Around €320,000 has been generated as result of fines issued in Dublin's Port Tunnel over the last six months.
4,000 drivers have been caught travelling through the new 'average speed' detection system too quickly since its introduction in June.
Fines are issued if a motorist enters and exits the tunnel in a time of less than three minutes and 36 seconds.
Those who commit the offence also get three penalty points on their licence, increasing to five, and an increased fine if convicted in court.
- Digital Desk