TY - JOUR
T1 - Effects of precipitation type on crash relative risk estimates in Kansas
AU - Tobin, Dana M.
AU - Kumjian, Matthew R.
AU - Black, Alan W.
N1 - Funding Information:
Kansas crash data were obtained through the National Highway Traffic Safety Administration's State Data System with permission from KS DOT. ASOS/AWOS data were obtained from the Iowa Environmental Mesonet (mesonet.agron.iastate.edu). We thank the two anonymous reviewers whose comments and insights were invaluable to improving the manuscript.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/3
Y1 - 2021/3
N2 - Crash relative risk estimates (CRREs) during rain, snow, sleet (i.e., ice pellets), and freezing rain are estimated using a matched-pair analysis in Kansas for the years 1995−2014. Variable-length event periods are defined using both crash reports and nearby Automated Surface Observing System (ASOS) and Automated Weather Observing System (AWOS) observations. Newly developed methods to extract precipitation-type beginning and ending times within ASOS/AWOS observations provide the most accurate account of precipitation type to compute CRREs. Crash relative risk is enhanced during any precipitation type, while a hierarchy of risk based on precipitation type is also evident. For property damage only crashes, CRREs during freezing rain are significantly higher than snow, which in turn are significantly higher than rain. CRREs during sleet, though statistically significantly higher than rain, are not statistically significantly different from snow or freezing rain. For casualty (injury and/or fatality) crashes, CRREs during snow and freezing rain are significantly higher than rain, but the increase in risk during sleet is not statistically significantly higher than rain. These results are consistent with expectations, but are quantified here for the first time. These hierarchies are insensitive to the use of all crashes versus only those with crash-reported precipitation or precipitation-induced roadway surface conditions to compute CRREs. The risk of a single-vehicle crash is higher than a multiple-vehicle crash during snow, sleet, and freezing rain, whereas the opposite was found for rain. This hierarchy is most prominent during weekdays before noon.
AB - Crash relative risk estimates (CRREs) during rain, snow, sleet (i.e., ice pellets), and freezing rain are estimated using a matched-pair analysis in Kansas for the years 1995−2014. Variable-length event periods are defined using both crash reports and nearby Automated Surface Observing System (ASOS) and Automated Weather Observing System (AWOS) observations. Newly developed methods to extract precipitation-type beginning and ending times within ASOS/AWOS observations provide the most accurate account of precipitation type to compute CRREs. Crash relative risk is enhanced during any precipitation type, while a hierarchy of risk based on precipitation type is also evident. For property damage only crashes, CRREs during freezing rain are significantly higher than snow, which in turn are significantly higher than rain. CRREs during sleet, though statistically significantly higher than rain, are not statistically significantly different from snow or freezing rain. For casualty (injury and/or fatality) crashes, CRREs during snow and freezing rain are significantly higher than rain, but the increase in risk during sleet is not statistically significantly higher than rain. These results are consistent with expectations, but are quantified here for the first time. These hierarchies are insensitive to the use of all crashes versus only those with crash-reported precipitation or precipitation-induced roadway surface conditions to compute CRREs. The risk of a single-vehicle crash is higher than a multiple-vehicle crash during snow, sleet, and freezing rain, whereas the opposite was found for rain. This hierarchy is most prominent during weekdays before noon.
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U2 - 10.1016/j.aap.2020.105946
DO - 10.1016/j.aap.2020.105946
M3 - Article
C2 - 33385963
AN - SCOPUS:85098597502
SN - 0001-4575
VL - 151
JO - Accident Analysis and Prevention
JF - Accident Analysis and Prevention
M1 - 105946
ER -
