A Random Parameters Multinomial Logit Model Analysis of Median Barrier Crash Injury Severity on Wyoming Interstates

This paper investigated factors influencing injury severity of crashes involving median traffic barriers, including the impact barrier characteristics and their geometric features in Wyoming. Combining field data inventoried barriers with crash on Wyoming interstates highways, a random parameters multinomial logit (mixed logit) model was estimated. methodological approach allowed for possibility estimated to vary randomly across observations account heterogeneity respect driver characteristics, roadway attributes, vehicle characteristics. The estimation results indicated concrete installed front side-slopes box beam were associated severe crashes. It also found that sports utility vehicles, pickups, improperly restraint occupants are complex significantly observations. Other statistically significant variables increase likelihood rural interstate roads, side-slope, lateral offset less than 2 feet, rollover These fixed findings this research point need further investigate impacts sport severity.