Driver Fitness, Fatigue, Alcohol and Drug Rules
What this domain tests
Whether you can judge your own fitness to drive and know the legal limits on alcohol and drugs - the domain where a single wrong answer in real life ends in a fatal crash or a court appearance.
Medical fitness
- Vision must meet the standard for the licence class; if you need glasses to pass the eye test, you must wear them while driving.
- PSV and commercial drivers undergo periodic medical examinations, and must declare conditions such as epilepsy, diabetes, heart disease or severe hearing loss that could affect control of the vehicle.
- Prescription and over-the-counter medicines that cause drowsiness are a real impairment - check the label and ask the pharmacist before driving.
Alcohol and drugs
- Kenya's statutory limit is 80 mg of alcohol per 100 ml of blood (0.08% BAC); exceeding it, or refusing a specimen, is an offence with heavy penalties and licence consequences.
- Alcohol impairs judgement and reaction time long before you feel drunk, and the body clears it only with time - coffee, food, cold air and energy drinks do nothing.
- Driving under the influence of cannabis, miraa, cocaine or other drugs is illegal on the same basis as alcohol.
Fatigue
Fatigue causes micro-sleeps that you cannot fight. Plan breaks, share driving on long hauls, avoid driving through the small hours, and stop at the first signs: yawning, heavy eyes, drifting, missing signs. A 15–20 minute nap is more effective than any stimulant.
Worked example
A driver finishes a 12-hour day and is called for a night run. He has had two beers with supper. He should refuse the trip: the alcohol is still in his system, his fatigue is significant and the combination is far worse than either alone.
Traps that cost marks
Believing coffee sobers you up, assuming "two beers" is under the limit, and driving on antihistamines because the label was not read.