There were almost 700 cases of people driving under the influence of both cocaine and cannabis last year.
A 13-year-old and a 95-year-old were among those who were arrested for drink or drug-driving in 2021.
The Medical Bureau of Road Safety received just under 5,900 blood and urine samples for alcohol and/or drug testing last year.
Alcohol was the most frequently detected - and one driver was found to be over eight times above the legal limit.
Of 4,300 samples tested for drugs last year, over 3,400 were found positive for at least one substance.
Of those, 36% detected at least two drugs, with cannabis and cocaine the most common combination.
Other than alcohol, the most commonly detected substance was cannabis, followed by cocaine and benzodiazepines.
There were 140 cases of drivers having all three of these drugs in their system.
There were over 40 cases of drivers with four drugs in their system last year.