Twelve drivers were pulled over on Saturday and Sunday morning and found to be over the alcohol limit.
"If drivers have been drinking heavily the night before, they shouldn't get behind the wheel the next morning. Alcohol stays in the system a long time and their driving skills can still be impaired even after sleep.
"Not only that, but the weather conditions were variable on Sunday with extreme wind and rain."
Mr Williams said: "It's less about drink driving, it's about stupidity, I think.
"We do a lot of advertising and send a lot of information to accommodation providers, all the bus and transport companies."