The effect of commercial motor vehicle (CMV) drivers' medical conditions on crash severity, are described. The severity of a crash is measured by the total number of victims, injured and dead. Count data regression models which incorporate, simultaneously, information on drivers' characteristics, crash circumstances and health status, are estimated. The fact that these variables have to be controlled adequately in order to isolate the effects of health status on crash severity, is emphasized. Results show that truck drivers with binocular vision problems and bus drivers with hypertension are involved in more severe crashes than healthy drivers. No other medical conditions considered in considered in this study has a significant effect on crash severity, but variables describing crash circumstances are significant.
Abstract