Investigating Factors Affecting Injury Severity in Bicycle-Vehicle Crashes: A Day-of-Week Analysis with Partial Proportional Odds Logit Models

This study aims to investigate the factors that affect injury severity in crashes involving cyclists on weekdays and weekends separately using police-reported data ranging from 2007 to 2018 in North Carolina. Ordered logit model and partial proportional odds (PPO) logit models are developed respectively for the injury severities of crashes on weekdays and weekends. Different sets of significant factors are identified for weekdays and weekends. For the common factors identified for both weekdays and weekends, the influencing extent of significant variables varies significantly between weekdays and weekends. Older-aged cyclists, riding direction, pickup, older-aged drivers, male drivers and periods of 0-5:59 and 10:14:59 are only found significant on weekdays while speed limits of 45-55mph, piedmont areas, commercial development, head-on, and non-roadway locations are only found significant for injury severities of crashes on weekends. Speed limits, time of day, alcohol usage are found to have different or even opposite impacts on the injury severities of crashes on weekdays and weekendsThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author