Author(s): Maryam Haya, Sulaf Al-Karawi, Francine Rubin, Yoassry Elzohairy
Estimating the incidence of fatigue-related fatal and injury collisions using police-reported collision data has been a considerable challenge to traffic safety researchers. The role of fatigue in collisions is difficult to measure due to the absence of an objective test for the level of fatigue or sleepiness of drivers involved. Ontario introduced an operational definition for fatigue-related collisions and a statistical model developed and approved in 2006 by the Canadian Council of Motor Transport Administrators’ (CCMTA) Road Safety Research and Policies (RSRP) Committee, and the National Collision Database (NCDB). In 2014, Ontario refined the operational definition to obtain a more comprehensive measure of fatigue-related collisions. The operational definition employs a stepwise selection algorithm based on certain crash criteria to estimate the extent of fatigue involvement in fatal and injury collisions. The operational definition accurately identified two-thirds of fatigue-related collisions as determined by police or coroner reports. Results showed that fatigue may be a contributing factor in approximately 20% of fatal collisions and 27% of injury collisions from 2002 to 2011. On average, fatigue contributed to 144, or 20 percent of fatalities per year. Large trucks were 25 times more likely to be involved in a fatigue-related collision compared to their involvement in all collisions. Male drivers were twice as likely to be involved in a fatigue-related collision as female drivers. Overall, the collision involvement rate was 14.9 per 10,000 licensed drivers.