Surveyors made friendly approaches to all drivers purchasing gas at a service station and entering a supermarket. Initial wariness was overcome by quickly providing identification on approach and running through the consent form, which reinforced privacy measures.

Subjects who signed consents, with non identifying squiggles if they wished, were provided with a private environment where the Oraline saliva testing tool was explained, where they were supervised to drug test themselves, and where a multi choice and open ended question survey questionnaire was completed over 5-10 minutes. 

The test used was the Oraline, which meets SAMHSA guidelines and has overcome the main difficulties of insensitivity and potential contamination of earlier testing technology. Results were not confirmed by GCSM lab testing.

Results Summary  

1. General drug usage and impaired driving behaviour patterns  

The daytime prevalence of drug affected driving as was represented in our sampling (bias to lower socio-economic) was 13% (20 male/6 female drivers) which may be generalised to prevalence rates in lower socioeconomic catchments of between  8.3%-17.7%  (95% confidence interval).
80 subjects who have been drug users tested negative for impairing recent drug use who were mostly (60) current users.  One test was negative when the subject reported light cannabis intake that was recent - this may have been due to an inadequate testing technique by an inexperienced worker.

Thc 23 cannabis detections and 3 sole use of opiate ones constituted the only drug detections. Methamphetamine was notable by it's absence,  given that as many as 15 subjects (7%) reported non recent use. Surveyors noted several people (3-5) amongst those who declined participation had displayed the physiological signs of stimulant intoxication.

Incidence of past or present drug use in the sample group showed no sex bias and was commonest in the under 25 age group with 37 of 52 acknowledging use. 43/58 subjects in the 25-40 age group acknowledged use illicit drug use, more often historic than in the younger group. The majority of drivers > 40 had never used recreational risk drugs or no longer did so. 61/93 people (68%) versus this age group constituting just 25% of the subjects in the user group (27/106). This <40  older age group also had a relatively high representation of non drinkers (22 subjects ). Only 3 of the drivers returning positive test results were > 45. Drivers that tested positive for drugs during the survey did not directly reflect the general usage trends found, being predominantly male and under 35. 

Self reports of participants who admitted to driving following risk drug use revealed a sharp decline in both DUID incidence and frequency of the hazardous behaviour (where it did persist), commencing at around the age of 25. This occurred despite the incidence of drug use in the cohort failing to diminish markedly until the age of 40. Only  9/37 drug users < 25 years of age reported that they would "never" DUI of traffic risk drugs. Half the of the 25's-40 yr olds (21/43) claimed no current DUID offending.  20/26 older users said they never DUID.

People self reporting that they currently drive UI drugs on a regular basis (daily to weekly) were concentrated in the male group, age <25. Just under 50% (25) of the 52 survey subjects aged <25 said they would sometimes drive while drug affected. This was an over representation within the 61 total subjects who would sometimes drive drugged.  

Over a third (10) of those testing drug positive were under 25,  which was disproportionate given this age group constituted only ¼ of those surveyed. Heavy rather than regular use more greatly predisposed youth to be among the drug +ve drivers. 80% of the young THC positive group reported last use was heavy (over 1 joint) with 60% of the +ve group saying they "spot" (use class B THC). 

Fewer of those testing positive (60%), than those users who did not, used regularly. Of young drug users aged <25 who did not test positive for saliva drugs, 56% reported that their last THC dose was heavy, and 72% indicated regular use (more than monthly).

All drug +ve youth drivers reported having smoked cannabis while driving compared to  5/10  reporting drinking behind the wheel. Asked whether using drugs tended to increase typical alcohol consumption under half had formed opinions. 54 subjects disagreed (no difference), 20 agreed and 3 said it was the reverse.

2. Locus of harm 

6/10 drug positive drivers aged <20 had been the driver in crashes serious enough for a vehicle to be towed, including one being involved in a double fatality. An even higher rate of crash involvement was associated with being a person who "spots" cannabis oil rather than one who smokes, though the small numbers surveyed means no statistical significance can attach to this observation. 

3. Comparison of drug user driving histories with control group 

Of 106 drug users our researchers interviewed 26 had been the driver in a  crash serious enough to cause injury or result in a vehicle being towed from the scene. Drug users who'd crashed amassed between them 51 such incidents; 27 factored use of risk drugs by the driver interviewed.

Over half of the drivers testing positive had experienced a reasonably serious crash and/or had a serious traffic conviction. Under 20% of drug users who did not report ever driving drugged had ever experienced an endangering crash (4/22). A third of subjects who reported ever having driven drug affected had been involved in a crash from which a vehicle was towed (28/81). 

As a group drug users had  2 x the rate of serious traffic offences of the type likely to lead to injury or death than that of non drug users (29 convictions / 89 ppl). The total number of drug related crashes for the class A/B + C poly-drug driving group at 20 people, was approximately 50% higher than the total number of alcohol related crashes (13) for the Class A or B plus C drug using part of the sample group. Some crashes (8) involved both alcohol and drug use.
12 of the 26 drug using crashers  (6% of the random sample) claimed they had felt drug affected during one or more of their reported crashes. 3 of the 12 were women (all aged under 35) and 2 of these women used harder drugs atop the garden varieties more typically used of THC & ETOH. 5 of those who had seriously crashed while affected by risk drug use said they spot cannabis oil.

Crash involved drug drivers between themselves reported having 18 serious crashes while under influence of solely drug use, 9 crashes under influence of both drugs and alcohol and 4 crashes involved sole use of alcohol. This equates to 60% of all surviving drug users crashes involving risk drug/s, or less often alcohol effects. Or about half of drug users who crash (on average) likely being under the influence by self reports.

All who reported serious (defined as "towaway") drug impairment crashes used THC except for 2 who preferred class A and B drugs. One third of them reported current regular cannabis use. Nearly half (13) also use other illicit drugs (mainly P, Benzodiazepines or opiates) though only 4 reported regularly adding other drugs ie  frequency > monthly over the last year.

A minority of drug users (35%) who reported one or more crashes sometimes used Class A/B while a similar proportion (27/78) in the user group actually reported some hard drug use. 7 of the 12 people who reported having seriously crashed while drug affected (generally driving under the influence of THC +/- ETOH) reported they would sometimes drive under the influence of "hard" risk drugs. This constitutes 3.5% of the entire sample group.

Only 2 of the 7  "other" poly-drugging crash involved drivers who admitted to DUI "other"  drugs than THC or ETOH reported ever crashing UI alcohol.  Only 1 of the 2 who crashed while drunk said he'd solely used alcohol. 

Approximately half of the self reported drug crashers (which was that subset of 7 poly druggers using hard drugs) accounted for 25/32 known DUI crashes, though poly drug users constituted well under half of the total drug users. Polydrug drivers (using class A/B) were grossly over represented among both crashers and traffic offenders given they constituted up  30/103 of drug users but that they were 13 of the 28 crashers who used drugs, and held a  66% share of total traffic offences committed by all drug users (66/100).

Among the 76 non crashing drug users the total number admitting to ever DUI of other risk drugs (than THC or alcohol) was 9.  Risk taking by sometimes driving drug affected was reported by approximately half of both the using crasher and the non crasher user groups. The main difference was that crashers were more likely to say they never delayed driving than to say they always or sometimes did so on account of drug effects.

The subjects who had crashed UI drugs self reports regarding consumption at last use of alcohol or  drugs suggested a greater tendency to use drugs heavily (29%), than to use excess alcohol (17%). 9 of the 12 reporting drug impairment crashes used their chosen drugs (mostly THC) heavily at the last use before the survey, 6 of these drank heavily the last time alcohol was used. Of the 6 non drinking drug impaired crashers 3 reported using THC heavily at the last use. 58% of drug crashers reported last use was heavy.Those crashers who connected a crash they'd had to drug use on average reported a greater frequency of  driving impaired than drug users who had not had crash involvement. The average frequency of impaired driving by crashers was at least weekly, when that third of drug related crashers who no longer drive impaired was excluded.

Among the group reporting just DUI THC +/- alcohol (31 offences / 60 people) the averaged traffic offence rate was 1.5x higher than that of non drug users (26/89). The drug users who have never crashed mostly said they presently don't ever drive drugged (45/77). However of those who did two thirds said they would do so at least weekly. 

The male regular Class A/B +  THC users who'd crashed while drug impaired had extensive driving related convictions (average of  nearly 4  ie 58 convictions for 16 people)  versus the averaged number of traffic convictions of  <1 for drug impaired crashers who did not use Class A or B (excluding hashish); 10/14. This may be compared against an average number of driving convictions of  0.3  for people who only drink alcohol  25/79+1ex drinker. The number of sole THC users  was so insubstantial as to make any analyses of data in relation to their risks pointless.

4. Comparison of conviction rates 

44 of 106 drug using subjects reported serious driving convictions (range - careless, dangerous reckless, drink driving, race) with 85 total convictions shared between them. 21 had drink driving convictions. 18 of the 90 non drug users had serious driving convictions. 5 of the non drug users had a drink driving conviction. 

Convictions held by those admitting impaired to drug impaired driving by drug/s used; 
THC only – 4 convicted for offences out of 6 users
Both THC and alcohol – 19/57
THC and other risk drugs minus alcohol – 0/1
Everything users -16/29; all poly-druggers had driven impaired 

5. Passengers assessment of risk from drug drivers 

52 people had been asked to drive for the drunks due to their preference to use drugs instead, 44 had accepted.
55 people had been driven by drunks, 45 had been driven by drug drivers, and 75 by people people who were both drunk and drugged. Some people (22) fell into more than one category.

Almost all drug users had been driven by impaired drivers and they had suffered the most in DUI crashes experienced as the result of being passengers. 18/103 who had been at risk passengers ended in a DUI crash as a result (38 crashes ='s average of 2 in this circumstance each) versus 7/89 non drug users being passengers in DUI crashes (one was over 20 x due to a recidivist partner).

6. Drug drivers risk assessment and decision making (risk to health and legal risk)

40 of the drivers who have driven drug affected reported that they never do so today. All prior drug crashers under 30 continued to drive impaired (bar one), but those in their thirties or older were split almost evenly between those still driving impaired and who did not.

The proportion of drug users that has used P (11) or cannabis while actually driving or on brief rest stops was 52% (56 people), 3 people had injected IV opiates during travel. 

Frequency of reported drug driving by current drug drivers; At least weekly (31), Monthly (8), Less often (7). 

Drug use co-related to excess collection of speeding tickets in youth – 12/37 drug users under 25 received speed tickets in the last year, and they received 33 tickets between them. 3 out of 3 young P users included. This rate compares to only one of the 15 non drug users under 25 only 1 was ticketed, once. 

Despite higher crash, traffic conviction and administrative offence rates the drug using subjects reported betwen them no convictions at all for drug impaired driving. 

7. General drug affects most often experienced while driving 

Drowsy / relaxed 42 reports, lost or miss turnoffs 21, visual deficits 16, time sped up 16, feeling invincible 15, forgetting seatbelt 13
The 28 drug users who had crashed reported experiencing 47 drug effects when driving between them, an average of 1.6 effects.
The 12  who recalled having used drugs prior to a serious crash had experienced an average of 2.6 drug effects with disorientation, drowsiness and visual effects being common. Drug users not reporting prior drug related crashes had only experienced an average of one impairing drug effect while driving.
Those using P or opiates tended to experience a broader raft of impairing effects than users of other drugs.

80% of those who had driven shortly after cannabis experienced impairing effects. Of the current THC users excluding concomitant hard drug users 70% reported noticing impairing effects. The rate remained constant among heavy, light, regular or irregular users.  2 sole THC users claimed no impairment while 6 others admitted to driving with one or more of; drowsiness, altered time sense and feeling bulletproof (reverse of most smokers  – fragile). A further 2 sole users (20%) said they never drove while affected.

Of the 81 current THC users 58 also drink alcohol (mostly not heavily) which can compound effects. 5 do not but use illicit stimulants, several  used a range of harder drugs and a similar number were mature sole users of THC who admitted to driving.

8. Strength of belief that drug drivers will get caught versus general population. 

41 of 81 total drivers who reported having ever driven under the influence of drugs in the survey reported having bypassed alcohol checkpoints while feeling impairing effects. Some people were unable to offer an opinion as to whether drug drivers would likely get picked up. In total 88 of the 181 who offered an opinion thought drug drivers had no chance of getting caught. For non drug users 50 thought that drug drivers probably would get caught but 35 thought not. By contrast among drug users themselves a minority (43 out of 108) thought they could get caught. But generally only after a crash, and many opined that a DUI charge was unlikely. 53 drug users thought people would not get caught for drug driving.

9. Non drug users; as passengers and their views of solutions (comments from open queries to all participants available by request)

33% of non drug users over 45 did not ever drink alcohol, unlike most younger non using subjects.
34 (38%) of the non users had been "driven by" impaired drivers versus  85/106 (80%) of users. Only 13 cases of non users being "at risk" passengers involved sole alcohol, so in 21 it had been drugs or both alcohol & drugs influencing their driver.
30 of the 34 strong non user DUI passenger group favoured use of saliva drug screens.

In the under 40 year old non drug users group it was a common at 52% (5/29) to have been a drug drivers passenger. Being driven by someone solely impaired on alcohol was rare at only 10% by self report in this age group  (3/29), though the experience was more prevalent in the older group at 17% (10/60).

7 of the 34 non users who'd been transported by an impaired driver had experienced a crash in that circumstance (8% of all non users)
19 of the 90 non drug users knew of friends or family having a DUI related crash of which; 9 attributed this to solely alcohol, 2 to solely drugs and 8 to both alcohol and other drugs (mostly cannabis), so drugs were anecdotally a more common factor.

74 people (82%) supported introduction of the full battery of interventions (Education, Enforcement, Saliva tests for screening), 5 were for education + saliva, 4 were for more enforcement and also use of the saliva test but no education,  2 thought just using saliva tests for screening purposes would do,  1 wanted just education, and 1 subject wanted no action citing alcohol as being the problem.

Discussion of findings in more depth

The findings revealed drug driving might be a mainstream, if disapproved activity in lower socioeconomic communities, which tend to be those hardest hit by road trauma. This may in part be an adverse outcome of having a heavy random breath testing program in such locations. Fundings concurred with the IMMORTAL study in showing polydrug driving to be an extreme risk, but differed in that they added further weight to the growing evidence base that cannabis is a large crash contributant, in some regions less conservative than Europe. 

This survey did not control for confounding variables in relating drug use or intoxication to crash or conviction history, so simple associations were demonstrated, that may suggest future avenues for research. No analyses of statistical significance was completed by the researchers, beyond the general drug driving prevalence findings may not safely be generalised to the full driver population, the bulk of results are best used to suggest areas of interest.

De Gier (ICADTS) has found that 20-30% of a population regularly use licit or illicit drugs that impair driving - our survey found 30% self reported some illicit drug driving, and just over half said this occurred daily to weekly. Prevalence of drug affected drivers accorded with recent U.S. roadside surveys of 600 subjects. Under reporting of drug related crashes by our subjects was likely as it is generally observed people can be impaired for driving, before recognising this. 

Impairment of a scope relative to raising crash risk is considered extant in methamphetamine users at any level. It is postulated to exist in drivers containing over 1ng of delta 9 thc in their blood but only becomes significant in crash statistics only at 3-5 ng or higher at typical time of driver testing (although , non prescribed opiates would typically impair more than prescribed resulting in apprehension or death due to manner of use (intoxication sought, fluctuating tolerance and blood levels , IV administration, potentiation with other drugs). For the purposes of this discussion it may be assumed that all subjects testing positive for risk drugs (Oraline indicates over 4 ng THC and no opiates were prescribed) were impaired.

Our finding of 13% drug impaired driving prevalence may compare unfavourably with Canada where only 5% of drivers report having driven within 2 hours of cannabis use, but is perhaps comparable to Scotland where a Glasgow University study of 1000 drivers found a 9% prevalence. and NewCastle, Australia which found a 10% prevalence (low end of our range). 

Random tests of typically around 1000 drivers in Germany, Denmark and Netherlands have found prevalence of cannabis use (which accounted for most of our cases) in general drivers were respectively 0.6%, 0.7% and 4.5%. More recently the 2005 Pilot Test of New Survey Methodology for Impaired Driving by the U.S. Dept. of Transport found that 7% of drivers tested positive for cannabis, using an oral saliva cut off equal to ours of 4 ng. This is infitting with the range provided by our survey. 

Candor consider the finding of significant daytime prevalence for drug driving was unremarkable - given that some U.S. crash data bases showing drug driving fatalities have a thicker daytime spread than drink drive ones, and given that research by the Ministry of Transport showing increasing risks of daytime road trauma within New Zealand. The policy of discretionary cannabis prosecutions has also perhaps contributed to our high prevalence, by creating a defacto legal cannabis use climate in the absence of regulation.

Of concern was that 49% of drivers under 25 admitted to having driven while drugged and 19% of those surveyed in that age group were actually driving drugged. Also 25 of the 92 who accepted rides from drug drivers reported resultant involvement in a crash

The profile of the NZ drug driver was of a male under 35 years old and more likely to amass speeding tickets than other drivers (prior year). This agrees with Canadian cannabis driver studies and Poyser et al (2002) who found a quarter of Australian traffic offenders were on methamphetamine. The higher rate of speeding among drug users also fits with the literature showing a lack of consequence and risk awareness after pot use, which may be accentuated by the risktaking nature of many drug users. The only robust study supporting the myth of the slow cannabis driver (a tenet of the increasingly debunked compensatory theory) was too small for generalising of results, and found the slowing reported in artificial conditions was of a degee insufficient to aid safety.

The problem ie crash prone New Zealand drug driver as sketched within our findings is likely to be a heavy cannabis dependent who drinks (1/3rds over a 6 pack a session) and drives drugged at least weekly. Or he/she is a poly-drug user who typically uses cannabis but also "hard" drug/s (often hashish) on occasion  or regularly, and alcohol may also be in their repertoire. He/she is more likely to have a prior conviction for drink driving offences than non drug impaired drivers, though unlike Norwegian drug drivers the majority of drug drivers did not possess a prior drink driving conviction. He or she rarely delays driving to allow drug effects to subside. The average age of the drug driver (30) reflects International trends (Vicroads analyses and others) and fails to coincide with the peak "clubbing" age. So at the age some drug drivers are divorcing driving from use, others are creating mayhem.

The impairing symptoms noticed by by drug drivers were fairly consistent across substances, and the typical cluster of relaxed or drowsiness, disorientation and visual effects are commensurate with fatigue and inattention being the most frequent factors listed in drug related crashes of young people that have perchance recorded in the Crash Analysis System. 

Hard poly -drug users were not so much over represented among already over represented drug users who have crashed seriously, though this subset tended to crash have crashed more frequently per member. One commented "I know it's illegal but I still do it (drug driving), because I can't help it". Alcohol checkpoint operations were not generally not viewed as obstacles by drug drivers - who even expressed that being let pass through was vindication of their skills. 

Findings of traffic difficulties were consistent with global data where illicit opiate users are found to be grossly over involved in crashes and impaired driving apprehensions versus cannabis users (also over involved). The Methamphetamine user group, among survey subjects had the worst driving
records of all subgroups – in strong association with poly drugging - but in sum total far more users of just cannabis had ever crashed than had members of the 7% who had used P.  Although the Australasian College of Police has expressed concerns about greater risk taking and poor visual acuity among methamphetamine using pursuit subjects, Marijuana intoxication has been demonstrated to give higher odds of being responsible in a crash than sole methamphetamine use (Drummer, 2004), and more often contributes to serious crashes per the literature. 

"The balance of evidence suggests that cannabis use puts drivers at increased risk of accident – particularly at higher dose" (NSW crime and justice bulletin), and there is a higher likelihood of youth (already prone to higher crash risk) driving under influence of cannabis. A potentially higher incidence of crashes due to cannabis use by youth in NZ than is caused by alcohol today, is a prospect also raised the finding of greater cannabis causation in crashes in a large cohort of youth in the Christchurch. 

It must be a concern that cannabis use is among the top predictors for youth crashing in the first years of their driving careers (Elliot et al, Asbridge et al). New Zealand's relatively high youth toll, with it's low co-relation to alcohol midst teenagers could well be contributed to by general complacency about cannabis harms, while local media have hyped the threats posed by methamphetamine or the relatively safer drug BZP. 

Given the high proportion of the using population willing or likely to drive shortly after cannabis as demonstrated by this survey, and the higher crash risk level attached to even sole thc use in the authoritative studies (Drummer 2004, Laumond 2005, Dussault), the proportion of injurious crashes in NZ yearly, which likely would not have occurred without gross thc intoxication being present (2/3rds of deceased cannabis +ves are over the critical 5ng if we follow Australian trends) must be substantial. 

A Ministery of Transport study by Frith et al showing a relatively exaggerated alcohol risk for young New Zealanders at any given alcohol level, taken in light of alarming risk ratios for cannabis/very low alcohol combinations that have just emerged, and of the NZ's deceased driver study showing lower BAC co-related to drug positivity and almost universal drink and/or drug involvement in a younger deceased drivers, indicates that adopting lower alcohol limits would be futile. Provided policy doesn't also target THC use by New Zealand drivers. 

The range of drugs used and/or frequency of driving impaired was more important than subject sex or even whether drug use was typically heavy in determining individual crash risk. Female sex was a less protective influence than studies have shown with alcohol use. 

Findings point to the presence of a hardcore of drug users who drive dangerously and are not deterred by survived crashes and may be encouraged by road policing strategies.  They also support presence of a larger "soft core" group with ill defined hazard awareness that also drives drugged with reasonable frequency.  Members of the second group may attempt to reduce risk by delaying travel. Members of the second group appear more likely to reduce DUID behaviour with age or bad experience despite ongoing drug use and are postulated to be a "thick end of the wedge" which could be targeted for life savings. 

A worthy part of the target audience for Public education may be approaching middle age and habitual not social users. For this reason, and acknowledging concerns raised about the term "recreational drugs" within the NSWs'  inquiry to harm minimisation policies we recommend that any drug driving campaign should seek to avoid use of the word "recreational" in association with illicit drug use. Harm to habitual and hazardous users is the target and few would call such a loss of control that so often part of an addictive process recreational 

A clear theme to emerge was that myths that abound regarding cannabis driving risk in the general population. Education to counter messages that have eroded safety is vital. More important than education is enforcement to achieve normative change in the target population. Various surveys have established that drug users would be unlikely to stop driving impaired without perceiving some risk of being thwarted by enforcement. The World Health Organisation has decreed that road safety education generally has low power to impact any targeted crash subtypes in the absence of enforcement.

A new technological process  was reported this year that can quickly (18 minutes), cheaply process saliva in the lab to evidential standards, largely removing the need for costly blood drug tests. Work by the U.S. Department of Transport is establishing whether speedier saliva tests correlate as well to blood levels of cannabis, as the initial trials suggest. Which would mean motorists could have confidence in saliva tests, and would only need to exert their right to blood testing with perhaps the same frequency that dubious drink drivers do. 

The United Nations Office for Drug Control Director Antonia Costa has lately recommended some system of drug tests for private vehicle drivers be adopted in member Nations, and other International Working Groups have also been making this recommendation in recent times based upon the large advances in testing technology. This survey's findings and other recent studies support that local prevalence and harm of drug driving would justify random drug testing of drivers under the age of 35 or 40 on Public Health grounds. The public acceptability of saliva tests was high among drug users and non users alike, though over 10 minutes to wait for test results was not considered ideal. The Countries that are drug testing have not faced or have defeated legal challenges. 

We recommend that any future program of random testing should not exclusively target the nightlife set but also the general younger half of the population, and that checkpoints run round the clock should add a drug test requirement for people under 40, on some occasions. Post incident or checkpoint saliva screen and evidential tests should be mandatory where there are general driving concerns, concerns a driver may be drug impaired or drugs are found in the  possession of an intending driver. 

Jones, Holmgren, Kugelberg (Addiction. 103(3):452-461, March 2008) however maintain that the notion of enacting science-based concentration limits of THC in blood (e.g. 3-5 ng/ml), would result in too many evading prosecution. The concentration of THC in blood at the time of driving is probably a great deal higher than at typical times of sampling (30-90 minutes later) given THC is metabolised quickly. Over a 10-year period they found that between 18% and 30% of all DUID suspects had THC in their blood > 0.3 ng/ml) and in cases with sole THC presence the concentration was below 2.0 ng/ml in 41% of cases. They concluded zero-tolerance laws are the most pragmatic way to enforce legislation.  

However, Candors researchers conclude that an adult sole use thc limit of 3 or 4-5ng should be considered, because a zero limit would unduly thwart adult user travel for up to 12 hours, despite a significantly raised impairment based crash risk for adults only being established for a few hours post use - and as saliva tests are only sensitive to levels relevant to impairment. We'd prefer to see a law that is workable within our high use culture, one that dedicates resources to higher risk areas, and one which can set some travel delay expectations that drug users will not see as Draconian and impossible. 

For Youth we would advocate a zero THC limit in light of both our local findings and of the relevant literature. There is a wealth of evidence  that cannabis use may well be especially hazardous to youth given it likely compounds greater issues with risk taking and hazard recognition that are extant due to the stage of brain development. We are confident cannabis is a major player in our high youth toll and that only a campaign of general deterrence can turn this round.

Historic research - archives

MEASURES  OF  SUCCESS  IN  DEALING  WITH  IMPAIRED DRIVING 

(Sorry - some  statistics are a  little stale as it is Government Policy to no longer record some major indicators)

Percentage of British drivers killed in all crashes while over alcohol  limit (similar in NZ)

Police DUI Enforcement And Judicial Response:

Findings of guilt by plea or 12 laymen for select offence groups NZ 1997:

In 2003 NZs Government...

in an apparent attempt to hide the increasing impact of drug driving on innocent people, reported intent to no longer collect / release statistics on criminal driving causing death. Rather to conceal them within the huge driving causing injury group so that their numbers can’t be known (offenders or a ballpark of their deceased victims). The following is quoted from an NZ Justice Dept Report "It is no longer possible to distinguish in the data between charges resulting in injury and charges resulting in death."

This means that when the road toll climbs, as benefits from progress made with drunk driving continue to be eroded, the role of intoxicated and deadly drivers will be hidden from us so Government can just blame the rest of us for poor driving. What would we think if murder convictions were lumped in with those for common assaults. The waters are already muddied (for victims trying to understand the situation) by the fact no breakdown statistics of how many killing drivers were intoxicated is even easily available. Candor believe concealing of such basic information is an act against a free informed society.

NZs  road toll is fairly static (odd spikes perhaps due to drug related multi-fatality crashes) but only because of huge pressure on drink drivers who now regularly have cars confiscated. All this excessive (by international standards) breath testing of responsible people has not made near as much of a dent as has that the small number of high risk incorrigible drink drivers are now well pegged following it plus the introduction of stronger laws / enforcement and often now disenfranchised of vehicle use and "on foot".

Like wise with the new breed (drug drivers), it will be law enforcement, firm penalty and intensive intervention to motivate change in addition to deterrent effect of random testing that will be most effective.

They hide among massive careless driving statistics, going unnoticed following small prangs, then sentenced to driving skill courses that don’t address but encourage their dui offending well before escalating into killers. We simply need to drug test as well as breathalise people who come to notice.

Average court penalties given for serious driving offences committed in 1997 in New Zealand.

COLLISION  SEQUELAE

  IN 2003 IN NEW ZEALAND THERE WERE...

                           single figure deaths by  AIDS

           46 deaths due to murder per  convictions            

                       Well under 100 deaths from Influenza

          461 died on NZ Roads (Or 1.65% of all deaths, over 1/2 of which occurred due to a  DUI crime)

The 2003 Study by NZ Environmental and Occupational Health Research Centre of Traffic Fatalities found that 77% of Road fatalities died at the site (half quite instantly), 3% en route to Hospital and 20% at hospital (usually happens within 30 days per UK study). Most were discovered within 5 minutes of the crash.

The first human fatality associated with a motor vehicle was a pedestrian killed in 1899. It is estimated that by the year 2020, 8.4 million people will die every year from injury, and injuries from road traffic accidents will be the third most common cause of disability worldwide and the second most common cause in the developing world.

In the European Brain Injury Consortium (EBIC) study, 52% of head injuries were related to MVAs. Head injury is a major cause of morbidity in survivors; disability may occur whatever the initial severity of the head injury and surviving patients with brain injury are more impaired than patients with injuries. In a study of nearly 3000 head injuries from Scotland, patients were stratified according to the Glasgow Coma Score (GCS) on arrival at hospital: mild, moderate and severe injury.

At follow-up after one year, 1397 were still disabled. Of these, 1260 (90%) had been initially assessed as mild injuries. Fatalities are only the tip of the DUI harm iceberg - many are affected for a life-time (at cost) though social and economic cost estimates of crash related harm tend to overlook this aspect.

Under construction