A man found exceeding the speed limit on the motorway was convicted for careless driving at Naas District Court on December 6.
John Mills, 36, whose address was given as 67 Kylemore Avenue, Ballyfermot, was found driving on January 19 last on the M9 at Kilgowan.
Sgt Jim Kelly said traffic was light at the time and weather conditions were good.
He was detected driving at 161 km/h in a 120 km/h zone.
The court heard that the defendant had some previous convictions but some were “very historical”.
Barrister Sarah Connolly said the man was bringing his son to a match and he had pulled in immediately.
Ms Connolly also said that the speedometer in the vehicle was calibrated in miles per hour.
He didn’t realise the speed he was travelling at and had taken his eye off the speedometer.
The man was disqualified for a year and fined €500.