There was a time when drinking and driving was acceptable. It provided gag material for comedians but, beyond that, the issue didn't really register strongly in the national consciousness.
The advent of the breathalyser, more diligent and consistent enforcement of the law and a series of high-visibility, national road-safety campaigns eventually transformed driving under the influence of alcohol from joke to pariah.
Even now, there are areas of confusion concerning the topic of driving and alcohol. Few people know the legal blood-alcohol limit for drivers, or what that limit equates to in terms of glasses of wine or pints of beer. Small wonder, then, that the situation with driving after using other drugs is even more of a mystery to most people.
Under the radar
Where the profile of the drink driving problem is high, and receives a seasonal boost around every Christmas when police forces launch annual awareness and enforcement campaigns, drug driving remains in relative shadow. Many people aren't even aware that there is a specific problem or offence known as drug driving. Even fewer people know what constitutes drug driving.
In a way it is understandable. Even though common sense should tell us that alcohol isn't the only drug that can adversely affect our ability to drive, how are people to know which of the countless legal and illegal substances they may encounter can present a drug driving hazard?
The relatively low awareness of drug driving does not reflect a low incidence. In fact, some police forces have reported that levels of drug driving may have equalled, or even surpassed, those of drink driving. Merseyside Police has said that it regularly stops more people impaired by drugs than drink, and the National Police Chiefs Council (NPCC) has released data showing that during a campaign in England and Wales, 48.5% of drug tests were positive, while 9.5% of breath tests for alcohol were positive.
So what exactly is drug driving?
One reason that the drug driving picture seems unclear is that there isn't a nice simple definition. Drug driving can mean driving while impaired by the use of prescribed drugs and/or driving while impaired by illegal drugs. There is an official list of controlled substances and each substance on the list has a limit on its permissible concentration in a Driver's blood, much the same as with alcohol. Sections 5A(1)(b) and (2) of the Road Traffic Act (RTA) 1988 provide for an offence of driving or being in charge of a motor vehicle with a proportion of a specified controlled drug above the specified limit.
However, that's not the whole story, and driving while impaired by any drug, whether it is on the controlled list or not, is an offence. If police suspect that a driver's competence is compromised by drug use, they may charge the driver under Section 4 RTA 1988 - Driving/Attempting to drive or being in charge of a motor vehicle whilst unfit. A charge under this section may be made, even if the drug concerned is legally prescribed and below the blood concentration limit. It is the impairment to driving ability that is important.
What are the drugs specifically addressed in the legislation?
The following is the government's published list of drugs and their permissible blood concentration limits for driving.
NB: Remember that the following are just the substances for which limits are published. Other drugs may also render a driver subject to prosecution. Also, even if the permitted limit is not exceeded, it is still an offence to drive if the substance has affected your competence to do so.
| 'Illegal' drugs ('accidental exposure' – zero tolerance approach) | Threshold limit in microgrammes per litre of blood (µg/L) |
|---|---|
| Benzoylecgonine | 50µg/L |
| Cocaine | 10µg/L |
| Delta-9-Tetrahydrocannabinol (Cannabis) | 2µg/L |
| Ketamine | 20µg/L |
| Lysergic acid diethylamide (LSD) | 1µg/L |
| Methylamphetamine | 10µg/L |
| Methylenedioxymethamphetamine (MDMA) | 10µg/L |
| 6-monoacetylmorphine (heroin) | 5µg/L |
| ‘Medicinal’ drugs (risk based approach) | |
| Clonazepam | 50µg/L |
| Diazepam | 550µg/L |
| Flunitrazepam | 300µg/L |
| Lorazepam | 100µg/L |
| Methadone | 500µg/L |
| Morphine | 80µg/L |
| Oxazepam | 300µg/L |
| Temazepam | 1,000µg/L |
| Separate approach (to balance its risk) | |
| Amphetamine | 250µg/L |
What are the penalties for drug driving?
A conviction for drug driving incurs some pretty nasty penalties and wider consequences.
The direct, legal measures can include:
- a minimum 12 month driving ban
- a licence endorsement lasting 11 years
- a criminal record
- up to 6 months in prison
- an unlimited fine.
If you have an accident and/or people are killed or injured due to the effects of drugs then the penalties increase in severity, even to the point of a potential life sentence.
Wider consequences of a conviction can include:
- increased insurance premiums
- humiliation and stigma of a conviction
- possible loss of employment
- loss of independence and mobility; the need to rely on lifts and public transport
- future difficulty in obtaining employment: employers don't like the word 'drugs'
- possible difficulty in getting visas or work permits for some countries due to the drug offence.
Drug driving myths busted
As with drink driving, there are a number of common myths about drug driving that have the potential to mislead drivers into breaking the law. Some are easy to debunk: others are worryingly plausible. Here are some of the more common, along with the actual facts.
The police only charge you for drug driving if you've used illegal drugs.
Complete nonsense, but still one of the most widely held misconceptions. We have explained above that the range of substances that can get you into trouble is very broad and includes both legal and illegal drugs. The police will enforce them all.
Driving on drugs is safer than driving after a few beers
Just as intoxicated people are often unfit to judge how much alcohol has affected their ability to drive, people under the influence of other substances are often similarly unable to objectively assess their condition.
It doesn't matter whether your drug is alcohol or cannabis: if you fail a roadside competence test or a blood test, you'll pay the price. If you consequently have an accident, you and others may pay an even higher price.
Cannabis doesn't affect your ability to drive
Evidence and the law beg to differ. But whether or not one accepts that driving ability is diminished by cannabis consumption, the law has decided that it is an offence that may carry the penalties listed above.
I'm safe if I'm not actually in the car when the police approach me, or if I sit in the back to sleep it off
No, you really aren't. If you have the keys or whatever is required to start and drive the car and you test positive for drink or drugs, you can be prosecuted for being in charge of the vehicle while impaired. The penalties for being "in charge" are slightly different from those for actually driving, but you're still looking at disqualification, licence points, a big fine and, potentially, a prison sentence. If you have control over use of the car, then you don't want to be anywhere near it after drinking or using drugs.
If I use drugs on a night out, I can go back and collect my car in the morning
Not necessarily. The effects of drugs vary from person to person depending on many factors including age, sex, body mass, metabolic rate and more. It is perfectly possible for blood to still contain a higher than legal drug concentration for driving the next morning, or even longer than that.
Police can't test me for drugs without a warrant
Oh, yes they can. Furthermore, they can arrest you for refusing to take required tests, which is an additional offence in its own right.
If I pass a roadside impairment test, police can't make me take additional tests or give samples
Oh, yes they can. See above.
I can cheat the police's test equipment by sucking mints/drinking a lot of water/eating a big meal before going out/using mouthwash/drinking coffee/swilling my mouth out with water before they see me etc
Good luck with that. Plenty of people have found these hacks to be completely useless. The DrugWipe kit used by UK police can test saliva, sweat and skin for traces of cannabis and cocaine. If the police have cause to suspect the use of other drugs, you can be taken to a police station for further testing.
Bottom line
It's not our place to tell people whether or not they should use alcohol or other recreational drugs. It's not our place to comment on how you take your prescription meds. However, we do see it as part of our job to share fact-based motoring advice and information: that is what this article is intended to do.
