Along the A28 near Deventer the police stop a driver who has used drugs and alcohol. The test measures a small amount of both substances. The driver says: 'For each substance I am still under the normal limit.' What applies?
He is not punishable: each substance is checked separately against its own normal limit
He is only punishable if at least one substance goes above its own normal limit
He is punishable after all: with drugs and alcohol together each substance has a zero limit
Explanation
False — you think one substance must first go above its normal limit. With drugs and alcohol together, the lowest measurable amount of each substance is already the limit, even if neither substance reaches its normal limit (book p. 17).