Almost 4,000 drivers were caught drink-driving in Wales last year and 57,000 in the UK, says Confused.com.
South Wales Police dealt with almost 1,700 drivers while almost a quarter of all motorists polled said they had driven the morning after a heavy session. December was the worst month of offences.
North Wales recorded 882 failed breath tests in 2016, Dyfed Powis 872 and Gwent 400.