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Drug Driving – What the research shows

CrimBrief The Official Blog of the AIC

14 August 2014

The NSW government statistics on drug driving deaths released this week by NSW Police Minister Stuart Ayres revealed that in the past four years, at least 166 people died on NSW roads in crashes involving motorists with illicit drugs (cannabis, speed and/or ecstasy) in their system. That represents 11 percent of all road fatalities in NSW. In fact, Mr Ayres reported that 40 percent of drug driving offences and fatal crashes involved a drug driver under the age of 30.These statistics highlight a serious safety problem on our roads.

This correlates with previous AIC research which has shown that many offenders in police custody have a dangerous attitude when it comes to taking drugs and driving.

Our 2008 report Drug driving among police detainees in Australia authored by Kerryn Adams, Lance Smith and Natalie Hind used data from the AIC’s Drug Use Monitoring Australia program. The researchers examined the prevalence of drug driving among a sample of 1,714 police detainees in 2005 and 2006. If the levels of drug use seem particularly high, remember the people surveyed were a specific sub-set of the general population—they had been detained or arrested for offences including drug offences.

The study found that two-thirds (65%) of detainees had reported driving after using drugs and/or alcohol in the previous 12 months, which is significantly higher than the incidence of drug driving in the general population.

When it comes to drug driving rates in the general population, the Australian Institute of Health and Welfare’s 2010 National Drug Strategy Household survey shows the incidence of drug driving reduced slightly from 25 percent of males surveyed in 2007 to 21 percent in 2010, and similarly for females from 14.4 to 13.2 percent. This still highlights a problematic attitude to driving under the influence of drugs.

Our 2008 report shows that in terms of the frequency of drug driving, detainees who reported driving after using heroin were most likely to report doing so at least once a week (62%). For other types of drugs, comparable figures were:

  • cannabis—58 percent
  • amphetamine/methyl amphetamine—50 percent
  • benzodiazepines—32 percent
  • alcohol—25 percent
  • cocaine—15 percent
  • alcohol + any of these drugs—29 percent.

The majority of detainees reported that drugs had a negative impact on their driving ability—of all drugs, benzodiazepine users rated that drug as most likely to have had a negative impact on their driving ability (85%). Consistent with past findings, detainees reported that drugs such as heroin, cocaine and alcohol also severely affected driving ability.

At the same time, there were detainees who appeared dangerously deluded about the effect of drugs on their driving abilities. Nearly three-quarters of detainees who had driven after using cocaine reported that being under the influence ‘never’ affected their driving; 68 percent of detainees who drove after using cannabis and 59 percent who drove after using amphetamine/methylamphetamine shared this view.

High rates of driving under the influence of alcohol or drugs were observed, despite the fact that the majority of detainees reported that being under the influence had a negative impact on their driving ability.

While half of the amphetamine/methylamphetamine using drivers who reported an impact on their driving ability said it was ‘negative’, worryingly, 22 percent reported that it actually had a positive impact. Similarly, 15 percent of cannabis using drivers who reported an impact stated that it was positive. Alcohol was reported to have a negative impact on driving ability by 60 percent of drivers. Despite public education on the impacts of drink driving, nine percent reported an improvement in driving ability when under the influence of alcohol.

Of those detainees who had driven a vehicle in the preceding 12 months, 249 (21%) reported that they had failed to stop when requested by the police. Male detainees were more likely to report failing to stop for police than female detainees (22% vs 12%).  

While only a relatively small number of detainees (95 individuals) reported being involved in a high-speed pursuit in the previous 12 months, more than one-half of these self-reported being under the influence of amphetamine/methylamphetamine (57%) at the time of the pursuit. These findings are consistent with past research, which links the effects of amphetamine/methylamphetamine and the propensity for some individuals to become involved in aggressive driving behaviour, such as police pursuits. It has been suggested that amphetamine/methylamphetamine users may be attracted to police pursuits for the same reasons they use the drugs—a desire for excitement and risk-taking behaviour. In addition, 41 percent of detainees involved in high-speed pursuits reported being under the influence of cannabis and 29 percent under the influence of alcohol at the time of the pursuit.

The AIC is again looking at drug driving attitudes using new data collected through Drug Use Monitoring Australia Program and will report findings in the new year. Other relevant information may come from the 2013 AIHW National Drug Strategy Household Survey, which is expected to be released in late 2014.

Posted: 14 August 2014 | | | | | |