Fitness to drive (alcohol, stress, illness, sleep) – Road Traffic Act §21

You may only drive when you are fit to do so. This article summarises key fitness factors and what the law expects.

Key areas

• Alcohol and drugs: obey limits and medicine warnings
• Fatigue and sleep: do not drive when drowsy; plan rest
• Illness and temporary impairment: postpone or choose alternatives
• Stress and emotions: reduce load and add buffer time

Legal basis

Road Traffic Act §21 requires drivers to be fit to drive. Violations can lead to punishment and liability. See also Alcohol, BAC limit and drugs .

Practical guidance

• Do a brief self‑check before every drive
• If in doubt, do not drive
• Ask a professional (doctor/pharmacist) when needed