Single vehicle crashes comprise about 30% to 40% of fatal crashes in most jurisdictions. While the role of alcohol and other drugs in these crashes is thought to be high, the detail of investigation of these crashes is often minimal in the (approximately) two-thirds of crashes in which the driver is killed. Overall 40% of the known BACs of drivers were greater than 0.05%, compared with 0.5% of control drivers. Cannabis (measured as carboxy-THC) was present in 19% of crashed drivers, while 0.6% of control drivers stated they had used cannabis in the previous 12 hours. Cannabis was generally found in conjunction with alcohol in crashed drivers: 16% of drivers had BAC greater than 0.05% and cannabis. No control drivers had alcohol and cannabis. The odds ratios for taking prescription and non-prescription drugs in the previous 12 hours were not significantly greater than one. (A)
Abstract