Before, During, and After COVID-19: Temporal Variations in Truck Crash Injury Severity in Oregon

Abstract: This study investigates changes in truck crash injury severity in Oregon from 2019 to 2021 across three periods: before, during, and after the COVID-19 pandemic, using econometric methods. While previous research has examined truck crashes, the specific temporal fluctuations caused by the pandemic remain underexplored. To address this, random parameters binary logit models were developed for each period, accounting for heterogeneity in the means of random parameters. These models analyze driver, weather, roadway, and crash-specific characteristics. A transferability test revealed that model parameters varied significantly across the three periods, highlighting the pandemic's dynamic impact. Key findings show that factors such as seatbelt usage, non-residency in Oregon, and driver age between 45 and 55 years unpredictably influence injury severity as random parameters. Additionally, variables such as being over 55 years old, the presence of a median, rainy conditions, and improper driving increased the probability of severe injuries. In contrast, factors like dark lighting, moderate speeds, and vertical curves were associated with a reduced likelihood of severe injuries. These results emphasize the importance of continuously updating safety countermeasures, as factors affecting crash injury severity change over time due to the pandemic's temporal instability. By adapting these measures, transportation safety professionals can reduce crashes and fatalities, ensuring a safer environment for all road users.