"When spoken to by police the defendant stated that it was a wide road and that his speed was not hurting anyone."
The court was told Fagan had a clean driving record and had never appeared in court before.
Community magistrate Janet Holmes noted that he was "well over twice the legal limit", and took into account his early guilty plea.
He was convicted and fined $750, disqualified from driving for six months, and ordered to pay court costs of $130.
Fagan hosts an evening radio show on Radio Live with his wife, Karyn Hay.
He was frontman for the 80s band The Mockers, and now performs with his current band The People.