A HGV driver from Gwynedd has been arrested as part of Christmas anti-drink and drug drive campaign.
North Wales Police said the driver was stopped on the A5 at Ogwen.
The 20-year-old who is from the Bala area tested positive for cocaine but was also driving without a licence, insurance and MOT.
He was released under investigation.
A police spokesperson said: “If you suspect someone is driving while unfit to do so, please report it immediately to police on 101 (or 999 if they are posing imminent danger) or phone it through anonymously to Crimestoppers on 0800 555 111.
“Your calls really do make a difference.”
You can follow the North Wales Police campaign on social media by following the #Fatal5 and #OpLimit hashtags.