In order to study the role of drugs in driving, a responsibility analysis was developed to allow an assessment to be made of the driver's culpability or responsibility in an accident. Factors possibly mitigating drivers' responsibility in each accident were identified and scored. Factors considered were: condition of road, condition of vehicle, driving conditions, accident type, witness observations, road law obedience, difficulty of task, and level of fatigue. If a sufficient number of mitigating factors were identified a driver would be found to be either partly or totally exonerated from blameworthiness and scored either as a contributory or non-culpable driver. If drugs present in a driver contributed to accident causation, it would be expected that they would be over-represented in culpable drivers, i.e. those drivers not exonerated from blame. A total of 341 driver fatalities occurring in Victoria were analysed for blood alcohol content (BAC). Twenty-nine percent had a BAC over .05% (the legal limit in Victoria). Alcohol-positive drivers were statistically over-represented in the culpable group (p less than .001), in single-vehicle accidents (p less than .05) and those accidents in which vehicles left the road for no apparent reason (p less than .001). Odds-ratio estimation of relative risk of culpable and non-culpable drivers showed that the relative risk rose disproportionately to BAC. (A).
Samenvatting