Dean Martin Sullivan (58) drove his white Ford transit van at 37mph along a stretch of Les Ruisseaux with a 15mph speed limit on 3 July.
Police officers carrying out speed checks had spotted Sullivan at 10:40 at that morning.
He told the Magistrate’s Court: “I made a mistake. It was a lapse of judgement.”
Relief Magistrate Nunes Da Costa said: “Doing 37mph in a 15mph area is serious, and needs to be dealt with accordingly.”
He endorsed his licence for three years along with imposing the fine.