Alcohol, drugs, fatigue and fitness to drive
This domain tests blunt facts: alcohol and drugs impair judgement before you notice, and fatigue is a physical state you cannot talk yourself out of. The exam expects you to recognise the warning signs and to have a personal rule that keeps you out of the driver's seat.
Alcohol
The legal limit is low - of the order of 0.5 g/L of blood - and novice and professional drivers are usually held to a stricter standard. Alcohol is absorbed quickly and eliminated slowly, roughly 0.10 to 0.15 g/L per hour. Nothing speeds that up: coffee, a cold shower, food and fresh air only make a drunk driver feel more alert. Even small amounts lengthen reaction time and narrow attention.
Drugs and medicines
Illegal drugs are incompatible with driving and are treated severely. Prescription medicines can be just as dangerous: read the pictogram on the box. A level 2 or 3 warning means do not drive without medical advice.
Fatigue
Warning signs include heavy eyelids, drifting in the lane, missing signs, yawning and irritability. The remedy is a break of 15 to 20 minutes every two hours, and sleep. Do not nap on the shoulder of a busy road; leave it at a proper stopping place.
Fitness
Eyesight must meet the required standard; wear glasses or lenses if your licence says so. Do not drive with a fever, after a sleepless night or while taking sedating medicine, and declare conditions that can cause loss of consciousness.
Worked example
You drank four beers at a wedding and stopped three hours ago. You feel fine and the trip is short. Elimination is still incomplete, so you are probably over the limit. The only safe and exam-correct answer is not to drive.
Traps that cost marks
Trusting I feel fine; using energy drinks to push through fatigue; believing a heavy meal sobers you up; assuming a short trip carries no risk.