Fifteen Hours Awake, Two Beers and a Cold Remedy
You woke at 03:30 after about 3,5 hours' sleep and have been driving since 04:30. It is now 19:45 and you are 60 km from home with a 300 km day behind you. You ate once, at about 10:00, and have been drinking energy drinks since. At 05:00 you took a cold remedy containing codeine and chlorpheniramine, and you took a second dose at 15:00. At a late lunch around 14:00 you had two beers. Your co-driver, who slept well last night, offers to take over but holds only a Code 3 learner's licence. At a roadblock your breath test reads 0,13 mg per 1 000 ml.
1. Assess this driver's fitness to drive at 19:45, separating the fatigue factors from the drug factors and explaining how they compound.
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Fatigue load: awake since 03:30, so roughly 16 hours by 19:45, on 3,5 hours' sleep - a sleep debt of four to five hours carried into a long drive. Concentration and reaction time at 16 hours awake are measurably degraded, and the circadian low between roughly 14:00 and 16:00 has already passed with him still driving. One meal and a stream of energy drinks gives a caffeine spike followed by a deeper trough.
Drug load: codeine is an opioid that causes drowsiness, slows reaction and dulls judgement; chlorpheniramine is a sedating first-generation antihistamine whose effects last many hours - the 15:00 dose is fully active at 19:45. Both carry explicit warnings that driving is affected. Add two beers at 14:00 and you have a central nervous system depressant stacked on another depressant on top of a sleep-deprived brain.
Compounding: these do not add, they multiply. Fatigue reduces the ability to notice that you are impaired, which is exactly the faculty you need to make the decision to stop. The honest assessment is that this driver should not be behind the wheel at all, and has probably not been fit since mid-afternoon. The energy drinks are masking the symptom, not treating the cause.
2. What is the legal position on the 0,13 mg reading, on the medication, and on the co-driver's offer to take over?
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The reading: for an ordinary driver the limit is 0,05 g per 100 ml of blood, equivalent to 0,24 mg per 1 000 ml of breath. For a professional driver - a PrDP holder - the limit is 0,02 g per 100 ml, equivalent to 0,10 mg per 1 000 ml. At 0,13 mg per 1 000 ml you are under the ordinary limit but over the professional one. Since you are driving a heavy vehicle and may be required to hold a PrDP, assume the stricter limit applies to you and confirm it before you argue otherwise. Refusing a blood sample is itself an offence.
The medication: alcohol is not the only route to a charge. Driving while under the influence of a drug with a narcotic effect, or while incapable of driving properly, is a separate offence, and the codeine and sedating antihistamine in your system support it. A reading under the threshold does not make an impaired driver legal.
The co-driver: a learner may not drive unaccompanied. A Code 3 learner needs a properly licensed driver for that class seated beside them, and that licensed driver would be you - impaired. The offer solves nothing; it just moves the offence to a different seat.
3. Set out what should have happened differently from 03:30, and what you do now at the roadblock.
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From 03:30: the day was lost at the planning stage. A driver starting a 300 km route on 3,5 hours' sleep is a scheduling failure, not a personal one. The correct actions were: report unfit for duty and let the operator find a rested driver; do not take sedating cold medication and then drive - ask for a non-sedating alternative or stand down; if you must travel, plan a proper break every two hours with a 15-minute stop, not an energy drink in the cupholder; and never drink at a mid-route meal when you still have to drive, whatever the professional threshold is.
Now, at the roadblock:
- Be honest and cooperative. Arguing about which limit applies converts a bad night into a bad case.
- Do not attempt to drive on. Arrange for a licensed, rested driver or for the vehicle to be collected; a heavy vehicle left at a roadblock is a problem for the operator, not a reason to move it.
- Get the matter documented and tell your operator immediately, because the licence consequences flow to them as well as to you.
- Accept that the vehicle stays put. The 60 km home is the most dangerous 60 km of the day - the last stretch of a long drive on a familiar road is where fatigue collisions cluster.