources is a critical priority. In-depth studies and speeding intervention evaluations will enhance our current understanding of speeding contribution to crashes and fatalities.