A REPORT that a driver on the A30 was possibly under the influence of drink led officers to her in her car at Redruth.
Karen Ross failed a roadside breath test and later registered 56mcg alcohol in breath, 21 points over the legal limit, on July 18.
At Truro Magistrates' Court Ross, 51, of Treskillard, Redruth, pleaded guilty to drink-driving.
Nicola Carter, for the Crown Prosecution Service, said she was seen by the officers to be driving erratically and almost clipping the verge on to a roundabout. She admitted to them she had been drinking.
She had no previous convictions and was fined £500 and £100 costs and surcharge and banned from driving for a year.