Fatigue, alcohol residue and a night drive home
It is 23:30. You have been at a wedding since 18:00, drank two glasses of wine between 19:00 and 20:00 and nothing since, and ate a full meal. You feel tired but 'fine'. The drive home is 70 km, mostly motorway, after a full working day that began at 06:00. You slept only about five hours the previous night. A friend offers to drive but has a category B licence held for eight months and would be driving your car, which is insured for 'named drivers only' with you as the sole named driver. You estimate your blood alcohol is 'probably under the limit by now'.
1. Assess your fitness to drive, covering alcohol, fatigue and the legal position in Austria.
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Feeling 'fine' is not the test. In Austria the general alcohol limit for ordinary drivers is 0.5 g/kg (0.5 per mille) blood alcohol, and for novice drivers in the probationary period and for professional drivers it is effectively 0.1 g/kg - practically zero. Even if two glasses of wine five hours earlier might leave you under 0.5, elimination is slower than people think (roughly 0.1 to 0.15 g/kg per hour) and cannot be rushed by coffee, food or fresh air. More importantly, your fatigue is a separate and serious impairment: a 06:00 start, about five hours' sleep, a long evening and a 70 km night motorway drive is a classic microsleep scenario. Tiredness slows reaction and reduces attention, and the risk rises sharply at night. The safe and lawful decision is not to drive. I would take a taxi, use public transport, or stay overnight, and collect the car the next day. If I had any doubt about alcohol, I would not drive at all - the limit is a ceiling, not a target.
2. Can your friend drive your car home instead? What must be checked first?
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Not automatically. Three things must line up. First, the licence: a category B licence held for eight months is valid, but the friend is in the probationary period, so the stricter near-zero alcohol limit applies to them - they must be completely sober, which rules out a night out. Second, the insurance: the policy names only you, so the friend is not covered unless the insurer extends cover; driving without valid cover is an offence and leaves you personally liable for damage. Third, the car: the friend must be fit and familiar enough with it. If the insurer confirms cover and the friend is sober and rested, letting them drive is sensible and removes the fatigue risk. If cover cannot be confirmed at 23:30, the correct answer is a taxi or an overnight stay, not an uninsured drive. I would also check that the friend's licence has no restrictions that affect driving this car.