A heavy vehicle driver is tested positive for drug presence by a roadside drug test. What is the legal consequence?

1. A formal caution only for a first offence
2. The driver may be required to submit to a laboratory blood/oral fluid test, and if confirmed, faces licence loss and penalties
3. Only the operator faces penalties; the driver is exempt if they did not know they were impaired
4. No penalty if the drug was prescribed by a doctor