Dyfed Powys Police are urging people to think about their alcohol in take on a night out if they are planning to drive the following day.
Police in Pembrokeshire are carrying out random stop checks as part of the winter drink driving campaign at all times of the day and night.
This weekend one man was found to be twice over the legal limit the morning after a night out.
Inspector Andy Phillips said: “The campaign is all about ensuring our roads are safe.
“We are carrying out daily checks and have spoken to 100s of drivers who have been supportive of our action and we thank them for their co-operation.
“We are urging people not to drink and drive on a night out but also to think about the morning after.
“It can take a long time for alcohol to leave your system and although you may think you are just hung over you could still be over the legal limit and a danger to yourself and other road users.
“Thinking about what you are drinking can also have an effect on your behaviour that night preventing you from maybe having that one extra drink which could cause you to act out of character.
“Having a criminal conviction for drink driving or disorder can effect your life for years to come.
“We are hoping everyone takes our advice and has a safe Christmas and a crime free 2010.”