The three-day initiative announced is part of the Crime Braker campaign.

It will see the Northern Constabulary and Grampian forces focus on drug misuse on Scotland's roads.

Police also handed over drug-driving leaflets to the Aberdeen Nightclub Association to distribute among clubbers as part of the offensive.

During the campaign officers will stop drivers to examine their eyes to check if the pupils are constricted or dilated.

Officers will also ask drivers to:

• Demonstrate their balance and perception by estimating the passing of 30 seconds

• Walk and return for nine paces in a straight line

• Stand on one leg for 30 seconds

• Touch the end of their nose with the tip of their index finger.

Grampian Superintendent Dave Cormack said the aim of the campaign was to drive home the message that taking drugs and driving was a potentially lethal combination, with heavy penalties.

"Research by the Scottish Executive tells us that drug driving is a problem particularly among the 20 to 24-year-old age group and more often among young men," he said.