North Wales Police officers arrested 19 people in the first week of the Winter Anti Drink and Drug Driving Campaign. Of those arrests, 13 were made in relation to drink driving and six for drug driving.
The highest breath test reading of the campaign so far has been 146mg of alcohol per 100ml of breath - the legal limit is 35mg.
Inspector Dave Cust, from North Wales Police' Roads Policing Unit, said, "It is disappointing that a small minority of people are still intent on ignoring our messages, despite our repeated warnings.
"Just a week into the campaign, yet, 19 individuals have already been arrested on suspicion of driving under the influence of drink or drugs.
“Our #ChooseWisely campaign is heavily focused on asking people to make the right choice, so we will continue to use social media to drive home the messages that drink and drug driving can have devastating consequences.
“We have a robust strategy around enforcing the Fatal 5 offences which includes drink and drug driving and we are fully committed to making the roads safer for all. We will continue to target those who endanger their own lives and the lives of others.
“Anyone who is considering driving whilst under the influence of drink or drugs should know that we will be out and about waiting.”
Social media users can follow the campaign via the #ChooseWisely and #Fatal5 hashtags.