A man had his licence suspended after recording a blood alcohol reading of 0.087.
Acting Sergeant Michael Vaughan, of Portland police, said the man was intercepted in Gore Place about 5.30am on Sunday morning.
"Police intercepted the vehicle of a 47-year-old South Australian man," Acting Sergeant Vaughan said.
"He has had his license suspended for six months."
Acting Sergeant Vaughan reminded motorists they could be stopped and asked to complete a preliminary breath test at any time of the day or night.
"We're always out and about and very vigilant when it comes to drink driving," he said.
Have you signed up to The Standard's daily newsletter and breaking news emails? You can register below and make sure you are up to date with everything that's happening in the south-west.