A scoping review of the impact of temperature and humid environmental conditions on drivers’ safety across geographical locations

Abstract Aim Road traffic incidents are one of the most significant causes of death globally, with previous research showing that many meteorological factors influence road traffic safety. The purpose of this scoping review was to examine the effect of high ambient temperature and humidity on road traffic incidents across various climatic zones. Subject and methods A search of Ovid MEDLINE, CINAHL, PsycInfo (ProQuest), SafetyLit, and Scopus databases was undertaken to identify studies published between 2002 and 2022, focusing on the association between driver safety, and temperature and humid climate. Available data were extracted and analyzed to evaluate the impact of temperature and humidity on road traffic incidents. Results Forty-eight studies reported on the influence of temperature on driver safety. Two of four studies conducted in polar and subpolar climates reported negative correlations; nine of 11 studies in tropical and subtropical climates reported positive correlations; and 15 studies in temperate climates reported positive whilst five studies reported negative correlations between temperature and traffic incidents. In addition, only ten reported the influence of humidity, and two reported positive correlations, three reported negative correlations, and four reported no significant association. No characteristic tendency was found in the association between humidity and traffic incidents. Conclusion There is an association between climate and road traffic incidents, with increases found in both extreme hot and extreme cold environmental conditions; however, the influence of relative humidity is less evident.