More than 140 motorists were detained for drink and drug drive offences last month.
North Wales Police administered 2,546 breath tests as part of the All Wales Christmas Anti Drink and Drug Drive campaign, with 56 drug drive arrests being made.
During the same period, 87 breath tests were positive, failed or refused.
North Wales Police officers used intelligence-led tactics and local knowledge of hotspots to detect people who were driving under the influence of drugs or alcohol over the festive period.
As part of the campaign, disposable breath test kits were distributed to staffed police station front counters across the region for collection by members of the public to use at home prior to driving the morning after.
Inspector David Cust from the Roads Policing Unit said: “We have received an overwhelming positive response to the disposable breath test kits.
“Many have told us it stopped them from driving the morning after having indicated that alcohol was still present in their systems.
“From our point of view if it prevented one person from taking a risk then they’ve done their job. Throughout the campaign our message remained the same - if you’ve been drinking don’t drive.
“Although the festivities are now over, we continue to remind motorists of the message that drink or drug driving is unacceptable all year round.
“Despite the repeated warnings that we would be out and about, 143 motorists were arrested as part of this campaign.
“If convicted, each will be disqualified from driving for at least 12 months; face a heavy fine and many could lose their jobs.”
Throughout 2017 North Wales Police made 882 drink drive and 600 drug drive arrests.
Insp Cust added: “Our teams will remain alert to the threat of people who are driving under the influence of intoxicants and will continue to catch those who take this risk and endanger innocent road users.”
Throughout the campaign period the force Roads Policing Unit used social media to drive home the message of the impact of drink and drug driving.
For the first time officers gave their own accounts of what it is like to deal with the aftermath of a collision involving a drink or drug driver using the hashtags #ChooseWisely and #Fatal5.
If someone is suspected of driving while unfit to do so, report it immediately to police on 101 - 999 if they are posing imminent danger - or phone it through anonymously to Crimestoppers on 0800 555 111.