Large-scale Effect of Inclement Weather Conditions on Crash Risk over Texas

Texas is the second largest state in U.S with a relatively high and diverse population. Thousands of crashes occur each year over Texas. This study aims to analyze the large scale effect of rainfall on road crashes. Precipitation events were categorized into four main types based on their intensities and durations: (1) high intensity with short duration, (2) high intensity with long duration, (3) low intensity with short duration, and (4) low intensity with long duration. The spatial and temporal variability of events and crashes are considered as important factors on crash risk ratio. For each crash that occurred during 2015 over Texas, precipitation intensity at the time of crash and duration of that event is calculated based on nearest 4x4 km NEXRAD radar grid. Overall, results indicate that each of these categories can have different effects on crashes. Based on geospatial analysis, urban counties are affected by these factors with more injury and fatalities relative to rural ones.