This study conducted in New Zealand in 2012 investigated the attitudes, prevalence, habits and self-reported risks associated with drug-driving, along with possible countermeasures. Telephone and internet surveys were used for a general population sample. Face-to-face interviews, mainly in prisons, surveyed habitual users of four main drug types: alcohol and other drugs, cannabis, methamphetamine and benzodiazepine.
Alcohol was the main substance used before driving, followed by alcohol and cannabis together and cannabis alone. Nearly half the general population respondents had driven after taking drugs or alcohol and a sizable proportion after taking drugs other than alcohol.
Many respondents in the face-to-face group said they took risks when driving. Only a third had a full licence despite driving for more than 10 years. The majority had been involved in a crash, more than half being at fault.
Countermeasures preferred by both the general population and the habitual drug users included randomised roadside testing, vehicle impoundment and enforcement. Social media was considered effective by the general population but not by the face-to-face group. Recommendations include research into the effects of drugs on driving and the development of programmes to reduce risky driving by drug users.