New cameras are going live at midnight to catch drivers speeding through the Port Tunnel. The new technology detects those breaking the limit by tracking the average speed of motorists.
The new safety system was announced last June, and sees cameras placed at the entrance and exit, and calculate the speed a car or truck is doing over a 4.5 kilometre distance.
The Transport Minister, Shane Ross, said "Any initiative that has the potential to save lives and reduce serious injuries on our roads is to be welcomed."
Any motorist doing the journey in less than 3 minutes and 30 seconds is breaking the 80 kilometre an hour limit and will receive a fine and penalty points. The camera positions cover both lanes so motorists won't be able to avoid them by switching lanes.
Assistant Commissioner Michael Finn, Roads Policing, said "this new average speed enforcement system provides additional support toward maintaining a safe travel experience for all users of the Tunnel."
Officials say traffic in the Port Tunnel has increased 40% in the last 5 years, and it's hoped the introduction of the average speed cameras will cut the number of crashes in half.
All drivers using the Port Tunnel should notice large yellow poles, which support the new cameras. Unlike traditional speed cameras, these ones won't flash if a driver is speeding but Gardai warn they are always on.
Anyone caught speeding though the tunnel will be fined €80 and hit with 3 penalty points, which will increase if they end up in court.