Drug Driving: The Law Professional Drivers Cannot Afford to Guess At

Drug driving law has a trap in it that drink driving law does not: you can break it while feeling completely sober. GOV.UK’s guidance sets out two separate ways to commit the offence - driving unfit through drugs, and driving with certain levels of illegal drugs in your blood even if they have not affected your driving. For professional drivers, the second limb is the one that ends careers without warning.

The two offences

Unfit through drugs. It is illegal to drive if you are unfit to do so because of legal or illegal drugs. “Legal drugs” means prescription and over-the-counter medicines, and the guidance’s advice to anyone unsure is direct: talk to your doctor, pharmacist or healthcare professional.

Over the specified limit. It is also an offence to drive with over the specified limits of certain drugs in your blood - for illegal drugs, whatever the effect on your driving, and for listed medicinal drugs, if you have not been prescribed them. Some drugs linger in the blood for days, long past any feeling of effect. A driver can feel sharp, pass every self-check, and still be over the limit from the weekend.

Police powers at the roadside

The enforcement machinery is simple and fast. Police can stop you and make you do a field impairment assessment - a series of tests such as walking in a straight line. They can also use a roadside drug kit to screen for cannabis and cocaine. If officers think you are unfit to drive through drugs, you will be arrested and required to take a blood or urine test at a police station, and a charge follows if the test shows drugs.

Note what is missing from that sequence: any need to prove your driving was bad. The swab and the blood test do the work.

Prescription medicines: the defence with conditions

In England, Scotland and Wales it is illegal to drive with legal drugs in your body if they impair your driving. For a specified list of medicines - including amphetamine-based treatments, clonazepam, diazepam, lorazepam, methadone, morphine and opioid-based medicines such as codeine, tramadol and fentanyl, oxazepam and temazepam - the position is more nuanced:

• You can drive after taking them if they were prescribed, you followed the healthcare professional’s advice on how to take them, and they are not making you unfit - even if you are above the specified limits.
• You can be prosecuted for driving with them in your body above the specified levels if they were not prescribed to you.

Three implications for drivers. First, keep medicines in their pharmacy packaging and know what you are taking. Second, “a colleague gave me a tramadol for my back” is not a defence; unprescribed means unprescribed. Third, the medical defence depends on following the advice - doubling a dose destroys it. The law does not cover Northern Ireland in the same form, but drivers there can still be arrested if unfit to drive.

The penalties

Conviction for drug driving carries:

• a minimum one-year driving ban
• an unlimited fine
• up to six months in prison
• a criminal record

The conviction stays visible on your driving licence for 11 years, which for a professional driver is most of a working lifetime. Causing death by careless driving under the influence of drugs carries a maximum of life imprisonment. And the knock-on effects run further: insurance costs rise significantly, an employer sees the conviction on the licence, and travel to countries like the USA can become a problem.

The operator’s position

Fleets need a drugs policy that covers both limbs of the law:

• Say both halves out loud. Unfit means unfit, from any substance. And over-the-limit means over-the-limit, however fine you feel.
• Prescription disclosure with no penalty for honesty. Drivers on listed medicines need a safe route to flag it, get occupational advice and be reassigned if necessary - before a roadside swab does the flagging.
• The weekend rule. Because some drugs persist in the blood, the policy has to reach into private time, which is exactly why it must be explained plainly rather than discovered at a police station.
• Induction and refreshers. The roadside kit tests for cannabis and cocaine on the spot; drivers should know that before they ever meet one.

Drug driving law is written to catch the driver who judges themselves fit. The only safe judgment for a professional driver is the one made before the keys come out.

Sources

• Drugs and driving: the law (GOV.UK)