An insurance team manager failed to calculate the risk when he was caught drink-driving.
Adam Hollinger, 27, of Awdry Drive, Wisbech, admitted the offence at King’s Lynn Magistrates’ Court last week.
He was caught in King’s Lynn in the early hours of August 22, when moving his car to a free overnight car park.
A breath test at the police station later revealed 75 micrograms of alcohol in 100 millilitres of breath – the legal limit is 35.
He was banned from driving for 18 months and fined £400, with £275 court costs.