Which types of evidence are important to prove impairment under the unfit to drive offences?

• A. Blood test results alone
• B. Field sobriety tests only
• C. Witness statements only
• D. Doctors’ opinion and officers’ observations

Answer: (D)

Impairment for unfit to drive offences hinges on showing the person was not capable of driving safely because of a medical or physical condition. A doctors’ opinion provides a professional assessment of whether that condition is likely to impair driving at the time, giving medical credibility to the claim. Officers’ observations add practical, on-scene evidence of how the person behaved and performed—signs like poor coordination, slowed reactions, slurred speech, or general wobbliness that indicate real impairment in a driving context.

Blood test results only show what substances are present or their levels, not whether those substances were actually impairing driving at that moment. Field sobriety tests can indicate impairment but aren’t definitive on their own and can be influenced by many factors. Witness statements alone can be unreliable or nonspecific about actual driving ability.

So, combining a medical opinion with the officer’s contemporaneous observations gives a robust, credible basis to prove impairment for these offences.