Impact of Different Levels of Rainfall on the Road Crash Count and Severity in Dhaka City

No less than 386 crashes, 403 fatalities, and 686 injuries occurred on Dhaka’s roads in those days when at least 1 mm drops of rain were recorded in the city from 2018 to 2022, which are around 31%, 31% and 37% of the total reported crashes, fatalities, and injuries respectively. This study has tried to explore the impact of rain on road traffic crashes in Dhaka city. Due to different roadway and roadside environments and changing traffic patterns and behavior resulting from diverse weather characteristics, there would be differences in crash characteristics and risk factors of crashes in different levels of rain weather than in normal weather. Considering this hypothesis, this study has made a comparative analysis of crashes that occurred in different levels rainy and dry weather integrating multiple risk sources using the logistic regression technique. This analysis also sheds light upon the key risk factors and their interaction effects on each other. At the very outset, the study has made a matched pair and independent comparative analysis under the different intensities of rainfall to pair wet weather with dry weather to determine the relative risk of a crash, fatality, and injury. This analysis considers 110 independent variables under different categories including crash type, vehicular involvement, pedestrian hit by different vehicles, temporal factors, etc. The models identify some important factors that have significant impacts on safety risk at different levels of rainfall in Dhaka city. Based on some directions and special requirements that need to be integrated into road safety policies to reduce road crashes in rainy, wet, and adverse weather are highlighted.