Police forces are preparing to crack down on drivers who get behind the wheel after drinking or taking drugs ahead of the festive season.
Drivers will be breathalysed and also checked for drugs during the campaign after a change to the law last spring.
Nearly 23,000 motorists were breathalysed during the operation last December.
This year's month long campaign, led by South Wales Police, launches today in Merthyr Tydfil.
More than 500 drivers failed drink driving tests during last year's clampdown, with almost 100 more drivers arrested for getting behind the wheel after taking drugs.
Assistant Chief Constable Jeremy Vaughan, South Wales Police said forces would take a zero tolerance approach to those who break the law.
"As Christmas is all about spending time with friends and family, our campaign focuses on showing the true impact either committing or falling victim to this crime can have on the communities of Wales," he said.
"Since the improvements of roadside testing for alcohol and drugs, there is nowhere to hide for those that break the law."
Susan Storch, chairwoman of Road Safety Wales said "Following years of education, enforcement and publicity, the vast majority of drivers have taken the ‘Don’t Drink and Drive’ message to heart and we thank everyone who continues to take this on board. Working with our partners in the Police, Road Safety Wales is reminding all drivers and riders of their responsibility to always drive sober and free from illegal drugs and to never accept a lift from someone they suspect has been drinking or taking drugs. Those who take over-the-counter or prescribed medication are encouraged to speak to their Doctor or Pharmacist about any effects this may have on their driving. Please enjoy the festive period and get home safely"