Driver Fitness, Fatigue, Alcohol and Drug Rules
What this domain tests
Driver fitness, fatigue, alcohol and drug rules tests whether you can recognise when you are not fit to drive and know the legal limits that apply to you.
Alcohol
- The legal limit is 0.05 % blood alcohol. For a professional heavy-vehicle driver the practical and expected answer is zero.
- The body clears alcohol at roughly 0.015 % per hour; nothing - coffee, cold water, food, a shower - speeds that up.
- Refusing a breath test is treated as an offence.
Drugs and medication
The law prohibits driving under the influence of drugs. Many legal medicines - sedating antihistamines, strong painkillers, some cough syrups - impair you as much as alcohol. Read the label and ask the pharmacist; if it says do not drive, do not drive.
Fatigue
- Fatigue crashes are the ones where nobody brakes. Warning signs: yawning, heavy eyes, drifting, missing signs, not remembering the last few kilometres.
- Take a break at least every two hours; a 15–20 minute stop with fresh air and a short sleep beats an energy drink.
- Do not start a long run after a full shift or at the hour you normally sleep.
- Sleep apnoea, uncontrolled diabetes and epilepsy affect fitness; declare them at your medical.
Fitness and medical
A heavy-vehicle licence requires a medical certificate at issue and renewal. Eyesight, hearing, blood pressure and any condition that can cause blackouts are checked.
Worked example
For an average build, four standard drinks over an evening might read 0.08 % at midnight. At 0.015 % per hour, by 6 a.m. you are still around 0.05 % - at or above the limit. The safe plan is a driver, a taxi, or sleep.
Traps
Judging fitness by how you feel; assuming black coffee sobers you; ignoring the warning on a prescription.