Mark R. Anderson
Date of this Version
Petr, Jacob J. (2019). An observational study of winter weather-related traffic crashes in Nebraska. MS Thesis. University of Nebraska, 2019.
The responsibilities of meteorologists have evolved over time from simply providing a forecast to needing to also understand how those predictions will impact society and then communicating those risks in a clear, concise, and consistent manner. Increased motor vehicle crash numbers due to adverse weather conditions represent one such impact worthy of further study. Snowfall, in particular, significantly increases the overall risk of a crash, which can result in extensive property damage, severe injuries, and even loss of life.This project seeks to supplement traffic crash information in Nebraska by assessing how snowfall impacts crashes across the state. Crash data were obtained from the Nebraska Department of Transportation (NDOT) for the years 2007 through 2017. Total number of crashes, injuries, and fatalities are first evaluated temporally by year, month, day of week, and time of day. Crashes with snow reported by the investigating official as the primary or secondary weather condition were then identified. Variations between snow-related crashes and all crashes were calculated to identify how snowfall affects temporal crash distributions. It was found that snow-related crashes increase crash totals on weekends as well as during the morning hours relative to all crashes. The spatial distribution of snow-related crashes was also assessed at the individual crash, county, and NDOT district locations. The versatility of the newly developed Nebraska Winter Severity Index (NEWINS) is also evaluated to determine its utility for determining how different winter storm severities impact snow-related crash totals. Furthermore, the individual meteorological variables that go into creating the NEWINS are also assessed. In general, it was found using the NEWINS that longer duration, larger winter storms caused the highest number of crashes. In addition, winter events with higher snowfall totals and lower visibilities also resulted in higher crash totals. Lastly, high impact crash days were identified from daily crash totals and the occurrence of multi-vehicle chain‑reaction crashes, the largest of which resulted in a 31-car pileup. This project seeks to provide insight into when and where Nebraskans are typically at greater risk of a crash due to winter weather conditions.
Advisor: Mark R. Anderson